IGCSE Notes (Computer Science, Business Studies, Physics, Biology, Chemistry and Mathematics)

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TABLE OF CONTENTS
2
CHAPTER 1
4
CHAPTER 2
6
CHAPTER 3
10
CHAPTER 4
12
CHAPTER 5
Data Representation
Communication & Internet Technologies
Hardware & Software
Security
Ethics
CIE IGCSE COMPUTER SCIENCE//0478
1. DATA REPRESENTATION
1.1 Binary Systems
 The binary system is based on the number 2
 Made up of 1s and 0s
 Use of binary numbers in computer systems
Converting Binary to Denary
 To calculate a binary number like, 10101000, place it in
columns of base 2 numbers
 Then add all the base 2 numbers
128
64
32
16
8
4
2
1
1
0
1
0
1
0
0
0
128 + 32 + 8 = 
Converting Denary to Binary
 To calculate a denary number like, 84, set up the
columns of base 2 numbers
128
64
32
16
8
4
2
1
0
1
0
1
0
1
0
0

1.2 Measurement of the Size of Computer
Memories
 A binary digit is referred to as a BIT, 8 bits is a byte
 Byte is used to measure memory size
NAME OF
NO. OF
EQUIVALENT DENARY VALUE
MEMORY SIZE
BITS
1 kilobyte (1KB)
210 1 024 bytes
2 megabyte (1MB)
220 1 048 576 bytes
1 gigabyte (1GB)
230 1 073 741 824 bytes
1 terabyte (1TB)
240 1 099 511 627 776 bytes
1 petabyte (1PB)
250 1 125 899 906 842 624 bytes
Example use of binary
 A register is a group of bits, often depicted as:
o 
 Robotics
 Digital instruments
 Counting systems
HEXADECIMAL
DENARY VALUE
VALUE
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
A
10
B
11
C
12
D
13
E
14
F
15
Converting Binary to Hexadecimal
 To convert binary number 01100001
o Separate into two nibbles (4 bits)
o Convert nibbles to denary
o Change denary numbers to hex if needed (e.g. 10 = A)
8
4
2
1
8
4
2
1
0
1
1
0
0
0
0
1
=6
=1
ℎ  
Converting Hexadecimal to Binary
 To convert hex value 6C
o Change hex value to denary numbers (e.g. 12 = C)
o Separate hex value and convert to 4 bit binary value
o Put the two nibbles together to form an 8 bit binary
ℎ  6  
8
0
4
1
2
1
ℎ   (12)  
1
8
0
1

4
1
2
0
Converting Denary to Hexadecimal
 To convert denary number 98
1.3 Hexadecimal
o Convert to binary
 Closely related to the binary system
o Split the binary (8bits) into nibbles (4bits)
 Hexadecimal is a base 16 system
o Find the values separately
 Numbers 0 to 9 and letters A to Fare used to represent
128 64 32 16
8
4
2
each hexadecimal digit
0
1
1
0
0
0
1
 A =10, B = 11, C = 12, D = 13, E = 14, F = 15
8
4
2
1
8
4
2
=
=
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1
0
1
0
1
CIE IGCSE COMPUTER SCIENCE//0478
Converting Hexadecimal to Denary
 To convert hex value 2B
o Split the hex value into two
o Convert each number to binary
o Put the two binary numbers together
o Convert to denary
ℎ   (11)  
ℎ  2  
8
0
128
0
4
0
64
0
2
1
32
1
Automatic Repeat Request (ARQ)
 ARQ is another method to check if data has been
transmitted correctly
 It uses and acknowledgement (message sent by the
receiver indicating that data has been received correctly)
1
0
16
0
8
1
8
1
4
0
4
0
2
1
2
1
1
1
1
1
Checksum
 Checksum is another way to see if data has been
transmitted correctly
 Data is sent in blocks and an additional value sent at the
end of the block
= 
Echo check
 When data is sent to another device, this data is sent
back again to the sender
 The sender compares the two sets to check if any errors
occurred
 Not reliable
1.4 Use of the Hexadecimal System
 Examples:
o defining colours in Hypertext Markup Language
(HTML)
o Media Access Control (MAC) addresses
o Assembly languages and machine code
o Debugging
1.6 File types
Memory Dumps
 Hexadecimal is used when developing new software or
when trying to trace errors
 Memory dump is when the memory contents are output
to a printer, monitor.
Assembly code and machine code (low level languages)
 Computer memory is machine code/ assembly code
 Using hexadecimal makes it easier, faster, less error
prone to write code compared to binary.
 Using machine code (binary) takes a long time to key in
values and prone to errors
1.5 Error Checking
Parity Checking
 Parity checking is used to check weather data has been
changed or corrupted following transmission from one
device to another
 A byte of data is allocated a parity bit
o Systems that use even parity have an even number of
1-bits
o Systems that use odd parity have an even number of
1-bits
Musical Instrument Digital Format (MIDI)
 Storage of music files
 Communications protocol that allows electronic musical
instruments to interact with each other
 Stored as a series of demands but no actual music notes
 Uses 8-bit serial transmission (asynchronous)
 Each MIDI command has a sequence of bytes:
o First byte is the status byte – informs the MIDI device
what function to preform
o Encoded in the status byte is the MIDI channel
(operates on 16 different channels)
 Examples of MIDI commands:
o Note on/off: indicates that a key has been pressed
o Key pressure: indicates how hard it has been pressed
(loudness of music)
 Needs a lot of memory storage
MP3
 Uses technology known as Audio Compression to
convert music and other sounds into an MP3 file format
 This compression reduces the normal file size by 90%
o Done using file compression algorithms which use
Perceptual Music Shaping
o Removes sounds that human ear cannot hear properly
o Certain sounds are removed without affecting the
quality too much
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CIE IGCSE COMPUTER SCIENCE//0478
 CD files are converted using File Compression Software
 Use lossy format as the original file is lost following the
compression algorithm
MP4
 This format allows the storage of multimedia files rather
than just sound
 Music, videos, photos and animations can be stored
 Videos, could be streamed without losing any real
discernible quality
Joint Photographic Experts Group (JPEG)
 JPEG is a file formats used to reduce photographic file
sizes
 Reducing picture resolution is changing the number of
pixels per centimetre
 When photographic file undergoes compression, file size
is reduced
 JPEG will reduce the raw bitmap image by a factor
between 5 and 15
2.2 Serial & Parallel Transmission
 Serial data transmission is when data is sent one bit at a
time over a single wire
o Works well over long distances
o Data transmitted at a slower rate (USB)
 Parallel data transmission is when data several bits (1
byte) are sent down several wires at the same time
o Works well over short distance
o Faster method (internal components use parallel for
high speed)
2.3 Simplex, Half-duplex and Full-duplex
 Simplex data transmission is in one direction only (e.g.
computer to printer)
 Half-duplex data transmission is in both directions but
not at the same time (e.g. phone conversation where
only one person speaks)
 Full-duplex data transmission is in both directions
simultaneously (e.g. broadband connection on phone
line)
2.4 Universal Serial Bus (USB)
1.7 Lossless and Lossy File Compression
Lossless File Compression
 All the data bits from the original file are reconstructed
when the file again is uncompressed
 Important for files where loss of data would be
disastrous (spreadsheet)
Lossy File Compression
 The file compression algorithm eliminates unnecessary
bits of data like MP3 and JPEG formats
 Impossible to get original file back once compressed
2. COMMUNICATION & INTERNET TECHNOLOGIES
 USB is an asynchronous serial data transmission method
 USB consists of:
o Four-wire shielded cable
o Two wires used for power and earth
o Two wires used in data transmission
ADVANTAGES
Automatically detected
Only fit one way,
prevents incorrect
connections
Different data
transmission rates
DISADVANTAGES
Maximum cable length is
about 5 metres
Transmission rate is less
than 500 mb/sec
2.1 Transmission of Data
 Asynchronous data transmission refers to data being
transmitted in an agreed bit pattern
o Data bits are grouped together & sent with control bits
o This means the receiver of the data knows when the
data starts and ends, prevents data getting mixed up
 Synchronous data transmission is a continuous stream of
data (not in discrete groups like asynchronous)
o Ensures that the sender and receiver are synchronised
with each other
o Faster method
2.5 Security Aspects
Hacking
 The act of gaining illegal access to a computer system
 Effect:
o Leads to identity theft, gaining personal information
o Data can be deleted, changed or corrupted
 To remove risk:
o Firewalls
o Strong passwords/ user IDs
o Use of anti-hacking software
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CIE IGCSE COMPUTER SCIENCE//0478
 Difference between hacking and cracking
o Hacking breaks into computer system to steal data
o Cracking is where someone edits a program code,
malicious
Viruses:
 Program that can replicate itself with the intention of
deleting or corrupting files, cause computer malfunction
 Effect:
o Can cause computer to crash
o Can delete or corrupt files/data
 To remove risk:
o Install anti-virus software
o Don’t use software from unknown sources
o Be careful when opening emails from unknown
Wardriving:
 The act of locating and using wireless internet
connections illegally
 Effects:
o Possible to steal internet time
o Possible to hack into wireless network and steal user’s
password
 To remove risk:
o Use complex passwords
o Firewalls
Spyware:
 Software that gathers info by monitoring key presses on
the user’s keyboard and info is sent back
 Effects:
o Access to all data entered
o Software is able to install other spyware, read cookie
data
 To remove risk:
o Use of anti-spyware software
o Use a mouse to select characters from passwords
rather than typing them
2.6 Internet Principles of Operation
 Internet Service Protocol: These are companies that
provide user with access to the internet
Internet Protocol (IP) Address
 Each device on the internet is given a unique address
known as the IP address
 32-bit number written in the form: 109.108.158.1
 IP address gives the location of a device on the internet
whereas the MAC address identifies the device
connected to the internet
 IP address changes, MAC address remains unchanged
HTML (HyperText Mark-up Language)
 Used when writing and developing pages
 Mark-up language is used in the processing
 Html use <tags> to bracket piece of codes
 Different intensity of colours is determined by its
hexadecimal value
Media Access Control (MAC)
 MAC address refers to a number which uniquely
identifies a device on the internet
 Refers to the network interface card (NIC) which is part
of the device
 Usually made up of 48 bits shown as six groups of
hexadecimal digits
 NN:NN:NN:DD:DD:DD
o (NN:NN:NN) first half is the identity number of the
manufacturer of the device
o (DD:DD:DD) second half is the serial number of the
device
 Types of MAC Address:
o Universally Administrated MAC Address (UAA)
o Locally Administrated MAC Address (LAA)
o UAA is the most common type set by the
manufacturer
 Reasons to change MAC address using LAA
o To ensure they follow the correct formula
o To bypass MAC address filter on a router or a firewall
o To get past certain types of network restrictions
Web addresses
 Each character on the keyboard has its own ASCII code
 Can be represented using hexadecimal or decimal values
 Hexadecimal addresses are used in the address of files or
webpages as a security figure
 Takes longer to type in URL but advantage is that you are
unlikely to fall into the trap of copying a fake website
Cookies
 A packet of information sent by a web server to a web
browser
 Generated each time the user visits the website
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CIE IGCSE COMPUTER SCIENCE//0478
 Every time a user visits a website, cookies will have
collected some key information about the user
 They are able to carry out user tracking and maintain
user preferences
 Cookies are pieces of data
 Information gathered by cookies doesn’t contain
personal information
3. HARDWARE & SOFTWARE
3.1 Logic Gates
 Logic Gates: use one or more inputs and produces a
single logical output
 AND gate: If both inputs high, output is high
. 
A
B
Output
0
0
1
1
 OR gate: If either inputs
high, output is high
+
0
1
0
1
A
0
0
1
1
B
0
1
0
1
0
0
0
1
Output
0
1
1
1
 NOT gate: an inverter
̅
A
1
0
Output
0
1
 NAND gate:
̅̅̅̅̅
. 
A
0
0
1
1
B
0
1
0
1
A
0
0
1
1
B
0
1
0
1
 NOR gate:
̅̅̅̅̅̅̅̅
+
 XOR gate:
̅̅̅̅̅̅̅̅
⨁
A
0
0
1
1
B
0
1
0
1
Output
0
1
1
0
3.2 Computer Architecture & Fetch-Execute
Cycle
Computer Architecture
 Address bus – unidirectional
 Data bus – bi-directional
 Control bus – unidirectional and bi-directional
 Processor: The processor contains the Arithmetic and
Logic Unit (ALU)
 Control Unit: The control unit controls the operation of
the memory, processor and input/output devices
The Fetch-Execute Cycle
1. PC contains address of the next instruction to be
fetched
2. This address is copied to the MAR via the address bus
3. The instruction of the address is copied into the MDR
temporarily
4. The instruction in the MDR is then placed in the CIR
5. The value in the PC is incremented by 1, pointing the
next instruction to be fetched
6. The instruction is finally decoded and then executed
3.3 Input Devices
SCANNERS:
Two-dimensional Scanners:
 Used to input hard-copy documents
 The image is converted into an electronic form which
Output
1
can be stored in the computer
1
o Document is placed on a glass panel
1
o A bright light illuminates the document
0
o A scan head moves across the document until the
whole page is scanned. And image of the document is
produced and sent to a lens using a series of mirrors
Output
o The lens focuses the document image
1
o The focused image now falls onto a charge couple
0
device (CCD) which consists of a numbers of integrated
0
circuits
0
o Software produces a digital image from the electronic
form
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CIE IGCSE COMPUTER SCIENCE//0478
 Optical Character Recognition (OCR) is a software which
converts scanned documents into a text file format
 If the original document was a photo/image, then the
scanned image forms an image file such as JPEG
Three-dimensional Scanners
 3D scanners can scan solid objects and produce a threedimensional image
 Scanners take images at several points, x, y and z (lasers,
magnetic, white light)
 The scanned images can be used in Computer Aided
Design (CAD) or to a 3D printer to produce a working
model
Application of 2D Scanners at an Airport:
 Make use of (OCR) to produce digital images which
represent the passport pages
 Text can be stored in ASCII format
 The 2D photograph in the passport is also scanned and
stored as jpeg image
 The passenger’s face is also photographed using a digital
camera and compared using face recognition software
 Key parts of the face are compared (distance between
eyes, width of nose)
Barcode readers/scanners
 A barcode is a series of dark and light parallel lines of
varying thicknesses
 The numbers 0 -9 are each represented by a unique
series of lines
 The left and right hand sides of the barcode are separate
using guard bars
 Allows barcode to be scanned in any direction
o Barcode is read by a red laser or red LED
o Light is reflected back off the barcode; dark areas
reflect little light which allows the bars to be read
o Reflected light is read by sensors (photoelectric cells)
o Pattern is generated which is converted to digital
Quick Response (QR) Codes
 Another type of barcode is the QR codes
 Made up of a matrix of filled in dark squares on a light
background
 Can hold more storage (7000 digits)
 Advantages of QR codes:
o No need for the user to write down website address
o QR codes can store website addresses
Digital Cameras
 Controlled by microprocessor which automatically
adjusts the shutter speed, focus the image, etc.
 Photo is captured when light passes through the lens
onto a light sensitive cell
 Cell is made up of pixels
 Number of pixels determines size of the file
Keyboards
 Connected to computer with a USB connection or by
wireless connection
 Each character has an ASCII value and is converted into a
digital signal
 Slow method
 Prone to errors
Pointing devices
 Mouse/trackball
o Traditional; mechanical ball, connected by USB port
 Modern type; red LEDs to detect movement
Microphones
 Used to input sound to a computer
 When a microphone picks up sound, a diaphragm
vibrates producing an electric signal
 The signal goes to a sound card and is converted into
digital values and stored in computer
 Voice recognition, voice is detected and converted into
digital
Touchscreens
 Capacitive (medium cost tech)
o Made up of many layers of glass
o Creating electric fields between glass plates in layers
o When top layer of glass is touched, electric current
changes
o Co-ordinates where the screen was touched is
determined by an on-board microprocessor
 Infra-red heat (expensive)
o Use glass as the screen material
o Needs warm object to carry an input operation
 Infra-red optical (expensive)
o Uses glass as screen material
o Uses an array of sensors (grid form)
o Point of contact is based on which grid co-ordinate is
touched
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CIE IGCSE COMPUTER SCIENCE//0478
 Resistive (inexpensive)
o Upper layer of polyester, bottom layer of glass
o When the top polyester is touched, the top layer and
bottom layer complete a circuit
o Signals are then sent out which are interpreted by a
microprocessor, determine where screen was touched
Sensors
 Devices which read or measure physical properties
 Data needs to be converted to digital
 Analogue to Digital Converter (ADC) converts physical
values into digital
Control of Street Lighting
 Light sensor sends data to the ADC
 Digitises data and sent to the microprocessor
 Microprocessor samples data every minute
 If data from sensor < value stored in memory:
o Signal sent from microprocessor to street lamp
o Lamp switched on
3D Printers
 Used for models of cars
 Produce solid objects that work
 Built up layer by layer, using powdered resin, ceramic
powder
 A design is made using Computer-aided Design (CAD)
3.4 Output Devices
PRINTERS:
Inkjet Printers
 Used to print one-off pictures and documents
1. Data from document sent to printer driver
2. Printer driver ensures data is in correct format
3. Check made by printer driver that chosen printer is
available
4. Data is sent to printer, stored in a temporary memory
(printer buffer)
5. Sheet of paper is fed; sensor detects if paper is available
in paper tray
6. Print head moves across paper printing text/image, four
ink colours sprayed in exact amount
7. Paper is advanced so next line is printed
8. Repeated until buffer is empty
9. Once it is done, printer send an interrupt to the
processor (request for more data to be sent)
Laser Printers
 Used to print flyers, high quality
 Use dry powder ink (toner) and static electricity to
produce text and images
 Prints the whole page in one go
1. (steps 1-4 same as inkjet)
2. Printing drum is given a positive charge; as the drum
rotates, a laser beam is scanned across it removing the
positive charge leaves negatively charged areas which
match the text/image
3. Drum is then coated with positively charged toner, it
only sticks to negatively charged parts of the drum
4. A negatively charged sheet is rolled over the drum
5. Toner on the drum now sticks to the paper to produce
copy of page
6. Paper finally goes through a fuser (set of heated
rollers); heat melts the ink so it is permanent
7. Discharge lamp removes all electric charge from the
drum, ready to print next page
2D and 3D Cutters
 3D cutters can recognise objects in x, y, z direction
 3D laser cutters can cut; glass, crystal, metal, wood
Actuators
 Used in many control applications involving sensors and
devices (ADC and DAC)
Loudspeakers/Headphones
 Sound is produced by passing the digital data through a
DAC then through amplifier and then emerges from
loudspeaker
 Produced by voltage differences vibrating a cone in the
speaker at different frequencies
LCD and LED Monitors
 Front layer of monitor is made up of Liquid Crystal
Display (LCD), these tiny diodes are grouped together in
threes as pixels (LCD doesn’t emit any light)
 LCD monitors are back lit using Light Emitting Diode
(LED) because:
o LEDs reach their maximum brightness immediately
o LEDs sharpens image (higher resolution), CCFL has
yellow tint
o LEDs improve colour image
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o Monitors using LED are much thinner than CCFL
o LEDs consume very little power
 Before LEDs, LCD monitors were backlit using CCFL
 CCFL uses two fluorescent tubes behind the LCD screen
which supplies the light source
LIGHT PROJECTORS:
 Two common types of light projectors:
o Digital Light Projector (DLP)
o LCD Projector
 Projectors are used to project computer output onto
larger screens/interactive whiteboards
Digital Light Projectors (DLP)
 Uses millions of micro mirrors
 the number of micro mirrors and the way they are
arranged on the DLP chip determines the resolution of
the image
 When the micro mirrors tilt towards the light source
they are on
 When the micro mirrors tilt away from the light source
they are off
 This creates a light or dark pixel on the projection screen
 A bright white light source passes through a colour filter
on its way to the DLP chip
 White light splits into primary colours
LCD Projectors
 Older technology than DLP
 A powerful beam of white light is generated from a bulb
 This beam of light is then sent to a group of chromaticcoated mirrors; these reflect the light back at different
wavelengths
 When the white light hits the mirrors, the reflected light
has wavelengths corresponding to red, green and blue
 These three different light pass through three LCD
screens; these screens show the image to be projected
as millions of pixels in grayscale
 When the coloured light passes through the LCD screens,
a red, green and blue version of the grey image emerges
 Finally, the image passes through the projector lens onto
the screen
3.5 Memory, Storage Devices & Media
PRIMARY MEMORY:
Random Access Memory (RAM)
 Features of RAM
o Volatile/temporary memory (contents lost if RAM is
turned off)
o Used to store; data, files
o It can be written to or read from and the contents
from the memory can be changed
 Larger the size of the RAM, faster the computer will
operate
 RAM never runs out of memory, continues to run slow
 As RAM becomes full, the processor has to continually
access the hard drive to overwrite old data on RAM with
new data
Read Only Memory (ROM)
 Features of ROM
o Non-volatile/permanent memories (contents remain
even when ROM is turned off)
o Used to store start up instruction (basic input/output
systems)
o Data/contents of a ROM chip can only be read, cannot
be changed
SECONDARY STORAGE:
Hard Disk Drives (HDD)
 Data is stored in a digital format on the magnetic surface
of the disks (platter)
 Number of read/write heads can access all of the
surfaces of the disk
 Each platter will have two surfaces which can be used to
store the data
 Data is stored on the surfaces in sectors and tracks
 HDD have very slow data access compared to RAM
Solid-State Storage (SDD)
 No moving parts and all data is received at the same
time (not like HDD)
 Store data by controlling the movement of electrons
within NAND chips, as 1s and 0s
 Non-volatile rewritable memory
 Benefits of using SDD rather than HDD:
o More reliable (no moving parts)
o Considerably lighter (suitable for laptops)
o Lower power consumption
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o Run much cooler than HDDs
o Very thin
o Data access if faster than HDD
 Drawback – questionable longevity (20GB per day)
OFF-LINE STORAGE
CD/DVD Disks
 Laser (red) light is used to read and write data in the
surface of the disk
 Use a thin layer of metal alloy to store data
 Both systems use a single, spiral track which runs from
the centre of the disk to the edge
 DVD uses Dual-Layering which increases the storage
capacity (two individual recoding layers)
Blu-ray Disks
 Uses blue laser to carry out read and write operations
 Wavelength of laser light is less than CD and DVD (stores
up to five times more data than DVD)
 Automatically come with secure encryption (prevent
piracy and copyright infringement)
 Used as back-up systems
USB Flash Memories
 Very small, lightweight suitable from transferring files
 Small back-up devices for photo, music
 Solid state so need to be treated with care
3.6 High- & Low-Level Languages
High-Level Languages
 Easier to read and understand as the language is closer
to human language
 Easier to write in shorter time
 Easier to debug at the development stage
 Easier to maintain once in use
Low-Level Languages
 Refer to machine code
 Binary instructions that computer understands
TRANSLATORS:
 A program must be translated into binary before a
computer can use it
 Types of translators; Compiler, Interpreter and
Assembler
Compiler
 Translates a program written in high-level language into
machine code
 Used without compiler
 Executable file of machine code produced
 One high-level language translated into several machine
code instructions
 Used for general use
Interpreter
 Executes a high-language program a statement at a time
 No executable file of machine code produced
 One high-level language program statement may require
several machine code instructions to be executed
 Cannot be used without interpreter
 Used when program is being developed
Assembler
 Translates a low-level language program into machine
code
 Executable file of machine code produced
 One low-level language translated into one machine
code instructions
 Can be used without assembler
 Used for general use
Syntax Errors:
 When program is being compiled, if any syntax errors
are found no translated program is produced
 Instead, a list of all errors in program is produced
 Programmer corrects program and recompiles
 When a program is being interpreted, the interpreter
preforms the action until syntax error is found
 The programmer is the alerted to the place in the
program where error was found
 The error is corrected and interpretation continues
4. SECURITY
 Need to keep data safe from accidental damage,
including corruption and human errors
 Need to keep data safe from malicious actions, including
unauthorised viewing, deleting, copying and corruption
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CIE IGCSE COMPUTER SCIENCE//0478
4.1 Firewalls & Proxy Servers
4.3 Encryption
 A firewall sits between the user’s computer and an
external network (internet) and filter information in and
out of the computer
 Tasks carried out by firewall:
o Examining ‘traffic’
o Checking weather incoming or outgoing data meets
criteria
o If data fails the criteria, the firewall blocks ‘traffic’
o Firewall can keep a list of all undesirable IP addresses
o Helping to prevent viruses or hackers entering the
user’s computer
 Proxy servers act as an intermediary between the user
and a web server
 Functions of proxy servers:
o Allowing the internet ‘traffic’ to be filtered
o By using cache, they can speed up access to
information from a website
o Keeping the user’s IP address secret
 Acting as a firewall
 Used to protect data in case it has been hacked
 Doesn’t prevent hacking, makes data meaningless
4.2 Security Protocols
Secure Sockets Layer (SSL)
 Type of protocol that allows data to be sent and received
securely over the internet
 When a user logs onto a website, SSL encrypts the data
 https or padlock in the status bar
 When user wants to access a secure website:
o User’s web browser sends a message so it can connect
with required website which is secured by SSL
o Web browser requests that the web server identifies
itself
o Web server responds by sending a copy of its SSL
certificate
o Web browser checks if certificate is authentic
o Sends signal back to web browser
o Starts to transmit data once connection is established
o If not secure, browser will display an open padlock
Symmetric Encryption
 A secret key which can be a combination of characters
 If this key is applied to a message, its contents is
changed
 One key is needed to encrypt a message and another key
is needed to decrypt a message
 Increasing the length of the key increases the strength of
the encryption
Plain text and Cypher Text
 Plain text is the normal representation of data before it
goes through an encryption algorithm
 Cypher text is the output from an encryption algorithm
Authentication
 Authentication is used to verify that data come from a
trusted source
 Works with encryption to strengthen internet security
 Passwords: usually a user id/name and password are
used to log on to systems
 Digital Signatures: public key encryption; ensure an
electronic document is authentic
 Biometrics: relies on the unique characteristics of human
beings (fingerprint scans, retina scans)
4.4 Phishing, Pharming & DoS
Phishing:
 Creator sends out a legitimate-looking email; as soon as
recipient clicks on link, user is sent to a fake website
 Effect:
o Creator of email can gain personal data; bank account
o Can lead to fraud
 To remove risk:
o Many ISPs filter out phishing emails
o User should be cautious
Pharming
 Malicious code installed on a user’s hard drive or on the
web server, code will redirect the user to a fake website
 Effect:
o Creator of malicious code can gain personal data; bank
account
o Can lead to fraud or identity theft
Transport Layer Security (TLS)
 Form of protocol that ensures the security and privacy of
data between devices and users when communicating
over the internet
 Designed to provide encryption, authentication and data
integrity in a more effective way than SSL
 Possible to extend TLS by adding new authentication
methods
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CIE IGCSE COMPUTER SCIENCE//0478
 To remove risk:
o Some anti-spyware can identify and remove pharming
code from hard drive
o User should be alert
Denial of Service Attacks (DoS)
 An attempt at preventing users from accessing part of a
network
 Usually temporary but may be damaging
 Attacker me be able to prevent user from:
o Accessing their emails
o Accessing websites
o Accessing online services
Shareware
 All the features of the full version of software are not
made available; full version needs to be purchased first
 Subject to all copyright laws
 Permission needs to be obtained before software is
copied and given to friends or family
4.5 Applications
 Ways bank protect their costumers from online fraud
o Banks use 10/12-digit code unique to the costumer
o May be asked to input three random numbers from a
four-digit PIN
o Some use a hand-held device into which a customer
inserts their card. Device will generate an eight-digit
code which the customer types into web page
o Some ask to key in parts of their passwords using
drop-down boxes (using a mouse)
5. ETHICS
 A set of principles set out to regulate the use of
computers
 Plagiarism is when a person takes another person’s
idea/work and claims it as their own
5.1 Types of Softwares
Free Software
 Software source code can be freely accessed and
modified as required
 Run, copy, change or adapt free software (e.g. Scribus,
Abiword)
 Possible to distribute modified versions of software to
friends and family
Freeware
 A software a user can download from the internet free
of charge
 Once it has been downloaded, there are no fees
associated (e.g. Adobe, Skype)
 Subject to all copyright laws
 User is not allowed to study, modify code
PAGE 12 OF 12
TABLE OF CONTENTS
2
CHAPTER 1
3
CHAPTER 2
Algorithm Design & Problem Solving
Programming
4 Databases
CHAPTER 3
CIE IGCSE COMPUTER SCIENCE//0478
• Functions are sub-routines that return a single value
1. ALGORITHM DESIGN & PROBLEM-SOLVING
• Trace Tables: A technique used to test algorithms, in
order to make sure that no logical errors occur whilst the
algorithm is being processed.
1.1 Problem-solving & Design
• Every computer system is made up of sub-systems,
which are in turn made up of further sub-systems.
• Top-down Design – The breaking down of a computer
system into sub-systems, then breaking each sub-system
into smaller sub-systems, until each one only performs a
single action. A structure diagram diagrammatically
represents top-down design. Example below.
• Test data – All the items of data required to work
through a solution. It is inputted into the program and
compared with the expected results. Examples are for a
school grade
o Normal – 28; 64; 98 - Accept
o Erroneous/Abnormal – eleven; -12; 158 - Reject
o Extreme – 0; 100 – Accept
o Boundary – 0; -1 – Accept; Reject
• Validation – Automated checking by a program that data
is reasonable before it is accepted as an input.
o Range – Accepts numbers within a specified range
o Length – Accepts data with an exact number of
characters OR has a reasonable amount of characters
o Type – Accepts data with a certain data type
o Character – Accepts data without invalid characters
o Format – Accepts data that conforms to a specified
patter/format
o Presence – Requires data to be inputted
• Verification – Checking that data has been accurately
copied onto the computer or transferred from one part
of a computer system to another.
o Double entry – Data is entered twice and compared
o Visual/Screen – Manual check compared by the user
1.2 Pseudocode & Flowcharts
• Pseudocode - Verbal representation of an algorithm (a
process or set of steps) and flowcharts are a
diagrammatic representation.
• Sub-rountine - Block of code that can be called and
accessed by a main program.
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CIE IGCSE COMPUTER SCIENCE//0478
• Flowcharts
o CASE…OF…OTHERWISE…ENDCASE – Multiple
conditions and corresponding consequences
CASE OF [VARIABLE]
OPTION: [CONSEQUENCE]
OTHERWISE: [CONSEQUENCE]
ENDCASE
CASE OF GRADE
GRADE>80: OUTPUT “A”
GRADE>70: OUTPUT “B”
GRADE>60: OUTPUT “C”
OTHERWISE: OUTPUT “FAIL”
ENDCASE
• Input & Output (READ & PRINT) – Used to receive and
display data to the user respectively
FOR [VARIABLE]  [VALUE] TO [VALUE]
[CODE]
NEXT
OUTPUT “ENTER NAME”
INPUT NAME
OUTPUT “HELLO”, NAME
(ALTERNATIVELY)
PRINT “ENTER NAME”
READ NAME
PRINT “HELLO”, NAME
o REPEAT… UNTIL – Will run at least once till condition is
satisfied; Verification is done after running code
• Assignment - Each variable is assigned using a left arrow.
[VARIABLE]  [VALUE]
GRADE  98
• Conditional Statements:
o IF…THEN…ELSE…ENDIF – 1 condition
IF [CONDITION] THEN
[CONSEQUENCE]
ELSE
[CONSEQUENCE]
ENDIF
IF GRADE > 100 THEN
OUTPUT “INVALID”
ELSE
OUTPUT “VALID”
ENDIF
• Loop Structures:
o FOR…TO…NEXT- Will run for a determined/known
amount of times
REPEAT
[CODE]
UNTIL [CONDITION]
o WHILE…DO…ENDWHILE – May not ever run;
Verification is done before running code
WHILE [CONDITION] DO
[CODE]
ENDWHILE
2. PROGRAMMING
2.1 Programming Concepts
• Declaration & Usage of Variables & Constants
o Variable – Store of data which changes during
execution of the program (due to user input)
o Constant – Store of data that remains the same during
the execution of the program
PAGE 3 OF 5
CIE IGCSE COMPUTER SCIENCE//0478
• Basic Data Types
o Integer – Whole Number e.g. 2; 8; 100
o Real – Decimal Number e.g. 7.00; 5.64
o Char – Single Character e.g. a; Y
o String – Multiple Characters (Text) e.g. ZNotes; COOL
o Boolean – Only 2 Values e.g. True/False; Yes/No; 0/1
3.2 Primary Key
• It is a field that uniquely identifies each record. E.g.
Student code will be the primary key in a school
database.
DECLARE [VAR/CONST] AS [DATA TYPE]
[VALUE]
• IMPORTANT CONCEPTS
o Sequence – Statements are executed in order. E.g.
Variables must first be declared, and then used.
o Selection – Allows data items to be picked according to
given criteria. E.g. Finding the highest/smallest value
o Repetition – Causes statements to be repeated (loops)
o Totaling – Used with repetition, to keep the total
updated. E.g.
BillTotal  BillTotal + ProductCost
o Counting – Used with repetition to increment the
counter by 1, each time the loop is repeated. E.g.
NumItems  NumItems + 1
3.3 Query-By-Example (QBE)
2.2 Data Structures; Arrays
• Declaration
DECLARE [NAME][1:n] AS [DATA TYPE]
DECLARE GRADE [1:18] AS REAL
• Use of FOR Loop to Read & Write
DECLARE GRADE [1:18] AS INTEGER
FOR I  1 To 18
OUTPUT “GRADE OF STUDENT”, I
INPUT/OUTPUT GRADE [I]
NEXT
• Field: Field Name
• Table: Table Name
• Sort: Ascending (A-Z) or Descending (Z-A)
• Show: Checked (Present) or Empty (Absent)
• Criteria:
TEXT
Criteria
Name
Written As
Function
3. DATABASES
Contains
3.1 Data types
Does Not
Contain
Like
(“*x*”)
Not like
(“*x*”)
Begins With
Like (“x*”)
Values beginning with x
Ends With
Like (“*x”)
Values ending with x
Comes After
>= “x”
Values that come before
x in alphabetical order
Comes
Before
<= “x”
Values that come after x
in alphabetical order
• The data type names are different in Access:
o Real – Number
o String – Text
o Boolean – Yes/No
PAGE 4 OF 5
Values that contain x
Values that do not
contain x
CIE IGCSE COMPUTER SCIENCE//0478
Criteria Name
Between
Less Than
Less Than or
Equal To
Greater Than
Greater Than
or Equal To
Criteria Name
Between
NUMBERS
Written As Function
Between
Values in the range
“x” and “y” between x and y
<x
Values smaller than x
Values smaller than or
<=x
equal to x
>x
Values larger than x
Values larger than or equal
>=x
to x
DATES
Written As
Between
“#mm/dd/yyyy#”
and
“#mm/dd/yyyy#”
Before
< “#mm/dd/yyyy#”
After
> “#mm/dd/yyyy#”
Today
=Date()
x Days Before
Today
<=Date()-x
Function
Dates between the
specified dates
Dates before a
certain date
Dates after a
certain date
Records containing
today’s date
Records containing
dates x or more
days in the past
PAGE 5 OF 5
CIE IGCSE BUSINESS STUDIES//0450
TABLE OF CONTENTS
2
CHAPTER 1
7
CHAPTER 2
13
CHAPTER 3
20
CHAPTER 4
24
CHAPTER 5
27
CHAPTER 6
Understanding business activity
People in business
Marketing
Operations management
Financial information and decisions
External influences on business activity
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CIE IGCSE BUSINESS STUDIES//0450
1. UNDERSTANDING BUSINESS ACTIVITY
1.1 Nature of Business Activity
• Needs: goods or services that we need in order to live
• Wants: goods or services which people would like to
have. But are not essential for living.
• People’s wants are unlimited (you will always want
something)
• There are unlimited wants but there are limited
resources to produce them
• Resources include: Land, Labour, Capital & Enterprise
• This creates scarcity.
• Scarcity: there are not enough products to fulfil the
wants of the population
• Since there are limited resources, we have to make
choices on what we want. This means that we will be
giving something up, this is the opportunity cost
• Opportunity cost: the thing we give up by choosing
another item. The next best alternative.
1.2 Specialisation
• Specialisation: when people and businesses focus on
what they are best at.
• Using specialised machinery, work is more efficient
• Being efficient keeps costs low, good for competition
• A specialised worker has higher living standards
• Division of labour is when production is split in different
tasks and each worker performs one of these tasks
Advantages
Disadvantages
Workers specialized in
Workers become bored of
certain task, increases
doing the same job.
efficiency
Efficiency might fall
Less time is wasted from
If a worker is absent, no
one workbench to
other worker can do the
another, more efficiency
job. Efficiency might fall
1.3 Purpose of Business Activity:
• Businesses combine scarce factors of production to
produce goods or services to satisfy people’s wants
• Factors of production:
o Land – all resources provided by nature (oil, metal)
o Labour – the no. of people to make the products
o Capital – the finance and equipment (machinery)
needed to make products
• Enterprise – the skill of the person who brings other
factors of production together to make goods
• A business also employs people as worker and pays
them wages to allow them to consume products as well
1.4 Added Value
• Added value is how much more a business sells a
product for than the total cost of materials
Added Value = selling price – total cost
• It is NOT the profit because added value does not
include the price to pay for labour, transport etc.
• To increase added value, a business can either:
o Increase the selling price of product, while keeping the
total cost of material the same
o Decrease the total cost of materials, while keeping the
selling price of the product the same.
1.5 Classification of Businesses
• Businesses can be put into three sectors:
• In developing countries, the primary sector employs
most of the work-force. This is because most people live
in rural areas and there is low demand for services
• In more developed countries, the secondary and tertiary
sector employ more workers
• In economically developed countries, the tertiary
(service) sector employs most people as they import
manufactured goods from other countries (tourism)
1.6 Mixed Economy
• Has both a private sector and a public sector.
Stage
What it does
Example
Extracts and uses the
Farming,
Primary
natural resources to
mining, forestry
produce raw materials
Takes the raw materials
Manufacturing
Secondary and converts them into
(car, food, etc.)
manufactured goods
Providing services to
Retail shops,
Tertiary
consumers and other
hotels, hospitals
sectors
• Private Sector: Businesses NOT owned by government,
will make own decisions on what and how to produce.
• Public Sector: Owned by the government. Government
will make decisions on what and how to produce (i.e.
healthcare, education, defence, public transport)
Page 2 of 30
CIE IGCSE BUSINESS STUDIES//0450
1.7 Enterprise, Business Growth & Size
• An entrepreneur is a person who organises, operates
and takes risk to make the business better
• Characteristics of entrepreneurs:
o Hard Working
o Optimistic
o Risk Takers
o Self-Confident
o Creative
o Innovative
o Effective Communicators o Independent
Advantages
Independent, able to
choose how to use time
and money
Able to put own ideas
into practice
May become successful
and very profitable if
business grows
Able to make use of
personal interests and
skills
Disadvantages
entrepreneurs will have to
put their own money into
the business.
many entrepreneur’s
businesses fail (risky)
Lack of knowledge and
experience in starting and
operating a business
Lost income from not being
employee for another
business (Opportunity cost)
1.8 Business Plans
• A business plan contains business objectives, important
details about the operations, finance, and the owners
• Business plans assist entrepreneurs because:
o It helps gain finance. banks will ask for a business plan
before agreeing to a loan or overdraft for the business
o It forces the entrepreneur to plan ahead carefully,
which reduces risk of the business failing.
• The main parts of a business plan include: name, type of
organization, business aim and forecast profit
1.9 Government Support for Start-Ups
• Governments encourage entrepreneurs to set up a
business because start-ups:
o Reduce unemployment, new businesses create jobs
o Increase competition, gives consumers more choice
o Increase output, economy benefits from increased
output of goods and services
o Can grow further and become large and important
businesses which pay government more taxes
• Governments may give support to entrepreneurs by:
o Business ideas & help, they set up support sessions
held by experienced business people
o Finance, they may lend loans at low interest rates or
grants if business starts up in places with high
unemployment rates.
o Governments provide grants for training employees to
make them more efficient and productive
o Governments allow entrepreneurs to use research
facilities in universities
1.10 Business Size
• There are several different measurements of business
size and they all have limitations:
Measurements
Limitations
Some businesses employ
The number of people
few people but produce
employed in the business
high output values
The value of output of the high level of output does
business
not mean business is big
different businesses sell
The value of sales
different products
(expensive and cheap)
The total value of capital
some companies may use
(money) invested into the
cheap labor giving low
business (capital
output with low-cost
employed)
equipment
1.11 Business Growth
• Some businesses want to grow because:
o Higher profits
o More status for owners and managers
o can benefit from Economies of Scale (lower costs)
o Larger share of its market, ‘big names'
1.12 Economies of Scale
• Economies of scale are the factors that lead to a
reduction in average costs as a business grows.
• Purchasing - when businesses buy in ‘bulk’ so they get
cheaper prices
• Marketing - targeting a larger audience, business
advertises its own product rather than having another
company doing it
• Financial - bigger businesses get better interest rates
from banks as they are less risk
Page 3 of 30
CIE IGCSE BUSINESS STUDIES//0450
• Managerial: Big businesses can afford specialist
managers
• Technical - Big businesses can afford specialist machines
to do more efficient work with less staff
• Businesses can either grow by:
o Internal Growth
o External Growth
• Internal Growth is when the business expands its
existing operations
• External Growth is when the business takes over or
merges with another business.
• There are three types of External Growth:
• Horizontal Integration – firm taking over/merging with
another firm in the same industry
o i.e. a paper company taking over another paper
company
• Vertical Integration – firm taking over/merging with
another firm in same industry but different stage of
production (there is forwards and backwards)
o i.e. paper manufacturing company taking over paper
selling company
• Conglomerate Merger - firm merging/taking over
another firm in a different industry. (also known as
‘diversification’)
o i.e. paper company taking over a food company
1.13 Problems with business growth
(Diseconomies of Scale)
• Diseconomies of scale are factors that lead to increase of
average costs as a business grows above a point.
• Poor communication - Bigger businesses are hard to
send and receive messages.
• Low Morale - Big businesses employ many people, some
workers feel unimportant as they cannot grow in
business, efficiency lowers.
• Slow decision making - Bigger businesses take longer to
make decisions to satisfy all of the audience
• Some businesses stay small because:
o Market size is small
o Owner’s objectives
o Type of industry
1.14 Why Businesses Fail
• Poor management – from lack of experience, poor
choice of managers (family business), bad decisions
• Failure to plan for change – businesses need to adapt
everchanging business environment. Must take risks.
• Poor money management – lack of money to pay
workers, suppliers, landlords, etc.
• Over-expansion – (diseconomies of scale), management
problems and finance
• Competition with other businesses – new businesses
are at more risk of failing than existing businesses.
• This is because start-ups have lack of money, resources,
poor planning & don’t have much research
1.15 Sole Trader
• A business owned by just one person. It’s the smallest
type of business. Can employ other people however.
o Useful for people who are setting up new business
o Do not need much capital to get business running
o Will be dealing mainly with the public
Advantages
Disadvantages
Easy to set up, do not
Capital is usually provided
require a lot of money to
by owner, hard to get
set up
capital to expand firm
They are their own boss,
They have unlimited
has the freedom to choose liability (responsible for
their own holidays, work
any debts of the business,
hours, prices, who to
bank can take away
employ
possessions to pay back)
Close relationship with
Business is likely to remain
customers
small
Does not have to share
No one to discuss business
profits
matters with
Does not have to give
They are unincorporated
information about the
(business has same
business
identity as the owner). So,
business ends when
owner dies
Page 4 of 30
CIE IGCSE BUSINESS STUDIES//0450
1.16 Partnerships
• A business in which 2 to 20 people agree to own it.
Usually small businesses but bigger than sole traders.
o Useful for people who want to form a business but
don’t want the legal complications
o Industries such as medicine or law where you are not
allowed to form a company
o Partners that know each other very well
• Requires a Partnership Agreement
Advantages
Disadvantages
Easy to set up, do not
Capital is usually provided
require a lot of money
by partners
More capital invested
Partners have unlimited
(more expansion)
liability
Partners are motivated
Partners can disagree on
because any losses are
decisions. If one of the
shared by the partners
partners is inefficient, they
all lose money
Responsibilities are shared They are unincorporated.
(focused on different parts If one of the partner dies,
of business)
the partnership ends
• Contents of Partnership Agreement:
o Amount of capital invested by all partners
o Tasks to be done by each partner
o The way profits are shared out
o How long partnership will last
o Arrangements for absence, retirement and how
partners could be let known
o Rules for shareholder meetings
o List of directors and their jobs
o Voting rights of shareholders
o Details of how accounts are recorded
• Memorandum of Association – must contain important
information about the company:
o Company name, address
o What the business does
o Number of shares to be sold
Advantages
Disadvantages
Shares can be sold to lots
Difficult to set up (legal
of people. More capital to formalities).
expand
Owners are able to keep
Shares are difficult
control of company as
transfer. Requires other
long as they don’t sell too shareholders to agree
many shares
All shareholders have
Accounts are less secret
limited liability (bank can
than other forms of
only take amount of
business
money invested)
Company continues after
Company cannot offer it
a shareholder dies
shares to the public
• Private Limited Companies are useful for family
businesses or businesses/partnerships where owners
want to expand more (as you can sell shares)
1.18 Public Limited Company (PLC)
1.17 Private Limited Company (LTD)
• An LTD is different from the other because it can sell
shares and it is an incorporated business.
• Company must be owned by at least 2 shareholders
o A shareholder buys shares of an LTD company which
represent part ownership of the company
o Dividend is the amount of profit each shareholder gets
• Shares are sold privately to friends and family
• Has separate identity from owners, incorporated, so
company accounts are separate from the owners’
• Must have: Articles of Association and Memorandum of
Association
• Article of Association – must contain the RULES in which
the company will be managed. Contains:
• A PLC is similar to LTD only the shares can be sold to the
public. It is the biggest type of business.
• Shareholders of PLCs may attend an Annual General
Meeting where they may vote for the board directors
Advantages (in addition
Disadvantages
to those in LTDs)
Opportunity to raise high
Difficult to set up (legal
capital sums
formalities) & accounts
are even more public
No restriction of buying,
Danger of business being
selling or transferring
taken over due to public
shares
shares
Selling shares to public is
expensive
• DON’T GET CONFUSED, Public Limited Companies are
NOT in the PUBLIC sector, they are in PRIVATE sector
Page 5 of 30
CIE IGCSE BUSINESS STUDIES//0450
1.19 Joint Venture
• A joint venture is when two or more businesses start a
project together sharing capital risks, and profits
Advantages
Disadvantages
Costs are shared, good for Profits have to be shared if
expensive projects
project is successful
Shared knowledge of two
Might have disagreements
businesses
over important decisions
Risks are shared
Different methods of
running business
• Usually these businesses have been nationalized (used
to be private sector but government bought it)
• Capital comes from taxes, by tax payer
1.23 Business Objectives
• A franchise is an agreement of a business based upon an
existing brand/business
• The franchisor is the main business/brand
• The franchisee is the individual to start up franchise
• In a franchise, the franchisor allows the franchisee to
trade under its name and see its products for a fee
• The franchisee pays an original fee to franchisor and a
percentage of its profit for the privilege
• Franchisor provides support, such as:
o Advertising
o Employee training
o Legal advice
o Financial advice
• Franchise agreements last 5 – 20 years, if franchisee
cancels the agreement early there may be large fines
• Business objectives are aims or targets a business works
towards
• Business objectives give clear target to managers and
employees and boosts the workers’ motivation
• Private sector business objectives:
o Business Survival - Adjust to business environment,
change price of products if necessary
o Generating profit – pay a return to owners or provide
finance to invest further in business
o Returns to shareholders - discourage shareholders
from selling their shares. Can be increased by
increasing profit or increasing the share price
o Growth of business – increase salaries, economies of
scale. only achieved if customers are satisfied with the
product
o Market Share – the proportion of the total market
sales by one business, gives good publicity, more
influence over suppliers and customers
o Service to community – provide jobs, support
disadvantaged groups in society, protect environment
1.21 Risk, Ownership & Limited Liability
1.24 Stakeholder objectives
• Risk - the uncertainty of profits or danger of loss, events
that could cause business to fail
• Ownership – who owns the business (partnership =
partners, LTDs and PLCs = the shareholders)
• The people with risk are usually the owners
• Liability – how much the shareholders of a company are
liable for the debts in the business
o Limited Liability – liability of shareholders is limited to
the amount of money they invested (PLC & LTD)
o Unlimited liability – owners of business are held
responsible for all the debts of the business (not just
their investment) (Sole trader & partnerships)
• A stakeholder is any person with a direct interest in the
performance of a business
• There are two types of stakeholder groups:
o Internal Stakeholders work/own the company
o External Stakeholders are outside of the business
Internal Stakeholders
External Stakeholders
Owners
Consumers
Managers
Government
Workers
Banks
• Each stakeholder group has different objectives for the
performance of the business
• Internal Stakeholder’s objectives are payments or
profits, they want business growth so value of
investment increases or they get higher status/power
• Customers objectives are reliable products, value for
money, good quality, good design and good service
1.20 Franchise
1.22 Public Sector
• The public sector includes every business owned by the
government.
• Businesses in the public sector are public services, i.e.
education, transport, hospitals, education and police
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• Government objectives include: money from taxes, will
employ more people, increase country’s output
• Banks objectives are to make profit out of loans
• Since different stakeholders have different objectives, it
may cause conflict, to try to please all the stakeholders
• For example: customers want cheap products but
workers want higher salaries.
• Therefore, managers have to compromise to decide
which objectives are best for the company
2. PEOPLE IN BUSINESS
•
It is very important for a business to have a wellmotivated workforce
The main reasons why people work:
o Money: to pay for the basic needs for life and
some wants
o Security: to know that you are safe (financially)
o Affiliation (Social needs): to feel part of a
group, meet people, make friends
o Self-importance (esteem): to feel that you are
important and that the job you do is important
o Job Satisfaction: to feel pleasure that you have
done a good job
• Motivation – the feeling that makes employees
want to work hard and effectively in a business
2.1.1 Key Motivational Theories
•
•
•
•
•
2.1 Motivating Workers
•
•
‘Maslow’s Hierarchy of Needs’ – a pyramid showing
the different types of needs and how some are more
important than others
Safe/security Needs – protection against danger &
poverty. Having fair treatment
(fulfilled by having job security)
Social Needs – friendship, belonging in a group
(fulfilled by having colleagues at work)
Esteem Needs – having status and recognition
(fulfilled by being recognised for good work)
Self-actualisation – achieving your full potential,
feeling that you have done a good job
(fulfilled by being promoted & being given more
responsibility)
Maslow’s theory also suggests that each level in the
hierarchy (starting from Physiological needs) needs to
be achieved before moving on to the next
•
F.W Taylor’s theory - “All individuals are motivated
by personal gain”
•
This means that if the workers are paid more, they will
work more effectively
By breaking down worker’s jobs into simple tasks, you
could calculate how much output they could do in a
day
Taylor’s theory focused mainly on factory workers,
since it is easy to work out their output done
Taylor’s idea was that if the workers produced this
target output, they would be paid more money
This idea led to big productivity gains in companies
that adopted this theory
Herzberg’s theory – humans have two sets of needs:
o Basic animal needs (called ‘Hygiene’)
o To be able to grow physiologically (called
‘Motivator’ needs)
•
•
•
•
•
‘Motivator’ Factors
•
•
•
•
Achievement
Recognition
Personal Growth
Advancement/
Promotion
• Work itself
•
Physiological Needs – food, rest, shelter
(fulfilled by receiving wages)
•
‘Hygiene’ Factors
•
•
•
•
Status
Security
Work Conditions
Relationship with boss
& subordinates
• Salary
Herzberg’s theory claims that the ‘Hygiene’ factors
must be satisfied, if not, it will demotivate workers
• Only after they are satisfied, can the ‘Motivator’
factors can act as motivators for employees
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•
2.1.2 Methods of Motivation
•
•
•
There are 3 Factors that motivate employees:
o Financial Rewards
o Non-Financial Rewards
o Job Satisfaction
Financial Rewards/Motivators include:
o Wages (payment for work, usually weekly)
o Time Rate (payment per hour, i.e. 10$/hour)
o Piece Rate (where workers are paid depending on
the quantity of products made). Has also BONUS
system for employees who produce more than the
set target.
o Salaries (payment for work, usually monthly)
Financial Rewards/Motivators include:
o Company Car
o Discounts of products
o Health care
o Children’s school paid for
o House is paid for
o Free trips abroad (holidays)
•
•
•
The benefits of an organisational chart are that it
shows how everybody is linked together in the
organisation, they know who to reach and how.
Each employee can also see their own position, who’s
authority they are under and who they have authority
over
It gives everyone a sense of belonging, motivates
them to move up the chain of command
There are two types of organisational structures of a
business:
o You can have a ‘tall’ structure, with a long chain of
command:
o
2.2 Organisation and Management
•
•
•
•
•
Organisational structure – the levels of management
and division of responsibilities within a company
Organisational structures show the chain of command
in a company
this is usually in the form of an Organisational Chart
Organisational Charts show a clear structure of the
business and make it easy to see which part of the
company does what
Example of Organisational Chart:
•
•
•
•
•
•
You can have a ‘wide’ structure, with a short chain
of command:
Chain of command – the structure in a business that
allows instructions to be passed down from a person
to another, below them in the command.
Subordinate – someone who is lower in rank, under
authority of a superior (manager)
Span of control – how many subordinates work
directly under a manager
Authority – someone that has recognised power to
make decisions and to delegate tasks
Delegation – the process of giving authority to a
subordinate to perform a task (instructions)
The advantages to have a short (and wide) structure
is that:
o Communication is faster and more accurate
o Top managers are more in touch with
subordinates because there are less levels
o wider span of control means employees feel
trusted and take more decisions by themselves
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•
•
•
•
In organisational charts, it is usually arranged in
department (finance, operations, etc)
Sometimes there is conflict between departments (i.e.
marketing wants to buy something but finance does
not think it is necessary)
The supervisors working in these departments are
Line managers – they have direct responsibility over
people below them in the organisational chart
You also have Staff Managers – which are specialists
in certain areas to provide support and information to
line managers
•
•
•
•
•
•
o makes employees feel trusted and important
However, some managers do not delegate tasks
They might be afraid the subordinates will fail and
manager wants to control everything
Manager might also feel threatened that subordinate
will do a better job than them
Delegation means that once the task is completed, the
manager will have less direct control
This means the trust for the workers is increased by
the manager
Therefore, there needs to be more trust in workers in
order to reduce control over them
2.2.3 Leadership Styles
•
•
2.2.2 Role of Management
•
•
•
•
•
All organisations have managers. Leaders, director,
executive are all different names, but they are all
managers
The functions of managers include:
o Planning – setting aims or targets
o Organising – delegating tasks. organising people
and resources effectively
o Co-ordinating – making sure departments work
well with each other and have good
communication
o Commanding – making sure the workers are
keeping to targets and deadlines. By guiding and
delegating tasks
o Controlling – measuring and evaluating work of
employees and verify they are on target
Managers often delegate tasks to employees, giving
them authority to complete that task.
However, if the employee does a bad job, the
manager must accept the responsibility for it
Delegation is important because:
o Managers cannot do every job by themselves
o managers can then measure the success of the
employees
o work becomes more interesting for subordinate,
increases their motivation
Leadership styles are the different approaches to deal
with people when with authority
There are THREE TYPES OF leadership styles:
o Autocratic Leader: where the manager expects to
be in charge of the business and expects to have
their orders followed with no questions asked
o Democratic Leader: where the manager allows
the subordinates to be involved in the decisionmaking process
o Laissez-Faire Leader: Where the manager makes
broad/general objectives for the employees and
leaves them to make their own decisions.
2.2.4 Trade Unions
•
•
•
•
Trade union – a group of workers that join together to
protect their interests
A trade union is a pressure group
Employees usually have the same interests (i.e. good
wages, pleasant work environment, etc)
If an employee wants to join a trade union, they must
pay a yearly subscription for the benefits
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•
Benefits from a trade union usually include:
o Improved conditions of employment (such as
wages, holidays, hours of work)
o Improved work environment (health & safety,
heating, noise)
o Advice/support if member thinks they have been
unfairly fired, mistreated, etc
•
•
•
2.3 Recruitment
•
•
•
•
•
•
Recruitment – the process from identifying that a
business needs to employ someone, to the point
where applications have arrived at the business
Recruitment is one of the roles of the Human
Resources department
Recruiting usually happens when an employee leaves
a job, a business is starting up, or it wants to expand
Recruitment process (for external recruitment):
1. A job analysis is done to identify the tasks and
responsibilities to be carried out by the new
employee
2. Once the details of the job are gathered, a job
description will be made, outlining these duties.
3. From the job description, a job specification is
created, which outlines the requirements,
qualifications and expertise for the job
4. Then the job is advertised in the appropriate
media (i.e. if it is a finance related job, it might be
advertised in finance magazine)
5. Candidates start sending their application forms
and the company does a short-list for interviews
(because they cannot interview all)
6. The candidate is chosen after the interviews by
the company, job is filled
There are two types of recruitment:
o External Recruitment – job is filled by someone
who is not an existing employee
o Internal Recruitment – job is filled by an existing
employee of the company.
Internal recruitment is good because it saves money
for business. The person already has knowledge about
the business & position and it motivates other
workers to get a promotion.
however, it doesn’t bring in new ideas & experience.
•
There are also two types of employment:
o Part-time employment
o Full-time employment
Part time employment is normally between 1 and 35
hours a week
Advantages:
o Work hours are flexible. Fits with employees that
have kids to take care of
o Business can extend the opening/closing hours
o Employees can just work at busy times
o Cheaper for the employer than employing a fulltime worker
Disadvantages:
o Employees are less likely to be trained because
they might see it as temporary and don’t want a
promotion
o Takes longer to recruit many part-time workers
than a couple full-time workers
o Might be less committed to the company
2.3.2 Training
•
Training is important for a business because:
o It helps employees become more comfortable
with new processes or equipment
o Improves the efficiency of the workers
o Makes employees more valuable to the company
because they become more skilled
o Reduces the amount of supervision needed by
the workers
o Reduces the amount of accidents
•
There are three types of training:
1. Induction Training – where the employee is given
an introduction on the company’s procedures and
customs, and is introduced to their co-workers
Advantages
• Employees settle into
their job quickly
• Workers make fewer
mistakes
• May be a legal
requirement
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Disadvantages
• Time consuming
• Worker is being paid
while not doing work
• Delays the start of work
for the employee
CIE IGCSE BUSINESS STUDIES//0450
2. On-the-job Training – where the employee does
the job while being supervised by a more
experienced worker, giving tips, suggestions and
help
Advantages
• Employee does not need
to be sent away
So cheaper than off-thejob training
• There is still production
from worker while
training
• Employee is trained
exactly how the
company want
Disadvantages
• Trainer won’t be as
productive because
they are teaching
employee
• Trainer might have bad
habits and pass on to
employee
• Not recognised training
qualifications outside
the business
3. Off-the-job training – where the employee is
trained away from the workplace, normally by
specialised trainers.
•
•
•
•
•
•
•
Advantages
Lots of skills are taught
trainings are sometimes
off-work hours, worker
will still work
Employees become
versatile (can be moved
around company and
know what to do)
Employees are taught by
expert trainers. Up-todate knowledge
Disadvantages
• Expensive to send
employees off to expert
trainings
• Workers are being paid
but not doing any work
• Professional training
gives employees
additional
qualifications, makes it
easier for employee to
find another job
Sometimes, a company might need to reduce the size
of the workforce, possibly because of:
o Automation (robots replacing human jobs)
o Less demand for products or services
o Business might have relocated abroad
o Business being taken over/merged and now there
are too many workers doing same job
Companies need to think ahead on the future and
establish how many employees they will need and
their skills, this is called workforce planning
When a business needs to reduce the number of
employees, they can either dismiss the employee or
make them redundant
•
•
Dismissal – when the worker is told to leave the job
due to poor work or poor behaviour (i.e. if employee
is always late for work after being given warnings,
when employee is caught stealing, etc)
It is more commonly known as being ‘fired’
Redundancy – when a business no longer needs an
employee. Even though the employee did nothing
wrong.
Usually happens during period of falling sales or due
to an economic recession (when no one is buying
anything)
2.3.4 Legal Controls over employment issues
•
•
•
•
There are many laws in countries, that ensure that
everyone has equal employment opportunities
regardless of race, gender, religion, age etc.
This means that businesses need to be careful when
advertising a job. They cannot advertise for just a
single type of person.
Companies must treat all applicants for the job
equally, if not, they will be fined and prosecuted
Employees of a business have legal right that must be
protected, which includes:
o Unfair discrimination at work/when applying: i.e.
when employers discriminate unfairly against
employees or applicants due to their race, gender,
religion or colour.
o Health and safety: there are laws that make sure
that employees are protected from dangerous
machinery, that they are provided safety
equipment & clothing, hygiene conditions,
suitable temperatures, provide breaks.
o Unfair dismissal: when the worker is dismissed
unfairly (i.e. from joining a trade union, being
pregnant, or when given no warnings before being
dismissed), the worker can take their case to an
industrial tribunal to see both sides of argument.
o Wage protection: an employee in a business
should have a contract of employment, where it
should contain the wage rate, frequency of wages
and what deductions are made from the wages
(from tax). In some countries businesses pay
whatever they want because unemployment is
high, so they offer very low wages.
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• Message is reinforced
by the speaker’s body
language
Governments take action by creating a legal
minimum wage.
2.4 Internal & External Communication
•
•
•
•
•
•
•
•
•
•
•
•
•
Effective communication is important so that the
information sent in the message is received,
understood and acted upon as it should
It is important to businesses because if it is not
understood, it can lead to serious consequences
There are two types of communication in businesses:
Internal Communication – communication between
employees of the same business
External Communication – communication between
the business and other businesses and individuals
External communication has to be especially efficient
because it establishes the image and the efficiency of
a business
i.e. if a company communicates inefficiently with their
suppliers, they might receive the incorrect materials
Effective communication involves:
1. The transmitter/sender sending a message to pass
on information
2. A medium of communication – the method for
sending message (i.e. e-mail, phone, etc)
3. The message being sent to the receiver
4. The receiver confirming that the message has
been received and responds to it (feedback)
There are two types of communication:
o One-way communication – where the receiver
cannot reply to the message (i.e. posters)
o Two-way communication – where the receiver
can respond to the message, could be just
confirmation that message was received (e-mail)
The methods of communication include:
Verbal methods – sender speaks to the receiver (i.e.
meetings, telephone, video conference)
Advantages
Disadvantages
Information given out
• If talking to many people,
quickly &Efficient way
it’s hard to tell whether
to communicate with
everyone got the
many people
message
Opportunity for
• Not good for accurate
immediate feedback
messages and if a
•
•
•
•
•
•
permanent record of the
message is needed
Written methods – sender creates e-mails, memos or
letters, including the use of Information Technology
Advantages
Disadvantages
Message can be
• Might lead to too many
referred to in the future
e-mails and ‘information
“hard evidence”
overload’
Easy to explain
• Two-way communication
complicated messages
is difficult
Can be copied and re• Hard to check if message
sent to many people
has been received
Quick and cheap
• No body language to
emphasize message
Visual methods – sender uses diagrams, charts,
videos, PowerPoints
Advantages
Disadvantages
• Information presented
• No feedback and needs
in more appealing way,
other methods of
people will be more
communication to go
interested to look at it
with it
• Can be used to make
• Graphs and charts may
written messages
be difficult for people to
clearer, to illustrate the
understand, message
point
may be misunderstood
2.4.2 Communication Barriers
•
•
•
•
•
Communication Barriers – things that prevent
efficient communication
Problems with the sender: when language is too
difficult, speaks too quickly/not clearly, communicates
wrong message
Overcome by: using understandable language, making
sure message is a clear as possible by asking questions
to make sure message was understood
Problems with the medium: message may be lost/not
seen by receiver, wrong medium used (i.e. important
message on noticeboard), if message is being passed
along – it might get distorted
Overcome by: sender asking for feedback/receiver
always sending feedback that message is received,
selecting the appropriate channel to send message
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•
•
Problems with the receiver: not listening/paying
attention, receiver doesn’t trust the sender/doesn’t
want to do it
Overcome by: emphasizing importance of message,
ask for feedback to ensure it was understood, using
direct communication
3. MARKETING
3.1. Marketing, Competition & Customer
• Marketing – Identifying customer needs and satisfying
them
• There are many departments within the Marketing
sector of a business
• The role of the marketing is to:
o Identify customer needs – this will be done via
‘Market Research’. It will influence the development
of a product, its price, and the sales technique
▪ A good marketing department should also be
able to anticipate (predict before happening)
changes of customer needs (i.e. due to
advancement in technology)
▪ Find new trends or gaps in market with potential
o Satisfy customer needs – selling the exact product
customers want, for a price they are willing to pay
o Maintaining customer loyalty – building customer
relationships and make sure that existing customers
will continue to buy from them and to attract new
customers
▪ Maintaining customer loyalty will be achieved by
always satisfying customer needs
• Markets don’t stay the same forever, businesses need to
adapt to market changes in order to stay competitive
• Some markets change very often (i.e. phones) while
some don’t change quickly (i.e. jewelry or cereals)
• Markets change because consumer spending patterns
change, this might be due to:
o Trends and fashions change – for a period of time it
might be fashionable to have a specific product (i.e.
Fidget Spinner) but a month later no one buys them
o Advancement in technology – new products provide
the latest technology so older versions (i.e. iPads or
computers) don’t have high sales
o Unemployment/Wages – Economies with high
unemployment rates/low wages will not have high
sales of expensive products
o Ageing population – different ages are interested in
different products (i.e. anti-ageing creams)
• Changing customer needs are important to businesses.
They must identify these changes and respond in order
to stay successful
• Market Share – the percentage of the total sales of a
market held by a single business (i.e. if Company A has
$50 Million in sales out of a $200 Million market, then
Company A has (50/200 =) 25% market share
• Some markets have become more competitive because:
o Globalization – products are sold all over the world
o Transportation – it is cheaper, quicker and easier to
send products around the world now
o Internet – customers can now search for products or
services and buy from somewhere else around world
• For a business to stay competitive, it must:
o Maintain good customer relationships
o Keep improving its existing products
o Bring out new products to keep customer’s interest
o Keep costs low
3.1.3 Market
• Market – the total number of customers, potential
customers and other sellers of a product/service
• There are two types of market:
o Mass market – where there is a very large number of
sales of a product type
o Niche market – a SMALL (usually specialized)
segment (part) of a mass market
• For example, the tie industry is a mass market, but a
business that makes ties out of crocodile skin is a niche
market
MASS Market:
Advantages
Disadvantages
• Sales are very high
• Lots of competition
• Can benefit from
• High costs of
economies of scale
advertisement
• Opportunities for growth • Many similar products
(large sales)
so it may not meet
specific needs of all
• There are many
customers
variations of products
so risk is spread
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NICHE Market:
Advantages
• Avoid competition with
big businesses
• Specific needs of
customers are focused.
Advantage over mass
market
Disadvantages
• Small – limited number
of sales
• Usually specialize in just
one product, if product
has low demand, it will
fail
3.1.4 Market Segmentation
• Market segments – a sub-group of a market in which the
consumers have similar characteristics or preferences
• A market can be segmented by:
o According to age
o SOCIO-ECONOMIC group – grouping people
according to how much they are paid
o Location – where people live (people that live in wet
areas will buy more waterproof clothing than those
who live in dry areas)
o Gender – men and women products differ
o Lifestyle – how many children a person has, religion,
habits, etc.
• Benefits of market segmentation:
o Business aims all of its marketing efforts to the
specific segment, making marketing costs efficient
o Since less money is spent on marketing, more profit
o Identify a market segment whose needs are not
being fully met and fill the gap (first in market)
3.2 Market Research
• There are 2 types of businesses:
o Product-oriented business – a business that focuses
mainly on the product itself
o Market-oriented business – a business that focuses
on market research and find out what the customer
wants BEFORE a product is developed
• Market research is important because a business needs
to know how many people would be willing to buy the
product, this is to see how profitable it would be
• Market Research – gathering information about
consumers' needs or preferences in a market
• There are 2 main types of market research:
o PRIMARY RESEARCH (field research)
o SECONDARY RESEARCH (desk research)
• Primary Research - Gathering of ORIGINAL data by
talking directly with customers/potential customers
• Primary research includes:
o Questionnaires/surveys
o Interviews – person will interview other person and
ask questions
o Samples – A group of people who are selected
(randomly) to answer (i.e. questionnaire)
o Quota Sample – when people are selected based on
certain characteristics (age, income)
o Focus Groups – a group of people who represent the
target market. They test out product/service and
explain what they like or don’t like about it
o Observations – many methods, i.e. Seeing which
television channels are being watched or watching
people and their habits or seeing which products have
sold well in a store
Benefits
Limitations
• Detailed information
• If questions in
can be gathered about
questionnaires aren’t
the product (can even
thought out answers
be carried online
won’t be useful to the
business
• Customer/potential
customer’s opinions
• Can take lots of time
can be gathered and it
and therefore,
is detailed
expensive
• Most of these ways are • Interviewer may lead
inexpensive and gather
the interviewee to
lots of useful data
answer in a certain way
(inaccurate)
• Secondary Research – information that has already been
collected and is available for others
• This information can be obtained either from INTERNAL
SOURCES or EXTERNAL SOURCES.
• Internal Sources – within the firm’s own records: sales
departments, customer records, finance department and
CUSTOMER SERVICE department
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• External Sources – outside the business: government
statistics (i.e. population, ages), Newspapers, Market
research agencies, INTERNET
Benefits
• cheaper than primary as
research has already
been done by others
• There is some
information (i.e.
economic forecasts or
population size) that
can’t be obtained by
primary research
Limitations
• You do not get specific
results for a certain
product or service, you
get broad results
• data may be outdated
or incorrect as it was
collected by others
• Might not have the
specific information
• Regardless on which type of research a business chooses
to use, the accuracy of the research data depends on:
o How carefully the sample was drawn up
o How the questions in questionnaires/interviews
were written to make sure honest answers were
given
o The sample itself and its size. By using quota
sampling you might get more reliable results
o The bias – some secondary research will be biased
(i.e. articles on newspapers) which means the
information might be unreliable
o Age of the data – older data might be inaccurate
3.3 Marketing Mix
• Marketing Mix – all of the activities that are involved
when marketing a product or service
• The marketing mix can be summed up as the 4 Ps:
o Product
o Price
o Place
o Promotion
You should always mention the 4 Ps when
answering question about Marketing Mix!
3.3.1 Product
• The product itself is part of the marketing mix, it has to
ensure it is the right product for the market.
• This includes the quality and the design of the product
(including its packaging)
• Marketers must ask themselves “what can I do to make
this product better than my competitors’ products”
• Unique Selling Point (USP) – the special feature of a
product that makes it different from other products
• When businesses are developing new products there are
several benefits, but also many costs/implications:
Benefits
Costs
• Since the product has
• Carrying out new market
its USP, the business
research & analysis is
will be the first into the
expensive
market with the new
• Producing prototypes &
product
cost of wasted materials
• Diversification for the
• Lack of sales if the target
business – more range
market is wrong
of products to sell,
• Deterioration of brand
more customers
image if the new product
• Allows business to
fails to meet consumer
needs.
expand into new (or
existing) markets
• Now-a-days products are sent straight to a retail store.
There is no seller to persuade the potential customer to
buy the brand’s product over competitors
• This has to be done through brand image of the product
• Brand image – the identity of a product which separates
it from competitor products
• The product brand is advertised to inform all the
qualities about the product and encourage consumers
• Businesses want to encourage existing and
new/potential customers to buy from them and create
Brand Loyalty
• If a business has a bad brand image due to poor quality
or bad service, then consumers will not buy from them
and there won’t be brand loyalty.
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CIE IGCSE BUSINESS STUDIES//0450
• The other very important aspect of the product is the
packaging. It has 2 functions:
o To be easy to put the product in, protect it, allow it to
be used easily, and to be easily transported from
factory
o To promote the product: it must appeal to the
customer (colour & shape) and must emphasize the
brand image (i.e. a luxury product’s packaging might be
gold colour)
• Product Life-Cycle – the stages a product will go through
all the way from development until decline (stop selling)
1. Development of product – market research carried
out and product is tested, before launching (no
sales)
2. Product introduced to market – Sales growing
slowly because customers don’t know it exists yet
(no profit)
3. Growth - Sales grow quickly – advertising is changed
to encourage customer loyalty
4. Maturity - Sales still increase, but slowly,
competition is high so prices are changed (profits
are at highest)
5. Saturation – competition is very high, profits start
to fall as sales reached maximum point. Price
reduced
6. Sales decline – new products are made or trend is
gone. Prices are so low it is unprofitable to make it.
Advertisement is stopped
• As you can see different stages can influence marketing
decisions (i.e. pricing & promotion)
3.3.2 Pricing:
• There are 5 main types of pricing methods:
o Cost Plus – the cost of manufacturing plus a profit.
it will cover costs and make sure profit will be made
o Competitive – priced just below the competitors’
prices to get more market share and increase sales
o Penetration – priced lower than competitors’ prices to
enter new market (consumers will try out cheaper
product and see if they like it)
o Price Skimming – a high price is set for a new product
on the market. (used for new inventions or
development of an old product) high profits to cover
the research
o Promotional – priced very low for a short period of
time to increase sales. when there is lots of stock but
no one is buying. don’t make much (if any) profit
Method
Benefits
Limitations
• It is easy to
• You could lose
create and apply
sales if price is
Cost Plus
too high
compared to
competitors
• Lots of sales
• You have to do
because the
research to see
price is
what
reasonable
competitors’
Competitive
prices are. Time &
• Product is not
Money
under- or overpriced
• Prices are low so
not much profit
• Sales are
• Product is sold at
guaranteed and
low price so profit
Penetration
the new product
will be low
enters a market
• Establishes
• Price is so high
product as good
that may put off
Price
quality
potential
Skimming
customers off
• Make quite a lot
of profit
• Gets rid of
• there will not be
unwanted stock
much/if any
that won’t sell
profit made –
because sales
• renews
Promotional
revenue is lower
consumer’s
interest in
business if sales
are falling
• Price Elasticity – a measurement of how responsive the
market is when there is a change in price of a product
• In other words, how much you can increase the price
before sales fall enough that you make less money
• A product either has price-elastic demand or price
inelastic demand.
• Price-Elastic Demand is when the % of the loss in
demand is GREATER than the % of the increase in price
• i.e. prices increase by 5% but then sales decrease by
10%. Therefore, there is falling revenue for the business
• Price-Inelastic Demand is when the % of the loss in
demand is LESS than the % of the change in price
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• This means you can increase the price of the product a
lot without the demand changing (i.e. oil & petrol
because people have to buy it)
3.3.3 Place – Distribution Channels
• Where a product is sold will affect how well it will sell
• Distribution Channel - the method a business will use to
send a product from the factory to customer/retailer
There are 4 main distribution channels:
1. Manufacturer sells products directly to consumer
(i.e. car components to car factory)
Advantages
Disadvantages
• Reduces storage costs for • More expensive to
small retailers because
buy from wholesaler
small quantities are sold
than from
manufacturer
• Small quantities so
transport costs are low
• Wholesaler might not
have all the products
• Wholesaler can give
a retailer wants
feedback on what sells
well to producer
• Takes longer to get to
consumer
2. a manufacturer hires an agent (person or business)
Advantages
Disadvantages
that will sell products on behalf or manufacturer
• Very simple
• Impractical because
Advantages
Disadvantages
• Suitable for products that consumers don’t usually
• Agents know the most
• Manufacturer loses
live near factories
are sold straight out of
profitable places & prices lots of control on
factories
• Not good for products that
to sell in other markets
the way the product
can’t be sent easily by post
• There is a lower price for
that manufacturers may
is sold to customers
(may be expensive to ship
consumer (cuts retailer)
not know
it)
• Producer sells to retailers which sell to consumers:
3.3.4 Promotion
(i.e. farms selling food to big supermarkets)
• Promotion – publicizing a product/brand to increase
• Advantages
• Disadvantages
customer awareness or increase sales
• Manufacturer sells lots
• There is no direct
• The aims of promotion include:
of stock to retailer
contact with
o To create a brand image for a product
customers which
• Cheaper transportation
o To introduce a new product into a market
makes It hard to
costs because all
o To increase competition in a market
create customer
products go to one
o To improve the company’s image
loyalty
place
o To increase the sales of a product
• There are many types of promotion methods a business
may choose to use.
• There are 2 types of advertisements:
o Informative Advertisement – where the promotion of
a product focuses on giving information about a
• Producers sell to wholesalers – which buy in bulk and
product (i.e. the benefits of the product)
then divide their stock into smaller quantities and sell
o Persuasive Advertisement – where the promotion of a
them to retailers
product focuses on persuading the consumer that they
really need the product and they should buy it
• A business must also choose the most suitable
advertising media to use to promote a product/brand
• Advertising media include:
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o Television – suitable for products sold to most people
(food, cars, household products). it is very expensive
but millions of people will see it
o Radio – cheaper than TV but there’s no visual message
o Newspapers – suitable for local products. Cheap to
advertise and can be select to target specific group
o Magazines – niche/specialist products can be
promoted in specific magazines (bike magazines,
technology)
o Billboards – suitable for mass products/local events.
Reasonably cheap and are seen by many people. But
many people miss it. And no detailed info can be put
o Internet (social media) – suitable for products people
already know (clothes, books, electronics). Quite cheap
and through algorithms, websites can direct ads to a
target audience, and orders can be made online.
However, there is lots of competition (i.e. top on
google)
• Another way a business can promote a product/brand is
through Sales Promotions – when incentives (i.e. special
offers/sales) are used to increase sales (short term)
• The main sales production methods include:
o Sales (price reductions)
o Gifts (i.e. little toys in cereals)
o “Buy one get one free”
o Competitions (I.e. raffles, a chance to win something)
o Free samples
• When a marketing department of a business is deciding
which type of promotion it should use, it must take into
account the marketing budget – the financial plan for
marketing product/brand for a period of time
• i.e. if the budget is small, a business cannot afford to
advertise on television
• It must plan out perfectly in order to have cost
effectiveness, while reaching target audience
• This is where small business struggle compared to big
businesses, because their budget is so much smaller.
3.3.5 Technology & Marketing Mix
• Now-a-days most things are sold on the internet, when
you buy or sell goods/services on the internet it is called
E-Commerce
• Not every product/service is suitable for e-commerce,
products that are handmade (i.e. suits) or businesses
that like a personal approach with customers
• The opportunities and threats of e-commerce to a
BUSINESS include:
Opportunities
Threats
• Low-cost promotion:
• Competition is very high
websites are cheap to run because competitors also
and can promote worldhave websites to sell
wide
• Website design must be
• Everything can be
easy to use and attractive,
automated (orders are
this costs money
received and sent to
• Transport costs per
warehouse to dispatch)
product sold are higher
• Businesses can buy from
than sending all to retailer
other businesses
• No direct contact with
(materials/supplies)
customers – less feedback
• Opportunities & threats of e-commerce to consumers:
Opportunities
Threats
• Don’t need to leave house • Need access to internet
to buy products, shipped
(poorer countries don’t
straight home
have good access to web)
• Easy to compare different • slow servers or websites
prices from different
or computer failures can
stores and buy cheapest
frustrate customers
• Payment is very easy
• products cannot be
through credit/debit card
seen/touched/tried on
(i.e. shoes) and returning
• Can view and buy
products is inconvenient
products from abroad,
would be impossible
• Some people are worried
without
about identity theft or
credit card fraud by
• Competition of eentering their details onto
commerce makes prices
a website
much cheaper for
consumers
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3.4 Marketing Strategy
• Marketing Strategy is the plan of action to promote and
sell a product or service
• This includes combining the 4 elements of the marketing
mix (Product, Place, Price, Promotion) to achieve a
marketing objective, which could include:
o Increasing the sales:
▪ Of existing products (i.e. by selling in new
market)
▪ Of a new product
o Increase market share/maintain market share
• The different elements of the marketing mix are very
important to influence customer decisions.
• For example: A product is made, priced reasonably, and
meets the consumer needs, but there is no promotional
element. No one will buy it because people don’t know
about its existence
• Or if a product is made that doesn’t meet consumer
needs, so it won’t sell regardless of the price set
• It is crucial to have all elements working together in
order to influence consumer decisions (buying the
product)
3.4.2 Legal Controls in Marketing
• There are many laws in different countries to protect
consumers from businesses taking advantage of their
lack of knowledge or lack product information
• These legal controls include (in the U.K.):
o Businesses are not allowed to sell products that
weigh less than they should, or if weighing
equipment is inaccurate
o ‘Trade Descriptions’ - Businesses are not allowed to
give consumers misleading information on purpose
(i.e. saying that a shirt is made out of silk when it is
made out of cotton)
o ‘Sale of Goods’ - Businesses are not allowed to sell
products that have less-than-satisfactory quality –
that don’t fit for the purpose intended (i.e.
waterproof shoes that aren’t waterproof)
o A service must be provided with at-least
satisfactory skill and care
o Businesses cannot have misleading pricing claims
(i.e. 50% off today, when yesterday it was the same
price)
o A business is responsible for any damage/harm that
a faulty (or dangerous) product might do to a
consumer
o Customers have 7 days in which they can change
their minds about purchasing a good or service. This
applies to any transaction made over distance (i.e.
online)
3.4.3 Entering New Markets Abroad
• The globalization of businesses has been increasing over
the years, there are opportunities & problems to this:
Opportunities
Problems
• Growth potential in other • Lack of knowledge of
countries: countries are
competitors or consumer
developing and population habits
incomes are increasing
• Cultural differences: for
• Markets in original country example, alcohol won’t
might be saturated (sales
sell well in middle east
are low)
• Exchange rates: in some
• Can produce products in
countries their currency
abroad and learn about its
isn’t stable so price of
market to increase sales
importing goods increase
• Trade barriers are lowered • Transport costs are more
in most countries so it is
expensive
cheaper to enter markets
• However, there are many methods to reduce and
overcome the problems of entering a new market:
Problem
Method to overcome
Joint-Ventures: by working
together/merging with local businesses
Lack of
in the same market, a business will gain
knowledge a lot of important knowledge about the
(& Cultural culture & market
Differences) Franchising: letting people from the
market abroad which have local
knowledge to choose location of shop
Licensing: the business gives permission
Transport
for a local business to sell goods under
costs are
its name, so they do not have to
expensive
physically import all the products
Localizing Existing Brands: where a
business still has the same brand image
Cultural
but adapts it to the market it is in (i.e.
Differences
McDonalds cooking vegetarian meals in
India)
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4. OPERATIONS MANAGEMENT
4.1 Production of Goods and Services
o More output compared to inputs
o Lower costs per unit (AKA Average cost)
o If there is more output, maybe less workers needed,
less people to pay wages
o If there are less people working, raising their wages
will increase motivation and so productivity
• Businesses hold inventories/Stock to ensure that there
are always enough products to satisfy demand of
customers
• If a business doesn’t have enough stock of a product it
might lead to lower sales
• When the inventories get to the ‘reorder point’, they will
be reordered to get stock back up to maximum point.
• Types of waste that occur in production:
o Overproduction → leads to high storage costs and
possible damage to goods while in storage
o When nothing is happening to the goods (not being
processed or moving) this is Waste
o Transportation – when the goods are being moved
unnecessarily → fuel price, may get damaged
o Motion – any action made by an employee that does
not relate with the production of goods wastes time
o Over-processing – when sophisticated machines are
being used to do simple tasks
o Defects – when goods have faults/defects that
require them being inspected/fixed wastes time
• Lean Production – the techniques used by businesses to
reduce waste, therefore increasing efficiency.
• 3 Types of Lean Production:
o Kaizen
o Just-In-Time inventory (JIT)
o Cell Production
• Kaizen – Japanese Term. Means “continuous
improvement” by focusing on constantly reducing waste
• The Kaizen technique involves workers meeting regularly
to discuss problems and to find solutions
• Just-In-Time – a production method that virtually
eliminated the need of having inventories of raw
materials for production and of finished products
• JIT method involves an efficient system to time
specifically when the raw materials should arrive at a
factory, for production, and when a truck should arrive
to carry the finished products to the next stage of
production. (used by Volkswagen)
• Production – the making of a product or service to
satisfy consumer wants and needs
• A business combines the inputs/economic
resources/factors of production to produce a more
valuable output (this could be a good or a service)
• The ‘inputs’ include:
o Land – For factories or for materials
o Labour – Employees
o Capital – Money/finance
o Enterprise – Managers
• Businesses want to combine all of these inputs efficiently
to keep costs low to increase profits
• Labour-Intensive Production – where lots of workers are
used rather than machines to make goods. Usually done
in countries with low wages so that it is more efficient.
• Capital-Intensive Production – where businesses use
machines/robots rather than workers. Usually done in
developed countries where the wages are high.
• Productivity – the output (goods) measured against the
inputs (resources) to create it
Productivity = Quantity of Output / Quantity of Inputs
• The difference between Production and Productivity is
that Production is the process of creating the
product/service from inputs. And the Productivity
measures the efficiency of the Production
• Businesses usually measure the productivity by
measuring one of the factors of production against the
outputs (usually Labour)
Labour Productivity = Output / No. of employees
• Efficiency is increased by either:
o Using fewer input to produce the same output
o Using the same inputs to produce higher output
• How to increase productivity/efficiency:
o Improving the layout of machines to reduce wasted
time moving from one workspace to another
o Improving the labour skills of workers so they use
more productive techniques (more efficient)
o improving employee motivation
o Introducing new technology (i.e. automation)
o Improved quality control (check if product is not
faulty) to reduce wasted time checking
• Benefits of increasing efficiency:
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• Just-in-time system reduces costs by not holding any
inventory. Because components and materials arrive
just-in-time when needed.
• Cell Production – where production is divided into
separate units (cells) each making a part of the finished
product. Rather than having a flow or mass production.
• Cell Production improves employee morale so they work
harder and more efficient.
4.1.2 Methods of Production
• 3 main methods of production:
o Job Production – products made one at a time
o Batch Production – a quantity (batch) of a product is
made, then a batch of another product is made
o Flow Production (mass) –large quantity of products
made in a continuous process
• Job Production:
Features
Products are
made specifically
to order
Each order is
different
i.e. bridges, ships,
cinema films,
suits
• Batch Production:
Features
Similar products
are made in
batches
i.e. bakery:
makes one type
of bread, then
one type cake.
Furniture,
clothing
Benefits
good for “oneoff” products
meets exact
requirements
of customer
varied work
increases
employee
motivation
Benefits
Flexible work,
can change
products easily
Gives some
variety to
worker’s jobs
More variety =
more consumer
choice
Limitations
Often labor
intensive, + cost
Production
takes longer
Any errors are
expensive to fix,
(made to order)
Materials are
more expensive
Limitations
Machines must
be reset to do
diff. batches
Semi-finished
products may
need to be
transported
around (+ cost)
Need space for
stocks of raw
material
• Flow Production:
Features
Large quantities
of a product are
produced
Ingredients start
at one end &
flow to the
other end,
ready to be sold
Cars, drinks,
electronics, any
mass-made
products are
made this way
Benefits
High output,
capital intensive
more efficient
Costs are low
Benefits from
economies of
scale
Works 24/7, no
need for labor
No need for
moving goods
around (all
made in the
same place)
Limitations
Very boring for
employees
High cost of
inventory of
output & raw
materials
Costs of setting
up are very high
If machine
breaks down,
whole
production
stops
• Automation – when equipment in factory is controlled
by a computer to do mechanical processes (i.e. painting
car). Only workers are to ensure it runs smoothly
• Mechanisation – when production is done by machines
but operated by people. Used to do difficult, precise or
dangerous tasks. Work 24/7.
• Computer Aided Design (CAD) – software that helps
design or re-style products quickly, allows technical
sketches to be very detailed
• Computer Aided Manufacture (CAM) – when computers
monitor production and control machines/robots
• Computer Integrated Manufacturing (CIM) – wen
software that designs the products is integrated with the
machines that produce (CAM + CAD)
4.2 Costs and Scale of Production
• Fixed (overhead) Costs – Costs that do not change with
the number of items sold/produced.
• Fixed costs must be paid regardless if the business is
making a profit or not.
• Examples of Fixed Costs:
o Rent of factory: even if you produce lots of products,
the rent price will be the same
o Insurance: you set the insurance cost before-hand
o Bank fees: bank fees are a set price, they don’t
change depending on the products produced
o Management Salaries: they are set regardless of
production
o Staff cost (Security)
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• Variable Costs – costs that are directly proportional with
the number of items sold/produced.
• The more items produced, the higher the variable cost
• Examples of Variable Cost:
o Raw materials: the more you produce, the more
materials you need
o Electricity & Gas: Energy is paid by use. if you are
producing more, more electricity is being used
o Shipping cost: Making more products means you have
to ship more items and shipping is paid by weight
• Total Cost – Fixed and variable costs combined
• Average Cost (Per Unit) – total cost of production
divided by the total output. Referred to as Unit Cost
• Large businesses can benefit from Economies of scale
and therefore getting lower average costs.
4.2.3 Break-Even Charts
• Break even charts show how costs and revenues of a
business change with sales. They show the level of sales
the business must make in order to break even
• The break-even point is where:
total cost = sales revenue
Where the revenue line intersects the total cost
• Sales revenue is the income of a business from sales of
goods or services in a period of time.
• To draw a break-even chart, you must include:
o Fixed Costs line
o Variable Costs line
o Total Costs line
o Sales Revenue line
• Anything before the break-even (BE) point is loss
• Anything after the break-even (BE) point is profit
• ‘y’ axis measures money amounts (cost & revenue)
• ‘x’ axis shows the number of units produced or sold
• Total cost is variable cost line starting from fixed cost
• If the total cost increases, then the BE point increases
and total cost’s line becomes steeper
• If revenue increases, then revenue line becomes steeper
and so the break-even point decreases
• Benefits of break-even charts:
o Managers can read of the graph if the company
expects profit or loss, and can see how much
profit/loss the will have at any level of output
o They can attempt different scenarios and see the
impact it will have on the profit or loss of the
business. It lets managers try out different
possibilities to find out which one is the best. (i.e.
increasing the selling price, increasing production)
o It can be used to show the SAFETY MARGIN – the
amount by which sales exceed the break-even
point.
For example: if a business’ break-even point is at
400 units and they’re producing 600 units, their
safety margin is 600 – 400 = 200.
• Limitations of break-even charts:
o Break-even charts assume that all products made
will be sold. It does not show the possibility that
inventories may build up if they are not sold
o Fixed costs only stay the same if the scale of
production stays the same (doubling the output will
also increase the fixed cost because they must need
bigger factory, more machinery, labour, etc)
o Break even charts assume that costs and revenues
can be drawn with straight lines, which doesn’t
happen in real life.
• To calculate the break-even point:
Break Even = Fixed cost / contribution (per unit)
• Contribution – the selling price of a product (unit cost)
subtracted by the variable cost (per unit):
Contribution = unit cost – variable cost (per unit)
Variable cost (per unit) = Variable cost / units produced
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4.3 Achieving Quality Production
o
o
Fewer customer complaints
Reduced costs if products don’t have to be scrapped
or reworked or service repeated
• Drawbacks of Quality Assurance:
o Expensive to train employees to check products
o Relies on employees following instructions of the
standards set by company
• Total Quality Management (TQM) – the continuous
improvement of products and processes by focusing on
quality at each stage of production
• Total quality management is used by many companies
• It tries to “get it right the first time” and have no defects
• It focuses on ensuring 100% that the customer is always
satisfied. Customer is not just the final user, it also
includes other people and departments within the
business
• This means that quality needs to be maintained
throughout the business and no faults should occur.
• Advantages of total quality management:
o Quality is built into each part of the production. It
becomes a habit for the employees
o Eliminates virtually all faults/errors before the
customers receives.
o No customer complaints so brand image is
improved
o Waste is removed and efficiency increases which
means less money is wasted (higher profits)
• Drawbacks of total quality management
o very expensive to train employees to check the
product or service at every stage of production
o relies on employees following the ideology of TQM
• Quality – to produce a good or a service which meets
customer expectations
• Quality is important for businesses because:
o It establishes brand image
o It builds brand loyalty
o It maintains a good reputation
o It will help to increase sales
o Attracts more and new customers
• If quality is not maintained, businesses will:
o Lose customers to other brands / competitors
o Have to replace faulty products or repeat poor
service which raises costs for business
o Have a bad reputation because people who had bad
experiences will tell other people, etc. Leads to lower
sales & revenue
• Quality Control – Checking for quality at the end of the
production process, whether it is a product or a service.
• Quality control is a traditional way to make sure that
products leave the factories with no defects
• The jobs of people in quality control departments are to
take samples at regular intervals to check for errors.
• If errors are found, the whole batch of production might
have to be redone.
• Their job is also to prevent any production errors before
they happen during production, which will lead to money
loss
• Sometimes, businesses bring a mystery customer to test
out the service to check if the quality is as expected
• Advantages of Quality Control:
o Eliminates faults/errors before customer receives
product or service
4.4 Location Decisions
o Less training is required for the workers
• Factors that influence the choice of location of a
• Drawbacks of Quality Control:
business:
o Expensive, as employees need to be paid to check
o Labour (cost & skills) – how many employees and if
the product or service
they rely on special labour skills
o Identifies the fault but not how and why it occurred
o Cost of land/premises –big manufacturing
so it is difficult to remove the problem
companies need lots of cheap land to build
o Increased costs if products have to be scrapped or
o Transport links (supplies & distribution) – being
reworked or service repeated
close to transport links (i.e. rail road) means that
• Quality Assurance –checking for the quality standards
products can be easily and quickly transported
throughout the production process
which reduces time wasted. and if business imports
• Advantages of Quality Assurance:
lots of components it will be cheaper if they easy
o Eliminates faults/errors before customer receives
transported
product or service
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o
Sales technique – if a company does online or
phone sales, then the company doesn’t need to be
in the centre of the city. If it relies on personal visits
buy customers, like retail, it should.
o What the business does – manufacturing
businesses are usually in the outskirts of a city
where land is cheaper because they don’t rely on
customer visits. A retail company would be near
customers
o Number / location of competitors – having
competitors nearby is not always a bad thing. If
there are many clothes shops right next to each
other, it encourages people to visit area because
there is lots of choice, increases business.
• Some businesses may decide to locate their operations
in another country, to expand operations. the business
then becomes a TNC – Trans National Company.
• Factors influencing decision of which country to locate
operations in:
o New market overseas - when a business sees an
increase in sales overseas, it may decide to
move/relocate there, instead of transporting
products there
o Cheaper Source of material – if the raw material
runs out, the business must either bring in
alternative supplies from somewhere else or
relocate to new country with these raw materials, it
also might be cheaper than transporting it
o Difficulties with the labour force and wage costs –
if business is located in country where wages keep
rising, business may decide it is more profitable to
relocate to country where wages are lower
o Rents/taxes considerations – if other costs such as
rent or taxes increase, this might cause business to
relocate to countries where it is lower
5. FINANCIAL INFORMATION AND DECISIONS
5.1. Needs of Capital
Finance = Capital = Money
• Main reasons why businesses need finance:
o To start up a business: the money needed to buy the
essential assets to start trading is the start-up capital
o To expand the business
o To increase working capital
• Working capital - money needed to pay day-to-day costs
• There are 2 types of finance needs:
o Short-Term Finance Needs:
Finance needs to pay things that last less than a year,
(working capital) - includes wages, rent
o Long-term Finance Needs:
long term investments (that last more than 1 year).
Money to buy Fixed Assets (i.e. buildings)
5.1.2 Sources of capital
• The main sources of capital include:
o Internal Sources – Obtained by business itself
o External Sources – Obtained from outside business
Examples:
Internal sources
External sources
Retained profit
Issue of shares (if it’s LTD/PLC)
Sales of assets
Bank loans/Micro-finance
Grants
• Micro-Finance - providing smaller loans to poorer people
to start up their own business.
• Micro finance is very important in developing countries
• There are also short-Term and long-term sources (don’t
get confused with short/long term finance needs)
o Short Term Sources – money that must be paid back in
less than a year
o Long Term Sources – money that can be paid back in
longer than one year
Short-Term Sources
Long-Term Sources
Overdrafts – when the
Bank loans
bank allows a business to Issuing shares
spend more money than
Owner’s savings
they have in their account Hire Purchase – When a
(i.e. to pay employees)
business buys a fixed
Trade Credit – delay paying
asset in monthly
suppliers to be in better
payments (which
cash position
include interest)
• The main factors considered in making financial choice:
o Size of business & Legal Form (type of business):
Public limited companies have larger choice of sources
of finance because they pay less interest (less risk)
o Amount of capital required: if you need just a little
money you won’t issue new shares
o Purpose of capital & time period: The general rule is
that the finance source should match the finance need:
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CIE IGCSE BUSINESS STUDIES//0450
5.3 Income Statements
▪
If use of capital is long-term, source
should be long-term (same with
short term)
o Existing Loans: if a business already took out lots of
loans, banks will think it is too risky to finance
5.2 Cash-Flow Forecasting & Working Capital
• Cash is a Liquid Asset – it can be immediately available
to spend on goods & services
• Cash Flow – the cash inflows (money received by
business) & outflows (money paid) over a period of time
• Cash-Flow Forecast – an estimate of future cash inflows
and outflows.
• A cash-flow forecast shows the expected cash balance at
the end of each month:
• Cash flow forecasts are just little charts with values
comparing 2 different time periods (months/years etc.)
• Net Cash Flow – The difference between the cash inflow
and outflow (inflow – outflow)
• Cash flow forecasts are useful because:
o They show how much cash is available to pay liabilities
of to buy assets
o They show how much money a business might need to
borrow from a bank
o They show whether the business is holding too much
cash which could be reinvested back into business
• To complete a cash-flow forecast, just rearrange and use
the equation (net flow = inflow – outflow)
• Short-term cash-flow problems can be solved by
gathering short-term sources of finance
Working Capital
• Working capital is the money needed to pay day-to-day
costs
Working Capital = Current Assets – Current Liabilities
• A business cannot run without enough working capital
• You can measure the success of a business by seeing
how much working capital it has
• Working capital should be handled properly because it
shows investors & banks how efficient a business is and
its financial strength
• For most business, profit is the main objective
• Profit is the money left over after total costs have been
subtracted from the sales revenue.
The simple equation for profit:
Profit = Sales revenue – total costs
• Profit can be made by:
o Increasing the sales revenue, so that it is higher than
the production costs
o Reducing the production costs
• Profit is very important, especially for the private sector
companies (not owned by government)
o Profit is a reward for risk taking: investors &
entrepreneurs take lots of risks when investing money
o Profit is a reward for enterprise: entrepreneurs and
workers put lots of effort to make business succeed
o Profit can be re-invested back into business: the
retained profits can be put onto business to expand
o Profit indicates that the market might be successful: a
market where most businesses are making profit would
be a good market for an entrepreneur to start their
own
Profit ≠ Cash
• Profit can be in the form of cash, but it can also be in the
form of credit (customers will pay later)
• If a company makes $40,000 in sales, but only $20,000 is
in cash and the other $20k is in credit. The business only
has $20,000 in cash to pay costs.
• Credits can vary from a week to a year, it is ‘promised’
cash but not physical, and can’t pay for costs.
• So, in this case, if the business makes $40,000, and the
costs are $15,000 it will make $25,000 in gross profit
(theoretical profit), but only $5,000 in net profit
• Income Statement – A business account that records all
the incomes of a business and all the cost payed over a
year – to see if it is making profit.
• It will be used by managers, banks and other investors to
see if a business is making profit:
o to compare with previous years - if it is greater than
the year before
o To see if it is higher than competitors
• The main features of an income statement include:
o Revenue
o Costs
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CIE IGCSE BUSINESS STUDIES//0450
o Gross Profit – the profit made after costs of goods
sold are taken away from sales revenue
o Net Profit (AKA ‘Profit’) – the profit made after
taking away all expenses and overhead costs (other
expenses)
o Retained Profit – the net profit after taking away
taxes and payments to owners – which is reinvested
back into the business
Profit Type
Equation
Gross Profit Sales Revenue - Costs of goods sold
Gross Profit – Overhead Costs
Net Profit
(wages, electricity, rent, marketing)
Retained
Net Profit – (tax + dividends)
Profit
• Income statements are very important in decision
making in a business
• If a business is thinking to relocate a factory, they will
make a forecast income statement in both locations and
compare
5.4 Balance Sheets:
• Balance Sheet – a document that shows the value of the
business’ assets and liabilities in a point in time
• A balance sheet
• Assets – Items of value owned by a business
• Liabilities – Debts owed by business
• There are 2 types of assets:
o Current Assets – (Short-term Assets) Items owned by
business for less than 1 year
i.e. Raw material, cash
o Non-Current Assets – (Long-term Assets) Items owned
by business for more than 1 year
i.e. Buildings, land, company cars
• There are also 2 types of liabilities:
o Current Liabilities – (Short Term Liabilities) Debts
owed by business for less than 1 year
i.e. Bank overdrafts, wages
o Non-Current Liabilities – (Long Term Liabilities) Debts
owed by business for more than 1 year
i.e. Long-term bank loans, creditors (money that
business owes to suppliers)
• the Total Equity (AKA Shareholders’ funds) is how much
a business is worth. (only for Limited companies)
Shareholders’ Funds = Total Assets – Total Liabilities
• The shareholders’ funds is the total amount of money
invested in a business by the shareholders/owners
• If the total equity of a business has increased/fallen, the
shareholder’s stake of the company will be worth
more/less, respectively
From a balance sheet, you can calculate the
Working Capital = Current Assets - Current Liabilities
You can also calculate the Capital Employed – the longterm capital invested in a business
Capital Employed = Non-Current Assets + Total Equity
Total Equity = Shareholders’ funds
5.5 Analysis of Accounts
• Using all of the documents and information from cash
flow forecasts, balance sheets and income statements
you can rate the performance of a business
• Analysis of accounts is interpreting these
accounts/documents to see how a business is doing
• To rate a company’s performance, you can use 5 ratios
• There are 2 types of ratios:
o Profitability Ratios – how profitable a business is
o Liquidity Ratios – how able a business is to pay its
short-term debts (current liabilities)
• Profitability Ratios:
o Gross Profit Margin (%) – how good a company is at
converting sales into gross profit. A percentage
GPM (%) = 100 × Gross Profit / Sales Revenue
o Net Profit Margin (%) – how good a company is at
converting sales into net profit. A percentage
NPM (%) = 100 × Net Profit / Sales Revenue
o Return on capital employed – how profitable a
company is compared to the amount of money used
RoCE (%) = 100 × Net Profit / Capital Employed
• One profitability ratio isn’t useful by itself. You need to
use all the profitability ratios and compare it with
previous years of the business.
• Liquidity Ratios:
o Current Ratio – how good a company is to pay off its
current liabilities with its current assets
Current Ratio = Current Assets / Current Liabilities
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CIE IGCSE BUSINESS STUDIES//0450
o Acid Test Ratio – measures the ability of a company to
pay off its liabilities without depending on the sales of
inventory
Acid Test Ratio = Current Assets – Inventories (Stock)
Current Liabilities
• The acid test ratio is used to measure if a business is
likely to survive in the future
• The good and bad values of these ratios:
Gross Profit Margin No exact value, you must
compare with:
(%)
• Competitor businesses
Net Profit Margin
• Previous years
(%)
• The targets set by the
ROCE (%)
business
Current Ratio
Should be above 1.5 to be safe
Should be above 1, unless you
are dealing with cash sales in
Acid Test Ratio
which it can be above 0.75 (cash
is liquid - pays of liabilities easily)
• Liquidity – Ability for a business to pay off it short term
debts
• If a business’ assets can’t be easily converted to cash,
then they are Illiquid
• Current Assets are liquid.
• Having lots of stock may mean that the company might
be illiquid because inventories are hard to convert to
cash easily
• Liquidity is very important for a business:
o If they can’t convert their assets into cash, they won’t
be able to pay their suppliers (current liabilities)
o Not paying suppliers will force them to stop trading to
pay back their debts
5.5.3 Why and how accounts are used:
• Limited companies must publish their accounts for the
public to see. IT is used for ratio analysis.
• All types of stakeholders will be interest in seeing these
accounts to see how well the business is doing. i.e.:
o Managers: to keep an eye on the performance of the
business. Compare ratios with competitors & previous
years to make decisions.
o Shareholders & potential investors: They will see how
profitable a business is using the ratios to see if it is
worth investing in it. See how much business is worth
o Banks: see if business is performing well to calculate
the risk on whether to give out a loan or not.
o Employees: to see how safe the business (and their
jobs) are.
6. EXTERNAL INFLUENCES ON BUSINESS ACTIVITY
6.1 Government Economic Policies &
Objectives
• Inflation – The increase of average prices of goods &
services
• Governments want 3 main economic objectives:
o Low Inflation: Low prices of goods & services, so
people will buy more, more money in economy
o Low Unemployment: High % of people working so that
they don’t rely on government funds
o Economic Growth: growth of the GDP (Gross Domestic
Product) of a country – more goods and services being
produced and sold
o Balance of payment (of Imports & Exports): the
difference between the imports and the exports of a
country balance out (BoP = Exports – Imports)
• Exports are goods/services sold from one country to
another – and they bring money into a country
• Imports are the opposite
• An economy does not grow steadily, there are bumps
where the economy does not grow at all
• Recession – A period of falling GDP
• Economies go through the ‘Business Cycle’:
1. Growth: GDP is rising,
unemployment
falling, businesses
succeeding & higher
living standards
2. Boom: Higher living
standards so people
start spending more
money, so prices increase – business costs will also rise
3. Recession: people become uncertain about their jobs
so they don’t spend money. Many workers lose their
jobs because of lack of demand & profit in a business
4. Slump – A long-term, serious recession: Unemployment
will be very high, GDP has decreased a lot and many
businesses will not survive and go bankrupt
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CIE IGCSE BUSINESS STUDIES//0450
6.1.1 Government Economic Policies
Interest Rates
• There are 3 main ways governments can influence the
economy (AKA economic policies):
o Government expenditure
Fiscal Policy
o Changing tax rates
o Interest Rates
• Government Expenditure is how the government spends
the money made from taxes. It is usually spent on
education, defense, healthcare, public transport, etc.…
• Companies that are involved in these markets/sectors
above will benefit. i.e. a bus manufacturing company will
benefit if government spends more on public transport
• Spending more on these markets will boost economy in
a country (more jobs created, more demand)
• There are 2 types of taxes:
o Direct Taxes – taxes paid directly from incomes (of
individuals as wages or as business as revenue)
o Indirect Taxes – VAT, taxes added to prices of goods
• Out of these 2 types, there are 4 common taxes that
affect business activity:
• The interest rate is the amount charged for borrowing
money from a bank
• In most countries, the interest rates are fixed by the
government
• the % of the interest rate is called the monetary policy
• The effects to business activity due to having higher
interest rates include:
o Less profit for companies that already took out a loan less/slower expansion of a business.
o Entrepreneurs thinking of starting business might not
be able to afford to take out a loan
o If consumer loans (i.e. mortgages) increase, people will
have less disposable income – less demand for goods
o Higher exchange rates of currency
Tax
Income
tax
(direct
tax)
Profits
Tax
(direct
tax)
Indirect
Tax
(VAT)
Import
Tariffs &
Quotas
(indirect)
What it is
Tax on people’s incomes –
You can either have a set
tax (i.e. 20% of income) or
Progressive income tax,
where richer people pay
higher taxes.
Tax on profits made by
businesses (a set
•
percentage)
•
Tax added to prices of
goods & services (varies
within types of products)
Tax on imported goods
•
from other countries.
Import Quota is a physical
limit to the amount of
•
products that can be
imported.
How it affects business
activity
People have less disposable
income (money after tax).
They would have less
money to spend on goods
or services. Businesses
have less revenue.
If tax rates increase:
Harder for a business to
expand (less profit) less
money to reinvest back
into business.
Fewer people will start
their own business
Prices of goods will
increase so less people will
buy them – Less demand
for a business
Local businesses will have
more demand because
there less imported goods
Importing raw materials
from abroad will be much
more expensive – products
will be more expensive –
sell less
• Businesses might respond to all of these policies by:
Policy
Business Response
Higher
• Lowering production costs to be able to
income tax
sell goods for lower prices
Higher
• Focusing on the domestic market
tariffs (on • Buying materials from local companies
imports)
rather than from companies abroad
Higher
• Reduce investment for business growth
interest
• Lower prices of goods for consumers
rates
• Sell assets for cash to reduce loans
6.2 Environmental & Ethical Issues
• Business activity can impact the environment in many
different ways, including:
o Air pollution made by factories & transportation
o Water & land pollution from improper waste disposal
o Increase carbon emissions – global warming
• Most business decisions lead to benefits and costs.
There are private and external benefits and costs
• Private costs & benefits are costs that a business pays
for, and the benefits the business gains
• External Costs – costs paid by society, rather than the
business (as a result of business decision)
• External Benefits – gains to society, rather than the
business (as a result of business decision)
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CIE IGCSE BUSINESS STUDIES//0450
• The possible external costs and benefits of a business
decision might include:
External Costs
External Benefits
• Environment is harmed • Jobs are created,
from waste products
economy is boosted
• pollution may damage
• Other companies might
the health of people
move in, more services
• less energy
• better infrastructure
• traffic
• better quality of life
• these externalities change depending on the decision.
• Sustainable development – development that does not
compromise the living standards of future generations
• Businesses can contribute to sustainable development
by doing 4 main things:
1. Using renewable energy (wind, solar)
2. Recycling & reusing their waste
3. Using less natural resources (lean production)
4. Developing environmentally friendly products &
packaging (i.e. biodegradable packaging)
• People & consumers pressure companies to think more
environmentally. There are many reasons and ways
businesses give the environment a higher priority:
• Pressure groups - a group of people who want to change
policies/decisions of businesses or the government.
• Pressure groups acting on unethical decisions made by a
business will lead to a consumer boycott - consumers
not buying their products
• Environmentally friendly businesses can use the fact that
they are environmental as a marketing advantage
Type of
pressure
What it is
How and why it
responds
• Governments sell ‘permits’ to companies that allow it to
pollute the environment up to a certain level
• Firms that pollute less than the government allows, can
sell their permit to companies that pollute more
• This motivates businesses to pollute less, to earn money
• Ethics – “doing the right thing” - the moral principles
• Most businesses have to face many ethical decisions,
they have to decide whether to act ethically or have
higher profits
• Ethical decisions include:
o Employing child workers, even though it might not be
illegal in some countries
o Buying supplies that lead to damage of the
environment
o Paying managers large bonuses while having their
workers in minimum wage & poor conditions
o Offering bribes to people to gain information
• Different companies have different ethical standards
because people have different moral codes
• Businesses may respond to ethical issues by following
their moral code and “doing the right thing”
• These decisions have benefits and disadvantages:
Benefits
Disadvantages
• Consumers appreciate
• Higher costs of
the efforts made by the
production
company and so they
• Higher prices – might
buy more from them
lead to less demand
• Creates good publicity
• In some places families
• Less risk of lawsuits
depend on their children
to earn money
• Easier to find workers
They lead to consumer
boycotts - consumers not
buying their products
6.3 Business and the International Economy
• Lots of public
support
• Globalization –the world becoming more interconnected
• Very bad brand
leading to increasing worldwide trade & people moving
image &
• The reasons for globalization include:
reputation
o More Free-Trade Agreements – imports/exports
• Loss in sales
Laws passed
by
Government
Government making
certain activities illegal (i.e.
dumping waste)
• It is more
expensive to
manufacture
Fines
If a business produces more
pollution than the
government allows, they
pay heavy fines.
• Costs of
business
increase
Pressure
group
a group of people who
want to change policies /
decisions of businesses
between countries that pay no tariffs
o Easier, cheaper and faster transportation between
countries
o E-commerce allows products to be bought from all
over the world
o Industrializing countries (i.e. India & China) can
produce products at very low prices
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CIE IGCSE BUSINESS STUDIES//0450
• The opportunities and threats of globalization to a
business include:
•
•
•
•
Opportunities
Businesses can sell abroad,
increasing sales
Opening factories or offices
abroad – can be cheaper to
produce, but it is expensive to
set up
Importing materials from
abroad – can be cheaper but
transport costs can be too
high
Importing goods from abroad
and selling it in home country
Threats
• Increasing foreign competitors
importing their products,
leading to less sales (& profit)
• Workers in home country
might leave for higher wages in
other countries
• More foreign companies set
up operations in the home
country of the business, more
competition
• Sometimes governments introduce import tariffs and
quotas to protect local businesses – this is called
Protectionism
• They believe that by reducing the number of foreign
competitors and goods (that would have much lower
prices), there will be less unemployment and higher
incomes
• However, by doing this, it is harder for local businesses
to import materials and export their goods abroad
6.3.2 Multinational Companies (MNCs)
• Multinational Company = Transnational Company
• A multinational company is a company that has factories
or service operations in more than one country
• It is not just selling products abroad, it is having
operations abroad
• The benefits of a business becoming international:
Benefits to the business
Producing goods at lower costs
Closer to resources (i.e. oil)
Closer to market
Avoid expensive taxes of import of
goods (i.e. Korean cars (KIA) being
produced in EU to benefit from free
trade)
• Spread risks (if there are low sales in
one country and high sales in
another)
•
•
•
•
Benefits to the country
• Jobs are created
• Investments in
development of
infrastructure in
country
• More exports
• Tax – more money to
government
• increased product
choice for consumers
• However, there are potential drawbacks to the country:
o Less sales for local businesses, might go bankrupt
o ‘Repatriation of profits’ – profits are sent back to
home country and doesn’t benefit country located
o Business has lots of influence on government – they
can threaten to leave the country
o They can use up scarce resources in the country
6.3.3 Exchange Rates
• Exchange Rate – the price of one currency in terms of
another currency
• For example, 1 Euro is equivalent to 1.2 Dollars
• Currency Appreciation – when the value of a currency
increases (i.e. 1€ = 1.2$ → 1€ = 1.7$)
• Currency Depreciation – when the value of a currency
increases (i.e. 1€ = 1.2$ → 1€ = 1.1$) – it can buy less of
another currency
• The exchange rate of a currency is influenced by 2
things:
o Demand for the currency: if many people want to buy
the currency the price will increase because there is a
‘limited’ number of currency (appreciate)
o Supply of currency: if the central bank prints more
money, the supply increases but the demand is still the
same so the value is lower (depreciation)
• Exchange rates can affect businesses by:
If it Appreciates:
• Import prices fall: since
your currency can buy
more of the other
currency
• Export prices rise: your
currency is worth more so
it is more expensive for
other currencies to buy it
If it Depreciates:
• Import prices rise: your
currency is worth less so
you need more to buy other
currencies
• Export prices fall: it is worth
less so other currencies can
buy your currency for les of
theirs
• This means that if the currency Appreciates:
o The product’s price in other countries will increase
o Business will make more profit
o Business can lower the price and still make the same
amount of money as before – it is more competitive
• If the currency depreciates:
o The products price in other countries will decrease
o less profit will be made
o Business needs to raise the price to make the same
amount of money as before – less competitive
Page 30 of 30
TABLE OF CONTENTS
3
CHAPTER 1
3
CHAPTER 2
3
CHAPTER 3
4
CHAPTER 4
4
CHAPTER 5
5
CHAPTER 6
5
CHAPTER 7
6
CHAPTER 8
6
CHAPTER 9
6
CHAPTER 10
Length & Time
Motion
Mass & Weight
Density
Forces
Momentum
Energy, Work & Power
Pressure
Simple Kinetic Molecular Model of Matter
Thermal Properties
7
CHAPTER 11
7
CHAPTER 12
10
CHAPTER 13
10
CHAPTER 14
12
CHAPTER 15
13
CHAPTER 16
13
CHAPTER 17
15
CHAPTER 18
17
CHAPTER 19
17
CHAPTER 20
Transfer of Thermal Energy
General Wave Properties
Light
Sound
Simple Phenomena of Magnetism
Electrical Quantities
Electrical Circuits
Dangers of Electricity
Electromagnetic Effects
Radioactivity
CIE IGCSE PHYSICS//0625
1. LENGTH AND TIME
2. MOTION
1.1 Length
2.1 Speed
 A rule (ruler) is used to measure length for distances
between 1mm and 1meter
 SI unit for length is the meter (m)
 To find out volume of regular object, use mathematical
formula
 To find out volume of irregular object, put object into
measuring cylinder with water. When object added, it
displaces water, making water level rise. Measure this
rise. This is the volume.
 Speed is the distance an object moves in a time frame. It
is measured in meters/second (m/s) or kilometers/hour
(km/h).
 
 =
 
 Speed is a scalar quantity
2.2 Speed/Time Graphs
1.2 Micrometer Screw Gauge
 Used to measure very small distances
 Determination of the diameter 'd' of a wire
 Area under the line equals to the distance travelled
  =
2 −1
2 −1
= =Acceleration (m/s)2
2.3 Distance/Time Graphs
 Place the wire between the anvil and spindle end as
indicated in the diagram.
 Rotate the thimble until the wire is firmly held between
the anvil and the spindle.
 The ratchet is provided to avoid excessive pressure on
the wire. It prevents the spindle from further movement
- squashing the wire
 To take a reading:
o First look at the main scale. This
has a linear scale reading on it.
The long lines are every
millimetre the shorter ones
denote half a millimetre in
between.
o On the diagram this reading is
2.5 mm
o Now look at the rotating scale. That denotes 46
divisions - each division is 0.01mm so we have
0.46mm from this scale.
o The diameter of the wire is the sum of these readings:
o 2.5 + 0.46 = 2.96 mm
1.3 Time
 −
  =  −= Speed (m/s)


2.4 Distance
 Calculating distance travelled:
o With constant speed:  × 

o With constant acceleration:  +
× 
2
2.5 Acceleration
  −  
 
 Acceleration is the rate of change in velocity per unit of
time, measured in meters per second, or m/s2
 Acceleration is a vector quantity
 Positive acceleration means the velocity of a body is
increasing
 Deceleration or negative acceleration means the velocity
of a body is decreasing
 If acceleration is not constant, the speed/time graph will
be curved.
 The downwards acceleration of an object is caused by
gravity. This happens most when an object is in free.
 =
 Interval of time is measured using clocks
 SI unit for time is the second(s)
 To find the amount of time it takes a pendulum to make
a spin, time ~25 circles and then divide by the same
number as the number of circles.
PAGE 3 OF 20
CIE IGCSE PHYSICS//0625
 Objects are slowed down by air resistance. Once air
resistance is equal to the force of gravity, the object has
reached terminal velocity. This means that it will stay at
a constant velocity. acceleration of free fall for a body
near to the Earth is constant (G=10m/s)
3. MASS AND WEIGHT
 Mass: amount of matter an object contains, and is a
property that ‘resists’ change in motion
 Weight is the force of gravity acting on an object,
measured in Newtons, and given by the formula:
 =  × 
 Weights (and hence masses) may be compared using a
balance
5. FORCES
5.1 Effects of Forces
 A force may produce a change in size and shape of a
body, give an acceleration or deceleration or a change in
direction depending on the direction of the force.
 If there is no resultant force acting on a body, it either
remains at rest or continues at constant speed in a
straight line
5.2 Friction
 Friction: the force between two surfaces which impedes
motion and results in heating
 Air resistance is a form of friction
5.3 Hooke’s Law
4. DENSITY

 =

 Density of a liquid: place measuring cylinder on a
balance, fill measuring cylinder with the liquid. The
change in mass is mass of liquid and volume is shown on
the scale, then use formula.
 Density of solid:
o Finding the volume: To find out volume of a regular
object, use mathematical formula. To find out volume
of an irregular object, put object into a measuring
cylinder with water and the rise of water is the volume
of the object
o Finding the mass: weigh object on a scale and use
formula
4.1 Flotation
 The density of water is 1g/cm3, if an object has a greater
density than that, then it will sink in water, and if the
object’s density is less than that, then it will float in
water.
 Example: an orange with its peel has a
density of 0.84g/cm3, we can predict that
it will float because it is less than 1 g/cm3.
We can also say, that an orange without its
peel, which has a density of 1.16g/cm3, will sink because
it is greater than 1g/cm3.
 Springs extend in
proportion to load, as
long as they are under
their proportional limit.
point at
 Limit of proportionality:
which load and
extension are no longer
proportional
 Elastic limit: point at which the spring will not return to
its original shape after being stretched
() =   × 
 = 
5.4 Forces
 Forces measured in Newtons
 =  × 
 1 Newton is the amount of force needed to give 1kg an
acceleration of 1m/s2
5.5 Circular Motion
 An object at steady speed in circular orbit is always
accelerating as its direction is changing, but it gets no
closer to the center
 Centripetal force is the force acting towards the center
of a circle. It is a force that is needed, not caused, by
circular motion,
 For example, when you swing a ball on a string round in
a circle, the tension of the string is the centripetal force.
If the string is cut then the ball will travel in a straight
line at a tangent to the circle at the point where the
string was cut.
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CIE IGCSE PHYSICS//0625
 Centrifugal force is the force acting away from the
center of a circle. This is what makes a slingshot go
outwards as you spin it. The centrifugal force is the
reaction to the centripetal force. It has the same
magnitude but opposite direction to centripetal force.

=

5.10 Scalars and Vectors
 A scalar is a quantity that only has a magnitude (so it can
only be positive) for example speed.
 A vector quantity has a direction as well as a magnitude,
for example velocity, which can be negative.
5.6 Newton’s Laws
 First law of motion: If no external for is acting on it, an
object will, if stationary, remain stationary, and if
moving, keep moving at a steady speed in the same
straight line
 Second law of motion:  = 
 Third law of motion: if object A exerts a force on object
B, then object B will exert an equal but opposite force on
object A
5.7 Moment
() = () ×   ()
 In equilibrium, clockwise moment = anticlockwise
moment.
 Increasing force or distance from the pivot increases the
moment of a force
 Levers are force magnifiers
o Turning a bolt is far easier with a wrench because
distance from pivot is massively increased, and so is
the turning effect
5.8 Centre of Mass
 Centre of mass: imaginary point in a
body where total mass of body
seems to be acting
 Working out the center of mass:
o Mark three points on the edge of
the card
o Make a hole using a pin on each
point
o Hang it on a cork board and make a line when it is
stable
o Do this for all three points
o Where all three lines intersect, this is the center of
mass
5.9 Stability
6. MOMENTUM
 Linear momentum: product of mass and velocity
 = 
 Principle of conservation of linear momentum: when
bodies in a system interact, total momentum remains
constant provided no external force acts on the system.
  +   =   +  
 Impulse: product of force and time for which it acts
 =  – 
7. ENERGY, WORK, AND POWER
7.1 Energy
 Energy: amount of work and its measured in Joules (J)
 An object may have energy due to its motion or its
position
 Conservation of energy: energy cannot be created or
destroyed, when work is done, energy is changed from
one form to another
 Energy can be stored
ENERGY TYPE
WHAT IT IS
EXAMPLE
KINETIC
Due to motion
Car moving
GRAVITATIONAL From potential to fall Book on shelf
Bonds in starch
CHEMICAL
In chemical bonds
(food)
Stretched elastic
STRAIN
Compress/stretch
band
Atoms
Released in
NUCLEAR
rearranged/split
nuclear plant
In a glass of
INTERNAL
Motion of molecules
water
ELECTRICAL
Carried by electrons Battery to bulb
LIGHT
Carried in light waves From sun
Carried in sound
SOUND
From speaker
waves
 An object will be in stable equilibrium when it returns to
its original position given a small displacement
 For an object to start rotating it needs to have an
unbalanced moment acting on it
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CIE IGCSE PHYSICS//0625
  = 1⁄2 ×  ×  2
. . = ⁄ 
  
=  ×  × ℎ
. . . = 
 Example of conversion of energy: A book on a shelf has
g.p.e , if it falls of the shelf it will have k.e
7.2 Energy Resources
 Renewable sources are not exhaustible
 Non-renewable sources of energy are exhaustible
TYPE
ADVANTAGES
DISADVANTAGES
Fuel: burnt to
 Harmful wastes:
 Cheap
make thermal
o Greenhouse/
energy, makes
 Plentiful
pollutant gas
steam, turns
 Low-tech
o Radiation
turbine
Wave energy:
generators driven
 No greenhouse
by up and down
 Difficult to build
gases produced
motion of waves
at sea.
Tidal energy: dam
built where river
meets sea, lake
fills when tides
 Expensive
 No greenhouse
comes in &
 Can’t be built
gases produced
empties when
everywhere
tide goes out;
water flow runs
generator
Hydroelectric:
river & rain fill up  Low impact on
lake behind dam, environment
 Few areas of the
water released,  Energy produced world suitable
at constant rate
turns turbine 
generator
Geothermal:
 Deep drilling
water pumped
 No CO2
difficult and
down to hot rocks produced
expensive
rising as steam
Nuclear fission:
 Produces a lot of
uranium atoms
 Produces
energy with very
split by shooting
radioactive waste
little resources
neutrons at them
Solar cells: made
of materials that
deliver electrical
current when it
 Variable amount
 No CO2
absorbs light
of sunshine in
produced
some countries
Solar panels:
absorbs energy
and use it to heat
water
 The sun is the source of energy for all our energy
resources except geothermal, nuclear and tidal
 In the sun, energy is created through a process called
nuclear fusion: hydrogen nuclei are pushed together to
form helium.
 Efficiency: how much useful work is done with energy
supplied
  
× %
 
  
 =
× %
 
 =
7.3 Work
 Work is done whenever a force makes something move.
 The unit for work is the Joule (J).
 1 joule of work = force of 1 Newton moves an object by 1
meter
  () =  () ×  ()
 = 
7.4 Power
 Power is the rate of work
 The unit for power is Watts (W)
 1W = 1J/s
 () =
  ()
  ()
8. PRESSURE
8.1 Pressure in Solids
 () =
=
 Unit: Pascals (Pa) = N/m2
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 ()
 ( )
CIE IGCSE PHYSICS//0625
8.2 Pressure in Liquids
() = (/ ) × (/ ) × ()
 = 
 At a depth of 10m in water, the pressure is always
100,000 Pa (1bar) and is constant for each further 10m.
8.3 Atmospheric Pressure
 1 atm = 101.325 X 103 Pa = 101 KPa
MANOMETER
BAROMETER
 Atoms vibrate
 No fixed pattern,  Particles far
but can’t change liquids take
apart, and move
position ∴ fixed
shape of their
quickly
volume and
container
 Collide with each
shape
 Particles slide
other and
past each other. bounce in all
directions
9.2 Pressure in Gases
 The pressure gases exert on a container is due to the
particles colliding on the container walls.
 If the volume is constant, then increasing the
temperature will increase the pressure.
9.3 Brownian Motion
 A manometer measures
the pressure difference.
 The height difference
shows the excess
pressure in addition to
the atmospheric
pressure.
 Tube with vacuum at the
top and mercury filling
the rest.
 Pressure of the air
pushes down on
reservoir, forcing
mercury up the tube.
 Measure height of
mercury
 ~760 mm of mercury is 1
atm.
9. SIMPLE KINETIC MOLECULAR MODEL OF
MATTER
9.1 States of Matter
SOLID
LIQUID
GAS
 Fixed shape and  Fixed volume but  No fixed shape
volume
changes shape
or volume, gases
 Strong forces of
depending on its fill up containers
attraction
container
 Almost no
between
 Weaker
intermolecular
particles
attractive forces forces
 Fixed pattern
than solids
(lattice)
 Gas molecules move at a random motion
 This is because of repeated collisions
with other gas molecules
 Small molecules move much faster and have higher
energy than larger molecules
 The small particles can help move the larger particles
 Brownian motion can be seen visually in smoke
9.4 Evaporation
 It is the escape of more energetic particles and occurs
constantly on surface of liquids.
 If more energetic particles escape, liquid contains few
high energy particles and more low energy particles so
average temperature decreases.
 Evaporation can be accelerated by:
o Increasing temperature: more particles have energy
to escape
o Increasing surface area: more molecules are close to
the surface
o Reduce humidity level in air: if the air is less humid,
fewer particles are condensing.
o Blow air across the surface: removes molecules
before they can return to liquid
9.5 Pressure Changes
  =  
10. THERMAL PROPERTIES & TEMPERATURE
10.1 Thermal Expansion of Solids, Liquids &
Gases
 Solids, liquids and gasses expand when they are heated
as atoms vibrate more and this causes them to become
further apart, taking up a greater volume.
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CIE IGCSE PHYSICS//0625
 Due to differences in molecular structure of the different
states of matter, expansion is greatest in gases, less so in
liquids and lowest in solids
 Applications and consequences of thermal expansion:
o Overhead cables have to be slack so that on cold
days, when they contract, they don’t snap or detach.
o Gaps have to be left in bridge to allow for expansion
o Bimetal thermostat: when temperature gets too high,
bimetal strip bends, to make contacts separate until
temperature falls enough, then metal strip will
become straight again and contacts touch, to maintain
a steady temperature
 For a fixed mass of gas at constant pressure, the volume
is directly proportional to the Kelvin temperature
10.2 Measurement of Temperature
 A physical property that varies with temperature may be
used for measurement of temperature
 Liquid-in-glass thermometer:
o As temperature rises or falls, the liquid (mercury or
alcohol) expands or contracts.
o Amount of expansion can be matched to temperature
on a scale.
 Thermistor thermometer:
o The probe contains a thermistor
o The thermistor is a material that becomes a better
electrical conductor when the temperature rises
(semi-conductor)
o So when temperature increases, a higher current
flows from a battery, causing a higher reading on the
meter
 Thermocouple thermometer:
o The probe contains 2 different metals joined metals
to form 2 junctions.
o The temperature difference causes a tiny voltage
which makes a current flow.
o A greater temp. difference gives a greater current.
o Thermocouple thermometers are used for high
temperatures which change rapidly and have a large
range (-200C° to 1100°C)
 Fixed points are definite temperatures at which
something happens and are used to calibrate a
thermometer. For example, melting and boiling point of
water
 Calibrating a thermometer:
o Place thermometer in melting ice, this is 0 °C.
o Place thermometer in boiling water, this is 100 °C.
 Sensitivity: change in length or volume per degree
 To increase sensitivity:
o Thinner capillary
o Less dense liquid
o Bigger bulb
 Range: change the upper and lower fixed points
 Linearity: change the distance between intervals
o Responsiveness: how long it takes for the
thermometer to react to a change in temperature
10.3 Melting
 This is when a solid turns into a liquid.
 Temperature increases thus kinetic energy in solid
increases and particles vibrate more rapidly but there is
no increase in temperature of the substance when
melting because thermal energy supplied is instead
being used to break bonds between particles of the solid
thus making it into a liquid.
 Boiling point is the temp. at which a substance boils
10.4 Boiling
 This is when a liquid turns into a gas
 Temperature increases thus kinetic energy in liquid
increases and particles vibrate more rapidly but there is
no increase in temperature of the substance when
boiling because thermal energy supplied is instead being
used to break bonds between particles of the liquid thus
making it into a gas.
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CIE IGCSE PHYSICS//0625
 Melting point is the temp. at which a substance melts
 The difference between boiling and evaporation is that:
o Boiling occurs at a fixed temperature and throughout
the liquid
o Evaporation occurs at any temperature and only on
the surface
10.5 Latent Heat
 The latent heat of fusion is the amount of energy needed
to melt 1Kg of a substance.
 The latent heat of vaporization is the amount of energy
needed to boil 1Kg of a substance
    / =
 / =


 

11.3 Convection
 Convection is the flow of heat through
a fluid from places of higher
temperature in places of lower
temperature by movement of the
fluid itself.
 As a fluid (liquid or gas) warms up, the
particles which are warmer become less dense and rise.
 They then cool and fall back to the heat source, creating
a cycle called convection current.
 As particles circulate they transfer energy to other
particles. If a cooling object is above a fluid it will create
a convection current
11.4 Radiation
10.6 Condensation and Solidification
 Condensation is when a gas turns back into a liquid.
 When a gas is cooled, the particles lose energy. They
move more and more slowly. When they bump into each
other, they do not have enough energy to bounce away
again so they stay close together, and a liquid forms.
 When a liquid cools, the particles slow down even more.
Eventually they stop moving except for vibrations and a
solid forms.
11. THERMAL PROCESSES
11.1 Conductors
 Good conductors are used whenever heat is required to
travel quickly through something
 Bad conductors (insulators) are used to reduce the
amount of heat lost to the surroundings
11.2 Conduction
 Conduction is the flow of heat
through matter from places of
higher temperature to places of
lower temperature without
movement of the matter as a whole
 In non-metals - when heat is supplied to something, its
atoms vibrate faster and pass on their vibrations to the
adjacent atoms.
 In metals – conduction happens in the previous way and
in a quicker way –electrons are free to move, they travel
randomly in the metal and collide with atoms and pass
on the vibrations.
 Radiation is the flow of heat from one place to another
by means of electromagnetic waves
 Thermal radiation is mainly infra-red waves, but very hot
objects also give out light waves. Infra-red radiation is
part of the electromagnetic spectrum.
MATT BLACK
WHITE
SILVER
EMITTER
Best
Worst
REFLECTOR Worst
Best
ABSORBER
Best
Worst
 An emitter sends out thermal
radiation.
 A reflector reflects thermal
radiation, therefore is a bad
absorber.
 An emitter will cool down quickly, an absorber will heat
up more quickly and a reflector will not heat up quickly
11.5 Application of Energy Transfer
 Solar panel: the sun’s thermal radiation is absorbed by a
matt black surface and warms up the pipes containing
water
 Refrigerator: the freezer compartment is located at the
top of the refrigerator. It cools down the air which then
sinks. Any warm air rises to the top and then is cooled.
This creates a convection current which maintains a cold
temperature.
 Metals used in cooking pans because they conduct heat
well
11.6 Consequences of Energy Transfer
 Metal spoon in a hot drink will warm up because it
conducts heat
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 Convection currents create sea breezes. During the day
the land is warmer and acts as heat source. During the
night the sea acts as the heat source.
 A black saucepan cools better than a white one, white
houses stay cooler than dark ones.
 When wave is slowed down, it is refracted towards
normal (i > r)
 When wave is sped up, it is refracted away from normal
(i < r)
 Deep water is denser than shallow water
12. GENERAL WAVE PROPERTIES
 Waves transfer energy without transferring matter
 Frequency: the number of waves passing any point per
second measured in hertz (Hz)

 =

 Period: time taken for one oscillation in seconds
 Wavefront: the peak of a transverse wave or the
compression of a longitudinal wave
 Speed: how fast the wave travels measured in m/s
 Wavelength: distance between a point on one wave to
the equivalent point on the next wave in meters
 Amplitude: maximum distance a wave moves from its
rest position when a wave passes
When water wave travels
from deep to shallow;
speed decreases,
wavelength decreases and
frequency remains
constant
When water waves
travel from shallow to
deep; speed increases
wavelength increases
and frequency remains
constant
12.2 Reflection
 Waves bounce away from
surface at same angle they
strike it
 Angle of incidence = angle of reflection
 Speed, wavelength and
frequency are unchanged by reflection
12.3 Diffraction
TRANSVERSE WAVES
LONGITUDINAL WAVES
 Travelling waves in
 Travelling waves in
which oscillation is
which oscillation is
parallel to direction of
perpendicular to
travel.
direction of travel

Has compressions and
 Has crests and troughs
rarefactions
 For example, light, water
 For example, sound
waves and vibrating
waves
string
 (/) = () × ℎ()
 = 
12.1 Refraction
 Speed and wave length is reduced but frequency stays
the same and the wave changes direction
 Waves slow down when they pass from a less to a more
dense material and vice versa
 Waves bend round the
sides of an obstacle, or
spread out as they pass
through a gap.
 Wider gaps produce
less diffraction.
 When the gap size is
equal to the wavelength, maximum diffraction occurs
13. LIGHT
13.1 Reflection of Light
 Plane (flat) mirrors produce a reflection.
 Rays from an object reflect off the mirror into
our eyes, but we see them behind the mirror.
 The image has these properties:
o Image is the same size as the object
o Image is the same distance from the mirror as object
o A line joining equivalent points of the image and
object meet the mirror at a right angle
o Image is virtual: no rays actually pass through the
image and the image cannot be formed on a screen
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 Laws of reflection:
Angle of incidence = angle of reflection
The incident ray, reflected ray and normal are always on
the same plane (side of mirror)
13.2 Refraction of Light
 Refraction is the bending when light travels from one
medium to another
13.3 Experimental Demonstration – Ray Box
 Using the ray box, pass a ray through a glass slab on a
white sheet of paper.
 Mark two points on the incident ray, refracted ray,
emergent ray and draw an outline of the glass slab with
a pencil on paper
 Then by connecting the dots you can produce a diagram
like the one below, a protractor is used to find the
angles.
 When a ray passes through a parallel sided transparent
material its passage will look like this:
 
 
  = − ⁄
  =
13.5 Optical Fibres
 Light put in at one end is totally internally reflected until
it comes out the other end.
 Used in communications: signals are coded and sent
along the fiber as pulses of laser light
 Used in medicine: an endoscope, an instrument used by
surgeons to look inside the body; contains a long bundle
of optic fibers.
13.6 Thin Converging Lens
 Principal focus: the point where rays parallel to the
principal axis converge with a converging lens.
 Focal length: distance from principle focus and the
optical center.
 Principal axis: line that goes through optical center, and
the 2 foci.
 Optical center: the center of the lens
 Real: image can be caught on a screen
 Virtual: image cannot be caught on a screen
Real Image
 When object is further away from the optical centre than
F’ is
 Note: the emergent ray is parallel to the incident ray
13.4 Critical Angle
 Angle at which refracted ray is parallel to the surface of
material.
 If angle of incidence is greater than the critical angle
there is no refracted ray, there is total internal
reflection.
 If angle of incidence is less than the critical angle the
incidence ray will split into a refracted ray and a weaker
reflected ray.
  =
A) A ray through centre of the lens passes straight through
the lens.
B) A ray parallel to the principal axis passes through the
focus on the other side of the lens
C) A ray through F’ will leave the lens parallel to the
principal axis
Virtual Image
 When the object is closer to the optical centre than F’ is
    
     
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CIE IGCSE PHYSICS//0625
 Magnifying glass: when a convex lens is used like this an object is closer to a convex (converging) lens than the
principal focus (like the diagram above), the rays never
converge. Instead, they appear to come from a position
behind the lens. The image is upright and magnified, it is
a virtual image.
13.7 Dispersion of Light
Refraction by a prism:
 When light is
refracted by a prism,
the incidence ray is
not parallel to the
emergent ray, since
the prism’s sides are
not parallel.
 If a beam of white light is passed through a prism it is
dispersed into a spectrum.
 White light is a mixture of colors, and the prism refracts
each color by a different amount – red is deviated least
& violet most
13.8 Light Spectrum
13.9 Electromagnetic Spectrum
All electromagnetic waves:
 Travel at the speed of light: 3 × 108m/s
 Don’t need a medium to travel through (travel through a
vacuum)
 Can transfer energy
 Are produced by particles oscillating or losing energy in
some way
 Are transverse waves
13.10 Uses
 Radio waves: radio and television communications
 Microwaves: satellite television and telephones
o Safety issue: cause internal heating of body tissues
 Infrared: electrical appliances (radiant heaters and
grills), remote controllers for televisions and intruder
alarms
 X-rays: medicine (x-ray photography and killing cancer
cells) and security
o Safety issue: is a mutagen, it cause cancer (mutations)
 Monochromatic: light of a single wavelength and color
(used in lasers)
14. SOUND
14.1 Production
 Sound waves come from a vibrating source e.g.
loudspeaker
 As the loudspeaker cone vibrates, it moves forwards and
backwards, which squashes & stretches the air in front.
 As a result, a series of compressions (squashes) and
rarefactions (stretches) travel out through the air, these
are sound waves
14.2 Properties
 Sound waves are longitudinal: they have compressions
and rarefactions and oscillate backwards and forwards.
 Humans can hear frequencies between 20 and 20
000Hz.
 Sound waves need a medium to travel through.
 Ultrasound Waves: high frequency sound waves,
medically used to look at structures and organs inside
the human body, i.e. to form an image of a fetus in a
pregnancy
 Compression: high pressure section of the wave
 Rarefaction: low pressure section of the wave
 The higher the frequency, the higher the pitch.
 The higher the amplitude, the louder the sound
14.3 Speed of Sound
MEDIUM
STATE
CONCRETE
Solid
PURE WATER
Liquid
AIR
Gas
  <   <  
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SPEED
5000 m/s
1400 m/s
330 m/s
CIE IGCSE PHYSICS//0625
14.4 Experiment: Finding Speed of Sound
 When sound reflects off of a wall, it will come back to
you; echo
 If you know the distance between you and the wall, and
measure how long it takes for the echo to sound, you
can figure out the speed of sound in air.
 Remember to take into account that sound has gone
there & back
15. SIMPLE PHENOMENA OF MAGNETISM
15.1 Properties of Magnets
 Has a magnetic field around it
 Has 2 opposite poles (North and South) which exert
forces on other magnets. Like poles repel and unlike
poles attract.
 Will attract magnetic materials by inducing (permanent
or temporary) magnetism in them.
 Will exert little or no force on a non-magnetic material
 The direction of an electric field at a point is the
direction of the force on a positive charge at that point
15.2 Induced Magnetism
 Magnets attract materials by inducing magnetism in
them; the material becomes a magnet as well.
 The side of the material facing the magnet will become
the opposite pole as the magnet.
FERROUS
NON-FERROUS
Magnetic materials
Non-magnetic materials
 IRON
 NICKEL
 COBALT
15.3 Magnetisation Methods
 A piece of steel becomes permanently magnetized when
placed near a magnet, but its magnetism is usually weak.
 It can be magnetized more strongly by stroking it with
one end of a magnet
 Most effective method: place it in a solenoid and pass a
large, direct current (d.c.) through the coil.
15.4 Demagnetisation Methods
 If a magnet is hammered, its atomic magnets are thrown
out of line and it becomes demagnetized.
 Heating a magnet to a high temperature also
demagnetize it.
 Most efficient method: place magnet inside a solenoid
connected to an alternating current (a.c.) supply.
15.5 Experiment: Field Lines Around Bar
Magnet
The magnetic field lines can be traced on a paper by a
compass needle (a tiny magnetic needle).
 The compass needle is first placed near the north pole of
magnet.
 The position of poles of needle are marked on paper.
 Then needle is moved to new position such that position
of its south pole coincides with previous position of its
north pole.
 This process is continued until the needle reaches South
Pole.
 By joining these points we get to magnetic line of force.
 Then it is placed at some other position near North Pole
and above procedure id repeated.
15.6 Magnetic Properties of Iron and Steel
IRON
 Gets magnetized faster
but loses its magnetism
as soon as inducing
magnet is removed.
 High susceptibility but
low retentivity
 Use: core in the
transformer
STEEL
 Slow to be magnetized
but retains acquired
magnetism for a long
time.
 Low susceptibility but
high retentivity.
Use: making magnets.
15.7 Permanent Magnets & Electromagnets
PERMANENT MAGNET
 Design: hard magnetic
material
 Use: for applications
where magnetism is
needed over long
periods – fridge doors
ELECTROMAGNET
 Design: Uses a solenoid
to create magnetic field
 Use: For applications
where magnetic field
needs to be turned on &
off - scrap metal moving
16. ELECTRICAL QUANTITIES
16.1 Electric Charge
 You can detect an electrostatic charge using a leaf
electroscope.
o If a charged object is placed near the cap, charges are
induced.
o The metal cap gets one type of charge (positive or
negative) and the metal stem and gold leaf get the
other type of charge so they repel each other.
PAGE 13 OF 20
CIE IGCSE PHYSICS//0625
 The conventional current is the opposite of what actually
happens.
Red=conventional
current
Green=actual
current
 There are 2 types of charges: positive and negative.
 Unlike charges attract and like charges repel.
 Electric field: region in which electric charge experiences
a force
 Conductors: materials that let electrons pass through
them.
o Metals are the best electrical conductors as they have
free electrons.
 Insulators: materials that hardly conduct at all.
o Their electrons are tightly held to atoms and hardly
move, but they can be transferred by rubbing
 The SI unit of charge is the Coulomb (C).
16.2 Electric Field Lines
Parallel
plates
Point
charge
+ve and -ve
+ve and +ve
 1̅ = 1.6 × 10−19 
 1 = 6.25 × 1018 ̅
16.5 Electromotive Force (EMF)
 The maximum voltage a cell can produce is called the
electromotive force (EMF), measured in volts.
 When a current is being supplied, the voltage is lower
because of the energy wastage inside the cell.
 A cell produces its maximum PD when not in a circuit
and not supplying current.
16.6 Potential Difference (P.D)
 Potential difference, or PD for short, is also known as
voltage.
 Voltage is the amount of energy the cell gives the
electrons it pushes out. Voltage is measured in volts (V)
and is measured by a voltmeter (connected in parallel). If
a cell has 1 Volt, it delivers 1 Joule of energy to each
coulomb of charge (J/C).



=

 =
16.3 Induced Charge
 A charge that “appears” on an uncharged object because
of a charged object nearby
 For example if a positively charged rod is brought near a
small piece of aluminum foil, electrons in foil are pulled
towards rod, which leaves the bottom of the foil with a
net positive charge.
 The attraction is stronger than repulsion because the
attracting charges are closer than the repelling ones.
16.4 Current
 Current: a flow of charge, the SI unit is the Ampere (A).
 An ammeter measures the current in a circuit and is
connected in series
 Current is a rate of flow of charge.
ℎ () =  () ×  ()
 = 
 Current follows path of least resistance
16.7 Resistance
 (Ω) =
Factors affecting resistance:
 Length
o∝
 Cross-sectional area
1
o∝
 
=
 
 Material
o Better conductor = less resistance
 Temperature
o For metal conductors higher temperature = more
resistance
o For semi-metal conductors higher temperature
PAGE 14 OF 20
CIE IGCSE PHYSICS//0625
16.8 V-I Characteristics of a Resistor
Lightdependent
resistors
 Ohm’s law states that voltage across a resistor is directly
proportional to the current through it. This is only true if
the temperature of the resistor remains constant
16.9 Electrical Energy
Lamp
Ammeter
Measure current
Voltmeter
Measure voltage
Galvanometers
Type of sensitive
ammeter; instrument
for detecting electric
current.
 1 Watt is 1J/s
  =  () ×  ()
 = 
  =  () × 
 = 
17. ELECTRICAL CIRCUITS
17.1 Circuit Diagrams
COMPONENT
Cell
Battery
DC Supply
AC Supply
Switch
Fixed resistor
Variable
resistor
SYMBOL
Bell
Fuse
Flows in one direction
Flows in both
direction
Allows current only to
flow when the switch
is closed
Restrict the flow of
current.
Used to control
current (by varying
the resistance)
Heaters
Thermistor
Magnetizing
Coil
Transformer
FUNCTION
Supplies electrical
energy. Larger
terminal (left) is
positive (+).
Supplies electrical
energy. A battery is
more than one cell.
Larger terminal (left)
is positive (+).
Resistor whose
resistance varies with
temperature
Resistor whose
resistance varies with
light intensity
Transducer which
converts electrical
energy to light
Relay
Two coils of wire
linked by an iron core.
Transformers are
used to increase and
decrease AC voltages.
Transducer which
converts electrical
energy to sound
A safety device which
will 'blow' (melt) if
current flowing
through it exceeds
specified value,
breaking circuit
An electrically
operated switch, e.g.
a 9V battery circuit
connected to the coil
can switch a 230V AC
mains circuit (the
electromagnet is used
to pull away the
contacts and vice
versa)
17.2 Series and Parallel Circuits
 The current at any point in a series circuit is the same
 The current splits at each branch in a parallel circuit so
the total current is always greater than the current in
one branch
PAGE 15 OF 20
CIE IGCSE PHYSICS//0625
 Combining resistors
o In Series:  =  + 

o In Parallel:  = 

NORMAL CLOSED RELAY
NORMALLY OPEN RELAY
⁄ + ⁄


o The combined resistance of 2 resistors in parallel is
less than that of either resistor by itself
 Advantages of putting lamps in parallel are:
o If one lamp breaks, the other still works
o Each lamp gets maximum PD
 In series: PD across the supply = PD across all the
components combined
 In parallel: Current across the source = sum of currents
in the separate branches
17.3 Potential Divider
 A potential divider divides the voltage into smaller parts.
 To find the voltage (at VOUT) we use the following
formula:

 =  × (
)

 A variable potential divider (potentiometer) is the same
as the one above but using a variable resistor; it acts like
a potential divider, but you can change output voltage.
17.4 Input Transducer
 Thermistor: input sensor and a transducer.
It is a temperature-dependent resistor. At
higher temperature there is less resistance.
 Light dependent resistor (LDR): input
sensor and a transducer. When light
intensity increases, resistance decreases.
When coil not energized,
switch is closed,
completing circuit
When coil energized,
switch is closed,
completing circuit
17.6 Diode
 A device that has an extremely high resistance in one
direction and a low resistance in the other, therefore it
effectively only allows current to flow in one direction
 Forward bias is when the diode is pointing in the
direction of the conventional current and reverse bias is
the opposite
 It can be used in a rectifier; turns AC current into DC
current.
17.7 Digital Electronics
 Analogue uses a whole range of continuous variations to
transmit a signal.
 Digital signals use only 2 states, on and off.
 Logic gates are processors that are circuits containing
transistors and other components.
17.5 Relay
 A switch operated by an electromagnet
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CIE IGCSE PHYSICS//0625
18. DANGERS OF ELECTRICITY
19. ELECTROMAGNETIC EFFECTS
18.1 Hazards
19.1 Electromagnetic Induction
 Damaged insulation: contact with the wire (live wire
especially) due to gap in the insulation causes electric
shock which can cause serious injury or shock.
 Overheating of cables: when long extension leads are
coiled up, they may overheat. The current warms the
wire, but the heat has less area to escape from a tight
bundle. This might cause a fire.
 Damp conditions: water can conduct a current, so if
electrical equipment is wet someone might get
electrocuted
FUSE
CIRCUIT BREAKER
Wire passed across a magnetic field:
 If a wire is passed across a magnetic field, a small EMF is
induced,
 If the wire forms part of a
complete circuit, the
EMF makes a current
flow and this can be
detected using a
galvanometer.
 The EMF induced in a
conductor is proportional to the rate at which the
magnetic field lines are cut by the conductor.
 The induced EMF can be increased by:
o moving the wire faster
o using a stronger magnet
o Increasing length of wire in magnetic field, e.g.
looping the wire through the field several times.
 The current and EMF direction can be reversed by:
o moving the wire in the opposite direction
o turning the magnet round so that the field direction is
reversed
 Fleming’s right-hand rule gives the current direction:
A fuse protects a circuit.
An automatic switch
Thin piece of wire which
which if current rises over
overheats and melts if
a specified value, the
current is too high. It is
electromagnet pulls the
placed on the live wire
contacts apart, breaking
before the switch. This
the circuit. The reset
prevents overheating and button is to rest
catching fire. A fuse will
everything. It works like a
have a specific current
fuse but is better because
value (e.g. 13a) so when
it can be reset.
choosing a suitable fuse
you must use the one
above minimum value but
less than maxiumum value
 Benefits of Earthing a Metal Case:
o Many electrical appliances,
have metal cases, the earth wire
creates a safe route for current
to flow through, if live wire
touches casing
o Earth terminal connected to
metal casing, so the current goes
through earth wire instead of causing
an electric shock.
o A strong current surges through earth wire because it
has very low resistance
o This breaks the fuse and disconnects the appliance
Bar magnet pushed into coil
 The induced EMF (and current) can be increased by:
o moving the magnet faster
o using a stronger magnet
o increasing the number of turns in the coil
 If the magnet is pulled away, the direction of the
induced EMF (and current) is reversed
PAGE 17 OF 20
CIE IGCSE PHYSICS//0625
 Using South pole instead of North pole reverses
direction of induced EMF (and current)
 If the magnet is held still, there is no EMF
 An induced current always flows in a direction such that
it opposes the change which produced it.
 When a magnet is moved towards a coil the pole of the
coil and magnet next to each other are the same.
 When the magnet is moved away the poles are opposite
(opposite poles attract).
 The pole-type (north or south) is controlled by the
direction in which the current is induced.
 The direction of the current is given by the right-hand
grip rule:
19.3 Transformers
 AC currents can be increased or decreased by using a
transformer.
 Consists of a primary coil, a secondary coil and an iron
core.
 The iron core gets magnetized by the incoming current
and this magnetism then creates a current in the leaving
wire.
 The power is the same on both sides (assume= 100%
efficiency).
 You can figure out number of coils and the voltage with:
     
=
 
   


=


  ×  
=   ×  
 The fingers point in the conventional current direction
and the thumb gives the North Pole.
19.2 A.C. Generator
 The oil is made of insulated copper wire and is rotated
by turning the shaft; the slip rings are fixed to the coil
and rotate with it.
 The brushes are 2 contacts which rub against the slip
rings and keep the coil connected to the outside part of
the circuit, usually made of carbon.
 When the coil is rotated, it cuts magnetic field lines, so
an EMF is generated, which makes a current flow.
 Each side of the coil travels upwards then downwards
then upwards etc. so the current flows backwards then
forwards then backwards etc. so it is an alternating
current.
 The current is maximum when the coil is horizontal since
field lines are being cut at the fastest rate and 0 when
the coil is vertical, since it is cutting NO field lines.
 The EMF can be increased by:
o increasing the number of turns on the coil
o increasing the
area of the coil
o using a stronger
magnet
o rotating the coil
faster
 ×  =  × 
 When magnetic field is
changed across the
primary coil by
connecting it with A.C. an
e.m.f. induces across the
secondary coil.
 The iron core channels the alternating field through the
secondary coil, inducing an alternating e.m.f. across it.
 A step-up transformer increases the voltage and a stepdown transformer decreases it.
 Transformers used to make high voltage AC currents.
 Since power lost in a resistor  =  × , having a
lower current will decrease the power loss.
 Since transmission cables are many kilometres long they
have a lot of resistance, so a transformer is used to
increase the voltage and decrease the current to
decease power lost.
 The advantages of high-voltage transmission:
o less power lost
o thinner, light, and cheaper cables can be used since
current is reduced
19.4 Electromagnetic Effect of a Current
Magnetic field around a
current carrying wire
PAGE 18 OF 20
Magnetic field around a
current carrying solenoid
CIE IGCSE PHYSICS//0625
 Increasing the current increases the strength of the field
 Increasing the number of turns of a coil increases the
strength.
 Reversing the current direction reverses the magnetic
field direction (right-hand rule).
 Magnetic effect of current is used in a relay and a circuit
breaker
19.5 Force on a Current-Carrying Conductor
 If a current carrying conductor is in a magnetic field, it
warps the field lines.
 The field lines from the magnet want to straighten out
naturally.
 This causes a catapult like action on the wire creating a
force
 If you reverse current, you will reverse direction of force
 If you reverse direction of field, you will reverse direction
of force.
 The direction of the force, current or magnetic field is
given by Fleming’s left-hand rule:
19.6 D.C. Motor
 When a current-carrying coil is in a magnetic field, it
experiences a turning effect.
 A DC motor runs on a direct current.
 The coil is made of insulated copper wire and is free to
rotate between the poles of the magnet.
 The commutator (split-ring) is fixed to the coil and
rotates with it.
 When the coil overshoots the vertical, the commutator
changes direction of the current through it, so the forces
change direction and keep the coil turning.
 The brushes are two contacts which rub against the
commutator and keep the coil connected to battery,
usually made of carbon
 The max. turning effect is when the coil is horizontal.
 There is no force when the coil is vertical but it always
overshoots this position
TURNING EFFECT
REVERSING ROTATION CAN
INCREASED BY:
BE DONE BY:
 Increasing the current
 Reversing the battery
 Using a stronger magnet  Reversing the poles
 Increasing length of coils:
o Increasing no. of coils
o Increasing area of coil
20. RADIOACTIVITY
20.1 Direction of Radioactivity
 Background radiation: small amount of radiation around
us all time because of radioactive materials in the
environment. It mainly comes from natural sources such
as soil, rocks, air, building materials, food and drink –
and even space.
Geiger-Müller (GM) tube (detects ,  and )
 The ‘window’ is thin enough for alpha particles to pass
through.
 If an alpha particle enters the tube, it ionizes gas inside.
 This sets off a high-voltage spark across the gas and a
pulse of current in the circuit.
 A beta particle or gamma radiation has the same effect.
 It can be connected to a rate meter (tells the counts per
seconds) or a scaler (tells total number of particles or
bursts of gamma radiation)
PAGE 19 OF 20
CIE IGCSE PHYSICS//0625
20.2 Characteristics of 3 Kinds of Emissions
 Radioactive emissions occur randomly over space & time
ALPHA ()
BETA () GAMMA ()
Helium
One high
Electronucleus (2
NATURE
speed
magnetic
protons and
electron
radiation
2 electrons)
CHARGE
+2
-1
none
Stopped by Stopped by Only reduced
PENETRATION
paper
aluminum
by lead
EFFECT FROM
Very
Not
Deflected
FIELDS
deflected
deflected
IONIZING
Very strong
Weak
Very weak
EFFECT
1⁄   ℎ 9⁄   ℎ
  ℎ
SPEED
10
10
20.3 Radioactive Decay
 Radioactive decay: A radioisotope (unstable
arrangement of neutrons and protons) is altered to
make a more stable arrangement.
 The parent nucleus becomes a daughter nucleus and a
particle (decay products).
Alpha decay:
 An element with a proton number 2 lower and nucleon
number 4 lower, and an alpha particle is made (2p + 2n)
e.g. Radium-226 nucleus → Radon-222 + helium-4 nucleus
226
222
4
88Ra → 86Rn + 2He
Beta decay:
 A neutron changes into a proton, an electron and an
antineutrino so an element with the same nucleon
number but with a proton number 1 higher e.g.
e.g. iodine-131 → xenon-131 + antineutrino + beta particle
131
131
0
0
53 → 54 + −1β + 0v
Gamma emission:
 Gamma emission by itself causes no change in mass
number or atomic number; they just emit energy
 Some isotopes do not change in mass or atomic number
however they emit energy as their particles rearrange
themselves to become more stable
 Kept away from the body and not pointed at people
 Left out of its container for as short a time as possible
20.6 Atomic Model
Atoms consist of:
 Nucleus: central part of atom made of protons
(positively charged) and neutrons. These two types of
particles are called nucleons. They are bound together
by the strong nuclear force.
 Electrons: almost mass-less particles which orbit nucleus
in shells
20.7 Rutherford’s Experiment
 Thin gold foil is bombarded with alpha particles, which
are positively charged.
 Most passed straight through, but few were repelled so
strongly that they were bounced back or deflected at
large angles.
 Rutherford concluded that the atom must be largely
empty space, with its positive charge and most of its
mass concentrated in a tiny nucleus.
20.8 Nucleus
 The nucleus is composed of
protons and neutrons.
 Proton number: number of protons in an atom
 Nucleon number: the number of nucleons (protons +
neutrons) in an atom
20.9 Isotopes
 Isotope: atoms of the same element that have different
numbers of neutrons e.g. Carbon 12 and Carbon 14.
 There are non-radioactive isotopes and radio-isotopes.
20.4 Half Life
 Radio isotopes are unstable atoms, which break down
 Half-life of a radioisotope: is the time taken for half the
giving radiation
nuclei present in any given sample to decay.
 Medical use: cancer treatment (radiotherapy) – rays kill
 Some nuclei are more stable than others
cancer cells using cobalt-60
 Industrial use: to check for leaks – radioisotopes
20.5 Safety Precautions
(tracers) added to oil/gas. At leaks radiation is detected
 Radioactive material is stored in a lead container
using a Geiger counter.
 Picked up with tongs, not bare hands
 Archaeological use: carbon 14 – used for carbon dating
PAGE 20 OF 20
TABLE OF CONTENTS
3
CHAPTER 1
4
CHAPTER 2
5
CHAPTER 3
6
CHAPTER 4
6
CHAPTER 5
7
CHAPTER 6
9
CHAPTER 7
11
CHAPTER 8
12
CHAPTER 9
14
Characteristic & Classification of Living Organisms
Organization of the Organism
Movement In and Out of Cells
Biological Molecules
Enzymes
Plant Nutrition
Human Nutrition
Transport in Plants
Transport in Animals
CHAPTER 10
Diseases & Immunity
CIE IGCSE BIOLOGY//0610
15
CHAPTER 11
16
CHAPTER 12
16
CHAPTER 13
17
CHAPTER 14
Gas Exchange in Humans
Respiration
Excretion in Humans
Coordination & Response
21 Drugs
CHAPTER 15
22
CHAPTER 16
27
CHAPTER 17
Reproduction
Inheritance
28 Variation & Selection
CHAPTER 18
29
CHAPTER 19
Organisms & their Environment
31 Biotechnology & Genetic Engineering
CHAPTER 20
33 Human Influences on Ecosystems
CHAPTER 21
PAGE 2 OF 35
CIE IGCSE BIOLOGY//0610
1. CHARACTERISTICS AND CLASSIFICATION OF
LIVING ORGANISMS
1.1 Characteristics of Living Organisms
 Movement: action by an organism or part of an
organism causing a change of position or place
 Respiration: the chemical reactions that break down
nutrient molecules in living cells to release energy
 Sensitivity: ability to detect or sense changes in the
environment (stimuli) and to make responses
 Growth: permanent increase in size and dry mass by an
increase in cell number or cell size or both
 Reproduction: processes that make more of the same
kind of organism
 Excretion: removal from organisms of toxic materials,
the waste products of metabolism (chemical reactions in
cells including respiration) and substances in excess of
requirements
 Nutrition: taking in of nutrients which are organic
substances and mineral ions, containing raw materials or
energy for growth and tissue repair, absorbing and
assimilating them
1.2 Concept & Use of a Classification System
 Organisms can be classified into groups by the features
that they share
 Classification systems aim to reflect evolutionary
relationships (change of adaptive features of a
population over time, as a result of natural selection)
 Species: organisms which can reproduce successfully
 Classification is traditionally based on studies of
morphology and anatomy
 Morphology: the overall form and shape of their bodies
e.g. wings or legs
 Anatomy: the detailed body structure determined by
dissection
 Binomial system: a system of naming species in which
the scientific name of an organism is made up of two
parts showing the genus (starting with a capitol letter)
and species (starting with a lower case letter), written in
italics when printed (therefore underlined when written)
e.g. Homo sapiens
KING PHILIP CAME OVER FOR GOOD SPAGHETTI
 Kingdom, Phylum, Class, Order, Family, Genus, Species
 Kingdom  Species = Similarity increases
 DNA is the chemical from which chromosomes are made
 Each DNA molecule is made up of strings of smaller
molecules containing four bases
 Biologists compare the sequences of the bases in the
DNA of organisms from two different species
 The more similar the base sequence, the more closely
related the species are to one another
 Organisms which share a more recent ancestor have
base sequences in DNA that are more similar than those
that share only a distant ancestor
 The sequences of bases in DNA and of amino acids in
proteins are used as a more accurate means of
classification (cladistics)
1.3 Kingdoms
 Animal: Multi-cellular ingestive heterotrophs (eat living
organisms)
 Plant: Multi-cellular photosynthetic autotrophic (make
their own food) organism with a cellulose cell wall.
 Fungi: Single celled or multi cellular heterotrophic
organism with cell wall not made of cellulose, spread by
spreading of spores in moist/dark/warm environment,
saprotrophs (feed off dead organisms) or parasites
 Prokaryotes: Single celled organism with no true nucleus
 Protocist: Single celled organism with a nucleus
1.4 Vertebrates
MR FAB
 Mammals
o Fur/hair on skin
o Can live on land and in water
o 4 legs
o Lungs to breathe
o Give birth to live young
 Reptiles:
o Scales on skin
o Usually 4 legs
o Lungs to breathe
o Hard eggs
 Fish:
o Wet scales
o External fertilization and soft eggs
o Gills to breathe
 Amphibians:
o Smooth, moist skin
o External fertilization and soft eggs
o Gills/lungs to breathe so can live on land and in water
o 4 legs
PAGE 3 OF 35
CIE IGCSE BIOLOGY//0610
 Birds
o Feathers on body and scales on legs
o Have 2 legs and 2 wings
o Lungs to breathe
o Hard eggs
1.7 Viruses and Bacteria
VIRUS
Protein coat
1.5 Arthropods (Invertebrates with Legs)
CAMI
 Crustaceans: (e.g. crabs)
o Have an exoskeleton
o 1 pair of compound eyes
o 2 body segment – cephalothorax and abdomen
o More than four pairs of legs
o 2 pairs of antennae sensitive to touch and chemicals
 Arachnids: (e.g. spiders)
o 2 body segment – cephalothorax and abdomen
o Four pairs of legs
o Pair of chelicerae to hold prey
o Two pedipalps for reproduction
o Simple eyes
 Myriapods: (e.g. centipede)
o Segmented body
o Additional segments formed
o One pair of antennae
o 70+ pairs of legs – 1 or 2 pairs on each segment
o Fused head and thorax and segmented abdomen
o Simple eyes
 Insects: (e.g. bees)
o 3 body segments – head, thorax and abdomen
o 3 pairs of legs
o 1 pair of antennae
o 1 or 2 pairs of wings
o Compound and simple eyes
1.6 Classifying Plants
 Ferns:
o Do not produce flowers
o They are plants with roots, stems and leaves
o Have leaves called fronds
o Reproduce by spores
 Flowering plants:
o They are plants with roots, stems and leaves
o Reproduce sexually by means of flowers and seeds
o Seeds are produced inside the ovary in the flower
Monocotyledons
Dicotyledons
 One cotyledon
 Two cotyledons
 Parallel veins
 Veins netlike
 Fibrous root
 Taproot present
 Floral parts in 3s
 Floral parts in 4s or 5s
COVERED BY
CELL
No
MEMBRANE
CYTOPLASM
No
GENETIC
DNA or RNA –
MATERIAL
only a few genes
LIVING OR
Non-living unless
NOT?
in host
 Two examples of virus structure
BACTERIA
Cell wall
Yes
Yes
DNA – enough for
several 100 genes
Living
1.8 Dichotomous Keys
 Dichotomous key: uses visible features to classify
organisms. It is which gives you a choice of two features
and you follow the one that applies: each choice leads
to another choice until the organism is narrowed down
to its genus and finally species.
2. ORGANIZATION OF THE ORGANISM
2.1 Cell structure and Organization
 All living things are made of cells.
 All typical cells have:
o Cell membrane: differentially or partially permeable
to allow certain substances to enter and leave the cell.
o Cytoplasm: where chemical reactions take place
o Nucleus: contains DNA and controls the cell
o Mitochondria: organelle where aerobic respiration
happens
o Ribosome: makes protein and can be found floating
within the cytoplasm
 A typical animal cell (e.g. the liver cell) has all above
 Only plant cells have:
o Vacuole: stores food & water & helps to maintain
shape of cell
o Cell wall: rigid to keep shape of cell
o Chloroplasts: contain chlorophyll, which absorbs light
energy for photosynthesis
PAGE 4 OF 35
CIE IGCSE BIOLOGY//0610
 A typical plant cell (e.g. the palisade cell) has all the
above things.
2.2 Levels of Organization
CELL
RED
BLOOD
CELL
FUNCTION
Transport
of oxygen
MUSCLE
CELL
Contracts
to get
structures
closer
together
CILIATED
CELL
Move and
push
mucus
Absorb
ROOT
minerals
HAIR CELL
and water
XYLEM
VESSEL
Transport
water and
support
plant
PALISADE
CELL
Photosynthesizes
ADAPTATION(S)
 Biconcave
shape
 No nucleus
 Flexible
 Has
haemoglobin
 Long
 Many protein
fibres in
cytoplasm to
shorten cell
when energy
available
 Tiny hairs
called cilia
 Elongated
shape for
more surface
area
 No cytoplasm
so water
passes freely
 No cross walls
so cells
connect to
form tube
 Lignin makes it
strong and
waterproof
 Regular shape
so many can
fit in a small
space
 Many
chloroplasts
DIAGRAM
 Organelle: a specialized part of a cell that has its own
function, e.g. the nucleus
 Cell: the smallest part of a living structure that can
operate as an independent unit e.g. red blood cell
 Tissue: a group of cells with similar structures, working
together to perform a shared function e.g. muscle tissue
 Organ: a structure made up of a group of tissues,
working together to perform specific functions e.g. heart
 Organ system: group of organs with related functions,
working together to perform body functions e.g.
respiratory system
2.3 Size of Specimens
 =
    
=
=
    
3. MOVEMENT IN AND OUT OF CELLS
3.1 Diffusion
 This is the movement of molecules from a region of high
concentration to a region of low concentration down the
concentration gradient.
 This results in random movement of molecules until
equilibrium is reached
 The diffusion of gases and solutes is important as
without it, molecules which are needed for life, for
example glucose and oxygen for respiration, would not
be able to get to the places they are needed. Water is
needed as a solvent
 Factors influencing faster diffusion:
o Larger concentration gradient
o Higher temperature
o Smaller surface area
3.2 Osmosis
 Movement of water molecules from a region of high
water potential to a region of low water potential,
through a partially permeable membrane
 Conc. of solute outside cell = conc. inside cell → no
change in size
 Conc. of solute outside cell > conc. inside cell → cell
shrinks (Plasmolysis)
 Conc. of solute outside cell < conc. inside cell → cell
swells (Turgid)
 In animals:
o Increasing solute concentration inside of cell can
cause cell to explode as a result of it having too much
water, crenation.
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 In plants:
o Increasing solute concentration inside of cell causes
cell to become turgid, vacuole fills up.
o Decreasing solute concentration inside of cell causes
cell to become flaccid, losing water and vacuole gets
smaller. Cell body shrinks, pulling away from cell wall
3.3 Active Transport
 Movement of particles through a cell membrane, from a
region of lower concentration to a region of higher
concentration against a concentration gradient, using
energy released during respiration
 Active transport is needed when an organism wants to
optimize the amount of nutrients it can take up - ion
uptake by root hairs and uptake of glucose by epithelial
cells of villi.
 Two strands coiled together to form a double helix
 Each strand contains chemicals called bases
 Cross-links between strands are formed by pairs of bases
 The bases always pair up in the same way:
o A and T
o C and G
5. ENZYMES
 Catalyst: a substance that speeds up a chemical reaction
and is not changed by the reaction
 Enzymes: proteins that function as biological catalysts
 Enzymes lowers amount of energy needed for reaction
to take place
 Enzyme lowers the activation energy needed for reaction
to take place
 Lock and key theory:
4. BIOLOGICAL MOLECULES
 Carbohydrates: made from Carbon, Hydrogen and
Oxygen (CHO)
 Fats and oils: made from Carbon, Hydrogen and Oxygen
(CHO)
 Proteins: made from Carbon, Hydrogen, Oxygen,
Nitrogen and sometimes Sulfur (CHON[S])
BASIC UNITS
LARGER MOLECULES
(MONOMERS)
(MACROMOLECULES)
Simple sugars
Starch and glycogen
Fatty acids and glycerol
Fats and oils
Amino acids
Proteins
4.1 Chemical Tests
 Starch: Add few drops of iodine, +ve result = blue-black
colour
 Reducing sugars: Add Benedict’s reagent, then mixture
is heated in water bath for 2 to 3 minutes. +ve result =
brick-red precipitate, -ve result = remains blue
 Proteins: Add few drops of Biuret reagent, +ve result =
mauve colour
 Fats: Emulsion test; ethanol is added to mixture, and this
is poured into a test tube with an equal amount of
distilled water, +ve result = milky-white emulsion
 Vitamin C: Decolourisation of DCPIP shows that a
vitamin C is probably present.
4.2 Structure of a DNA
 Chromosomes are made of a molecule called DNA
 Each chromosome is a very long molecule of tightly
coiled DNA
 Substrate: the molecule(s) before they are made to
react
 Product: the molecule(s) that are made in a reaction
 Catabolic reaction: molecules are broken down
 Anabolic reaction: molecules are combined
5.1 Effect of Temperature on Enzymes
 Enzymes have an optimum temperature: the
temperature at which they work best giving the fastest
reaction ≈ 37°C in animals
 When temperature increases, molecules move faster so
collide with an enzyme in less time
 Having more energy makes them more likely to bind to
active site.
 If temperature is too high, enzyme molecules vibrate too
vigorously and enzyme is denatured; it loses its shape
and will no longer bind with a substrate.
 When the temperature is too low there is not enough
kinetic energy for the reaction so it reacts too slowly.
5.2 Effect of pH on Enzymes
 Enzymes are sensitive to pH
 Some enzymes work best in an acid and others in an
alkaline
 Enzymes work best at their optimum pH
 If the pH is changed then the enzyme will denature and
will no longer fit with substrate- no reaction takes place
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5.3 Graphs for Changes in Enzyme Activity
EFFECT OF TEMPERATURE
EFFECT OF PH
 Warmed in ethanol until leaf is colourless to extract
chlorophyll, which would mask observation
 Dipped in water briefly: to soften leaf
 Leaf is placed on a white tile and iodine is added. If
starch is present, colour will be blue-black and if absent,
it will remain orange
5.4 Enzymes and their Uses
 Seeds to germinate: the enzymes turn insoluble food
stores to soluble.
 Biological washing powders: enzymes are added to
washing powders to help remove stains for example:
o Lipase for lipids from fatty foods and greasy
fingerprints
o Protease for proteins from blood stains
 Food industry:
o Isomerase converts glucose to fructose which is
sweeter, so less is needed to give a sweet taste
o Pectinase helps break down cell walls in fruit juice
production so it increases yield, lowers viscosity and
reduces cloudiness
6.2 Light Is Necessary for Photosynthesis
 Destarch the plant by keeping it in darkness for 48hrs
 Place a stencil over part of a leaf
 Place the leaf in sunlight for 4-6 hours
 Remove the stencil and test for starch
 +ve result = parts which received light turn black
 -ve result = parts which didn’t receive light remain
yellow/brown
6. PLANT NUTRITION
 Photosynthesis: process by which plants manufacture
carbohydrates from raw materials using energy from
light.
ℎ + ℎℎ
  +  →
 + 
ℎ + ℎℎ
62 + 62  →
6 12 6 + 62
 The carbon dioxide diffuses through the open stomata of
the leaf of a plant and water is taken up through roots.
 Chlorophyll is a dye, which traps light energy and
converts it into chemical energy for the formation of
carbohydrates and their subsequent storage.
6.1 Chlorophyll Is Necessary for
Photosynthesis
 Take a potted plant with variegated (green and white)
leaves.
 Destarch the plant by keeping it in complete darkness for
about 48 hours.
 Expose the plant to the sunlight for a few days.
 Leaf boiled in water for 2 minutes to break down cell
walls, denature enzymes and allow for easier
penetration by ethanol.
6.3 Carbon Dioxide is Necessary for
Photosynthesis
 Take two destarched potted plants.
 Cover both the plants with bell jars and label them as A
and B.
 Inside A, keep NaHCO3 (sodium bicarbonate). It produces
CO2.
 Inside B, keep NaOH (Sodium hydroxide). It absorbs CO2.
 Keep both the set-ups in the sunlight for at least 6 hours.
 Perform the starch test on both plants.
B
A
 The leaves of Plant A will turn black after the starch test
 The leaves of Plant B will remain orange/brown after
starch test
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6.4 Limiting Factors
6.6 Leaf Structure
•Limiting factor: something present in the environment in
such short supply that it restricts life processes.
Light intensity
 As the amount of light increases,
the rate of photosynthesis
increases (a-b)
 The limiting factor is light
 Increasing the amount of light
after a certain point has no effect
on the rate (c)
 The limiting factor is now carbon
dioxide or temperature
Carbon dioxide concentration
 As the amount of carbon dioxide
increases, the rate of
photosynthesis increases (a-b)
 The limiting factor is carbon
dioxide
 Increasing amount of carbon
dioxide after a certain point has
not effect on rate (c)
 The limiting factor is now light or
temperature (warmth)
Temperature
 As temperature increases, the rate
of photosynthesis increases until it
reaches optimum temperature
40°c (a)
 The limiting factor is the
temperature
 Increasing the temperature above
40°c will cause the enzymes to
denature (b)
 This will decrease rate of
photosynthesis
C
B
A
C
B
A
A
B
 Cuticle: waxy layer that prevents water loss from top of
the leaf
 Epidermis: transparent cell that allows sunlight to pass
through to the palisade cell
 Palisade: found at the top of the cell and contains many
chloroplasts which absorbs sunlight.
 Spongy mesophyll layer: irregularly shaped cells which
create air spaces to allow gaseous exchange to take
place; do not contain many chloroplasts
 Vascular Bundle: made up of xylem and phloem
 Xylem: vessel which transports water and dissolved
minerals and has lignified walls made of cellulose
 Phloem: vessel which transports nutrients
 Stomata: little holes that opens and closes to allow
gaseous exchange to take place. The stomata close to
prevent water loss and open to let gases come in and
out. When guard cells lose water, the stoma close (at
night), while the stoma open when guard cells gain
water & swell (during the day).
6.5 Glasshouse Systems
To increase the crop yield, farmers control the limiting
factors:
 CO2 enrichment: paraffin is burnt to increase CO2
concentration by three times the original amount and
doubling the yield
 Optimum temperature: thermostatically controlled
heaters make the temperature right for enzymes to work
 Optimum light: light has a high intensity for more
photosynthesis, the correct wavelengths (red and blue
not green) and duration controls production of fruit
6.7 Xylem
 Unidirectional vessel which
transports water and dissolved
minerals.
 Walls are made out of
waterproof lignin.
 Water moves up due to
transpiration and osmosis
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6.8 Phloem
7.1 Malnutrition
 Bidirectional vessel
 Contains sieve
elements which allow
sugars to pass from one
cell to next downwards
 Contains companion cells
which provide energy for active
transport of sugars all over
plant.
 Translocation moves organic molecules (sugars, amino
acids) from source to sink.
 Phloem vessels still have cross walls called sieve plates
that contain pores.
 Companion cells actively load sucrose into the phloem.
 Water follows high solute in phloem by osmosis. A
positive pressure potential develops moving mass of
phloem sap forward.
 Phloem still contains small amount of cytoplasm along
the walls but the organelle content is greatly reduced.
 Companion cells actively unload (ATP used) the organic
molecules
 A condition caused by eating an unbalanced diet. Several
forms:
o Overnutrition: balanced diet but eating too much of
everything
o Undernutrition: having too little food
o Eating foods in incorrect proportions
6.9 Mineral Requirements
NITROGEN
MAGNESIUM
 Needed for protein
 Needed for chlorophyll
synthesis
synthesis
 Deficiency: small plant,
 Deficiency: plant lack
slow growth, top leaves
chlorphyll, leaves yellow
pale, bottom leaves
but normal roots
dead and roots slightly
affected
 Nitrogen fertilizers: provide nitrogen in the form of
nitrate ions, nitrite ions or ammonium ions. But using
fertilisers can lead to eutrophication, which is when the
fertiliser is transported by rain and leaches into stagnant
water e.g. pond or river
7. HUMAN NUTRITION
 Balanced Diet: getting all the right nutrients in correct
proportions
 Diet related to age/sex/activity:
o Children Below 12: Require more calcium
o Teenagers: Highest calorie Intake
o Adults: Balanced meal with less calories
o Pregnant Women: more iron, calcium and folic acid
o Males: Generally, require more energy
7.2 Effects of Malnutrition
 Starvation: losing strength & finally dying because of
lack of food
 Coronary heart disease: eating too much fats which are
rich in saturated fatty acids and cholesterol, may lead to
heart attack
 Constipation: lack of roughages in food causes
constipation because roughages are indigestible and
form bulks. Friction between bulks and walls of intestine
stimulate the peristalsis
 Obesity: Eating too much fats and carbohydrates leads
to their storage in storage in the body mainly in the
forms of fats and causing an increase in body weight.
This can cause; heart attack, stroke, joint pain, mobility
impairment, high blood pressure
7.3 Uses
NUTRIENT
CARBOHYDRATES
FATS
PROTEINS
VITAMIN C
VITAMIN D
CALCIUM
IRON
FIBER
WATER
USES
Energy
Source of energy, building materials,
energy store, insulation, buoyancy,
making hormones
Energy, building materials, enzymes,
haemoglobin, structural material
(muscle), hormones, antibodies
Protect cells from ageing, production of
fibres
Absorption of calcium
Development and maintenance of
strong bones and teeth
Making haemoglobin
Provides bulk for faeces, helps peristalsis
Chemical reactions, solvent for transport
7.4 Deficiencies
 Vitamin C: Scurvy; loss of teeth, pale skin & sunken eyes
 Vitamin D: Rickets; weak bones and teeth
 Calcium: Rickets; weak bones and teeth, also poor
clotting of blood, spasms
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 Iron: Anaemia: Fatigue (less iron → less haemoglobin →
less oxygen transported → less respiration → less
energy)
7.5 Human Alimentary Canal
 Large intestine: tube shaped organ composed of two
parts:
o Colon: organ for absorption of minerals and vitamins,
and reabsorbing water from waste to maintain body’s
water levels
o Rectum: where faeces are temporarily stored
 Anus: ring of muscle which controls when faeces is
released.
 Ingestion: taking substances (e.g. food, drink) into the
body through the mouth.
 Egestion: passing out of food that has not been digested,
as faeces, through the anus.
7.6 Diarrhoea
 Digestion: the break-down of large, insoluble food
 Diarrhoea: when not enough water is absorbed from the
molecules into small, water soluble molecules using
mechanical and chemical processes
faeces
 Mouth: contains teeth used for mechanical digestion,
 To cure this is to give oral rehydration therapy
area where food is mixed with salivary amylase & where
 One of these this infectious by a bacterium causing the
ingestion takes place
diseases cholera (spreads rapidly)
 Salivary glands: produce
saliva  The cholera bacterium produces a toxin that causes
which contains amylase
secretion of chloride ions into the small intestine,
and helps food slide
causing osmotic movement of water into the gut,
down oesophagus
causing diarrhoea, dehydration and loss of salts from the
 Oesophagus: tubeblood
shaped organ which uses
peristalsis to transport
food
7.7 Teeth
from mouth to stomach
INCISOR
CANINE
PREMOLAR
MOLAR
 Stomach: has sphincters to
control movement into and
also has pepsin (a protease) to
break down proteins into peptides, it also kills bacteria
with hydrochloric acid. They also have elastic walls.
 Small intestine: tube shaped organ composed of two
Blunt
Blunt for
Rectangular
Sharpparts the:
pointed for
chewing and chewing and
shape, sharp
o Duodenum: fats are emulsified by bile, and digested
crushing.
holding and
crushing
for cutting
by pancreatic lipase to form fatty acids and glycerol.
Two roots
and biting
cutting
Pancreatic amylase and trypsin (a protease) break
down starch and peptides into maltose and amino
7.8 Structure of a Tooth
acids
 Enamel: the strongest tissue in the body made from
o Ileum: Maltase breaks down maltose to glucose. This
calcium salts
is where absorption takes place; adapted by having

Cement: helps to anchor tooth
villi and microvilli.
 Pulp cavity:
 Pancreas: produces pancreatic juice which contains
contains toothamylase, trypsin and lipase and hydrogencarbonate.
producing cells,
 Liver: produces bile, stores glucose as glycogen,
blood vessels, and
interconverting them to keep glucose concentration
nerve endings which
constant. Also carries out interconversion of amino acids
detect pain.
(transamination), deamination and removal of old red

Dentine: calcium salts
blood cells and storage of their iron. Also site of
deposited on a framework
breakdown of alcohol and other toxins.
of collagen fibres
 Gall bladder: stores bile from liver
Neck:
in between crown and root, it is the gums
 Bile: produced by liver and stored in gall bladder, its role
is to emulsify fats, to increase surface area for the action
of enzymes.
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 Vein: delivers absorbed products to liver via hepatic
portal vein.
 Gland: produces enzymes
 Lacteal: absorbs fatty acid and glycerol
 Epithelium: only one cell thick for faster transport. The
cells of the epithelium are folded to form microvilli.
 Small intestine and colon absorb water
o The small intestine absorbs 5–10 dm3 per day
o The colon absorbs 0.3–0.5 dm3 per day
7.9 Tooth Decay
8. TRANSPORT IN PLANTS
7.10 Prevention
 Eating food with low sugar content
 Regular and effective teeth brushing to remove plaque
 Finishing a meal with a crisp vegetable and a glass of
water
7.11 Chemical Digestion
 Where enzymes are used to break down large insoluble
substances such as proteins into smaller soluble
substances like amino acids so that they can be
absorbed.
 Amylase: breaks down starch into maltose, it is
produced in the pancreas (but also in the salivary gland)
 Protease: breaks down proteins to peptides (done by
pepsin) then into amino acids (done by trypsin). Pepsin
comes from the stomach and trypsin comes from the
pancreas.
 Lipase: breaks down lipids into fatty acids and glycerol,
produced by the pancreas.
 Hydrochloric acid in gastric juice:
o Denaturing enzymes in harmful microorganisms in
food
o Giving the optimum pH for pepsin activity
8.1 Xylem and Phloem
 Functions of xylem and phloem
o To transport substances from source, where they are
taken in or made, to the sinks, where they are used
o To support the stem
Stem
Root
Leaf
8.2 Root Hair Cell
7.12 Absorption
 Movement of digested food molecules through wall of
the intestine into the blood or lymph.
 The small intestine is the region for absorption of
digested food.
 The small intestine is folded into many villi which
increase the surface area for absorption. One villus will
have tiny folds on the
cells on its outside called
microvilli.
 More surface area
means more absorption
can happen
 Capillary: transports
glucose and amino acids
 Function: to absorb water and minerals from the soil
 They have an elongated shape for more surface area
which increases the rate of absorption of water by
osmosis and ions by active transport
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8.3 Pathway Taken By Water
8.7 Translocation
 Water enters root
hair cell from
moist soil via
osmosis because
water potential is
higher in soil than
in cytoplasm.
 Water passes
through the cortex
cells by osmosis
but mostly by
“suction”.
 Water and
minerals are forced to cross the endodermis.
 Water enters xylem then leaves when it gets to
mesophyll cells
 Movement of sucrose and amino acids in phloem; from
regions of production (sources) to regions of storage or
to regions of utilization in respiration or growth (sinks).
 Translocation in different seasons:
o Spring: sucrose transported from stores in roots to
leaves
o Summer & early autumn: sucrose goes from
photosynthesizing leaves to root stores,
9. TRANSPORT IN ANIMALS
 Circulatory system: system of tubes (veins, capillaries,
arteries) with a pump (heart) and valves (in heart and
veins) to ensure one-way flow of blood.
9.1 Transport Systems
 Transpiration: evaporation of water at surfaces of the
mesophyll cells followed by loss of water vapour from
plant leaves, through stomata.
 Water leaves mesophyll cells, into air spaces created by
irregular shape of spongy mesophyll cells, then diffuses
out of the stomata.
 Wilting: occurs if water loss is greater than water uptake
– cells become flaccid, tissues become limp and plant no
longer supported
 Single circulation system (fish):
o Two heart chambers
o Blood absorbs oxygen in gills
o Released in body cells then back to heart
 Double circulation system:
o Four heart chambers
o Blood passes through heart twice
o Oxygenated in lungs, to heart, to body, back to heart
o Advantage: delivers greater blood flow rate to tissues
around the body as the heart pumps the oxygenated
blood to it from the lungs
8.5 Uptake of Water
9.2 The Heart
8.4 Transpiration
 Caused by water loss in leaves which lowers its water
potential
 Water moves from xylem to leaf tissues via osmosis
 Water moves up the stem in the xylem due to tension
(because of cohesion of water molecules to each other)
caused by water loss from the leaves
 Ends with the gain of water through roots
 This upward flow of water is called the transpiration
stream
Bicuspid
8.6 Factors Affecting Rate of Transpiration
 Temperature: higher temperatures increase waterholding capacity of air and increases transpiration rate
 Humidity: low humidity increases water potential
gradient between leaf and atmosphere  increasing
transpiration rate
 Light intensity: high light intensity causes stomata to
open (to allow more photosynthesis) which causes
increase in transpiration
Septum
 Right atrium: collect deoxygenated blood & pump it to
right ventricle
 Right ventricle: pumps deoxygenated blood to lungs
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 Pulmonary artery: carries deoxygenated blood from
right ventricle to lungs
 Septum: separates left and right sides of the heart
 Pulmonary vein: carry oxygenated blood from lungs to
left atrium
 Left atrium: collect oxygenated blood and pump it to left
ventricle
 Left ventricle: pumps oxygenated blood to the body via
the aorta
 Aorta: carries oxygenated blood from left ventricle to
rest of body
 Tricuspid and bicuspid valves: prevent backflow of
blood into the atria when ventricles contract (atria
ventricular valves)
 Pulmonary and aortic valves: prevent backflow of blood
from the arteries into the ventricles (semi-lunar valves)
9.3 Cardiac Cycle
Cardiac diastole:
all chambers are
relaxed, and blood
flows into the
heart
Atrial systole,
Atrial diastole,
ventricular
ventricular
diastole: atria
systole: after atria
contract, pushing relax, ventricles
blood into the
contract, pushing
ventricles
blood out of heart
 Physical activity makes the heart beat more quickly and
more deeply, for an increased circulation of blood so
that more oxygen and glucose can get to the muscles.
9.4 ECG Trace
 The electrical activity of the heart can be monitored
by the electrocardiogram, pulse rate and listening to
the sounds of the valves closing
 Physical activity makes the heart beat more quickly
and more deeply, for an increased circulation of
blood so that more oxygen and glucose can get to the
muscle
9.5 Coronary Heart Disease
 Coronary artery becomes blocked, interrupting the
supply of blood to the heart muscle.
 The heart muscle cells are deprived of oxygen & glucose,
and poisonous wastes such as lactic acid build up.
 Part of the heart muscle stops contracting, causing a
heart attack
 Caused by stress, smoking, poor diet, poor lifestyle &
genetically
 Can be prevented by not smoking, avoiding fatty food
and exercising regularly
 Treated by aspirin and surgery (stents, angioplasty and
by-pass)
9.6 Arteries, Veins and Capillaries
VESSEL
STRUCTURE
 Elastic walls expand and
relax as blood is forced
out; causes pulse
 Transport
high pressure  Thick walls withstand
ARTERY
blood away
high pressure
from heart
 Rings of muscle narrow
or widen artery to
control blood flow.
 Valves prevent backflow
of blood.
 Blood is at low pressure,
 Transport
but nearby muscles
low pressure
VEIN
squeeze veins and help
blood to the
push blood to the heart
heart
 Large diameter and thin
walls reduce resistance
to flow of blood
 One cell thick walls for
easy diffusion
 Allow
 Highly branched; large
substances to
CAPILLARY
surface area
diffuse into
 Capillary beds constantly
cells
supplied with fresh
blood, so diffusion occurs
 Useful substances move out of plasma of capillaries into
tissue fluid (fluid in between cells in tissues)
 Cells need oxygen and nutrients, and produce waste
products such as CO2 & useful products such as hormone
 Capillaries are constantly supplied with new blood,
otherwise diffusion could not occur
 Lungs → heart
 Heart → Lungs
= Pulmonary vein
= Pulmonary artery
 Liver → heart
 Heart → Liver
= Hepatic vein
= Hepatic artery
 Kidneys → heart
 Heart → Kidneys
= Renal vein
= Renal artery
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FUNCTION
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9.7 Lymphatic System
 Circulation of body fluids, and the production of
lymphocytes.
 Lymph node contains many lymphocytes which filter
lymph.
 Tissue fluid: made when plasma is squeezed out of
capillaries.
 Substances diffuse between cells and tissue fluid.
 Lymph vessels collect lymph and return it to the blood.
 Tissue fluid returns to the capillaries by osmosis.
9.8 Blood
 Red blood cells: haemoglobin and oxygen transport
 White blood cells: phagocytosis and antibody formation
 Platelets: causing clotting
 Plasma: transport of blood cells, ions, soluble nutrients,
hormones, carbon dioxide, urea and plasma proteins
9.9 Immune system
PHAGOCYTE
 Phagocyte has lobed
nucleus and vesicles
containing digestive
enzymes.
 Phagocytosis: engulf
pathogen, vesicles fuse
with vacuole, enzymes
digest bacteria.
 Antigen: protein/
carbohydrate on surface
of pathogen which
provokes immune system
LYMPHOCYTE
 Lymphocytes are found
in blood and in lymph
nodes
 Large nucleus and they
produce antibodies,
 Antibodies: Y-shaped
protein, bind to label
pathogens.
 Then either destroyed
by being ingested by
phagocytes, or the
antibodies may do it.
9.10 Blood Clotting
 Reduces blood loss and keeps pathogens out
 Fibrinogen (inactive) turns to fibrin (activated), and
forms a mesh to trap red blood cells, which eventually
dries to form a scab.
10. DISEASES AND IMMUNITY
10.1 Pathogens
 Pathogen: a disease-causing organism.
 Transmissible disease: a disease in which the pathogen
can be passed from one host to another.
 The pathogen for a transmissible disease may be
transmitted either:
o Direct contact e.g. through blood, body fluids
o Indirectly e.g. from contaminated surfaces/food, from
animals, from air
10.2 Body Defences
 The human body has many natural defences against
pathogens.
 Mechanical barriers:
o Nostrils contain hairs that help trap dust
o Skin has a thick outer layer of dead cells
 Chemical barriers:
o Sticky mucus which can trap pathogens
o In the stomach, hydrochloric acid is secreted which kills
many of the bacteria in food
 Cells: Pathogens that manage to get through all these
defences are usually destroyed by white blood cells:
o Some of these cells take in and digest the pathogens by
phagocytosis
o Others produce antibodies that incapacitate or kill the
pathogen
o Vaccination against disease helps antibodies to
produce very quickly
10.3 The Immune System
 An antibody is a protein molecule which fits into another
molecule
 Pathogen molecules are called antigens.
 To destroy a pathogen, antibody molecules must be
made which are exactly the right shape to fit into
molecules (antigens) on the outside of the pathogen.
 Antibodies lock onto antigens leading to destruction of
pathogen / marking of pathogens for destruction by
phagocytes
 If a pathogen enters the body, it meets a large number
of lymphocytes. One of these will recognize the
pathogen and divide rapidly by mitosis
 These lymphocytes then secrete antibody, destroying
the pathogens
 Active immunity: defence against a pathogen by
antibody production in the body.
 Active immunity is gained after an infection by a
pathogen or by vaccination.
 Vaccines immunise children against diseases caused by
pathogens
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 Process of vaccination:
o Harmless pathogen given which has antigens
o Antigens trigger an immune response by lymphocytes
which produce antibodies
o Memory cells are produced that give long-term
immunity
 In controlling the spread of disease, it is important to
consider hygienic food preparation, good personal
hygiene, waste disposal and sewage treatment
 Passive immunity: short-term defence against a
pathogen by antibodies acquired from another
individual, e.g. mother to infant
 Memory cells are not produced in passive immunity
 Babies get passive immunity by breast feeding.
o Breast milk contains antibodies from the mother which
are passed on to her baby.
o Useful because a young baby’s immune system is not
well developed and so the mother’s antibodies can
protect it against any diseases to which she is immune
for the first few months of its life
 Some diseases are caused by the immune system
targeting and destroying body cells (Type 1 diabetes)
11. GAS EXCHANGE IN HUMANS
11.1 Gas Exchange
PROPERTY OF SURFACE
THIN (ONE CELL THICK)
LARGE SURFACE AREA
MOIST
WELL VENTILATED
CLOSE TO BLOOD
SUPPLY
REASON
Short distance to diffuse
Many molecules can diffuse
at once
Cells die if not kept moist
Concentration gradients for
oxygen and carbon dioxide
are kept up by regular fresh
supplies of air
Gases can be carried
to/from the cells that
need/produce them
11.2 Structure
 Cartilage (in trachea): prevents the trachea from
collapsing during absence of air and also to protect it
 Ribs: to protect vital organs and blood vessels and
expands and contracts (and efficient breathing)
 Intercostal (internal & external) muscles: situated
between the ribs that create and move the chest wall
 Diaphragm: produces volume and pressure changes in
the thorax leading to the ventilation of the lungs
INSPIRED AIR
 21% oxygen
 0.04% carbon dioxide
 78% nitrogen
 Water vapour varies to
climate
EXPIRED AIR
 18% oxygen
 3% carbon dioxide
 78% nitrogen
 Saturated water vapour.
 Test for CO2: Blow CO2 through limewater. +ve result =
turn cloudy
11.3 Effect of Physical Activity on Breathing
 Physical activity increases the breathing rate – more
breaths per minute, and the tidal volume – more air per
breath
 This is measured with a spirometer to produce a
spirogram.
 During exercise, tissues respire at a higher rate, the
change in breathing volume and rate helps to keep CO2
concentration and pH at safe levels.
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11.4 Breathing
BREATHING IN
 External intercostal
muscles contract – pulls
rib cage upwards and
outwards
 Diaphragm muscles
contract – diaphragm
moves upwards
 Lung volume increases –
and pressure falls
 Air rushes in to equalise
pressure
12.2 Anaerobic Respiration
BREATHING OUT
 External intercostal
muscles relax – rib cage
falls downwards and
inwards
 Diaphragm muscles relax
– returns to dome shape
 Lung volume decreases –
and pressure increases
 Air is forced out
 Release of a relatively small amount of energy by the
breakdown of food substances in the absence of oxygen.
 In muscles:
Glucose → lactic acid
C6H12O6 → 2 C3H6O3
 In yeast (single-cell fungi):
Glucose → ethanol + carbon dioxide
C6H12O6 → 2C2H5OH + CO2
 Disadvantages of anaerobic respiration:
o Only produces 1/20 of the energy per glucose
molecule that aerobic respiration would
o Produces poisonous lactic acid
 Lactic acid:
o Transported in blood to heart, liver and kidneys,
which oxidize it
o The heart, liver and kidneys need extra oxygen to do
this which causes you to continue breathing heavily
after exercise.
o The extra oxygen is called the oxygen debt.
13. EXCRETION IN HUMANS
 Internal intercostal muscles: are used in coughing and
sneezing.
 Mucus & cilia: goblet cells produce sticky mucus to trap
and eliminate particulate matter and microorganisms.
 Ciliated cells have cilia: little hairs which sweep back and
forward in a coordinated way to brush mucus up the
lungs into the mouth
12. RESPIRATION
 Chemical reactions that break down nutrient molecules
in living cells to release energy.
 Uses of energy in the body of humans: muscle
contraction, protein synthesis, cell division, active
transport, growth, the passage of nerve impulses and
the maintenance of a constant body temperature.
 Respiration involves the action of enzymes in cells
 Excretion: the removal from organisms of toxic
materials, the waste products of metabolism (chemical
reactions in cells including respiration) and substances in
excess of requirements.
 Substances should include carbon dioxide, urea and
salts.
13.1 Function of Kidney
 Removal of urea and excess water and the re-absorption
of glucose and some salts
 Urea is formed in the liver from excess amino acids
 Alcohol, drugs & hormones are broken down in the liver
12.1 Aerobic Respiration
 Release of a relatively large amount of energy in cells by
the breakdown of food substances in the presence of
oxygen.
Glucose + oxygen → carbon dioxide + water
C6H12O6 + 6O2 → 6CO2 + 6H2O
 Cortex: contains Bowman’s capsules and coiled tubules
 Ureter: carries urine from kidney to bladder
 Medulla: contains loops of Henlé and collecting ducts
 Loop of Henlé: selectively absorbs water/solutes
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 Collecting ducts: reabsorbs water into blood and store
wastes until they are passed into ureter
 Urethra: carried urine from bladder to the outside.
 Bladder: stores urine
 Renal capsule: filters from blood: water, glucose, urea
and salts.
 Tubule: (yellow) reabsorbs 100% of glucose, most of the
water and some salts back into the blood (red), leading
to concentration of urea in the urine as well as loss of
excess water and salts into the tubule.
 Renal artery: brings wastes and water from blood
 Renal vein: reabsorbs water and useful molecules and
leaves wastes behind
13.2 Structure of the Kidney
5. Collecting duct: the remaining substances move
through the second coiled tubule (distal tubule), into
the collecting duct. The permeability of this part of the
nephron to water is controlled
13.3 Dialysis
 When a kidney machine takes a patient’s blood and
cleans it, then returns the blood to circulation.
 This is how it works:
o Blood enters machine from patient
o The pump passes the blood passes the dialysis tubing
which is semi-permeable therefore acting as a filter
o The surrounding liquid contains some salts, glucose
but no urea so waste materials pass from blood by
diffusion;
o The ‘cleaned' blood returns to patient's
circulation/body
DIALYSIS
TRANSPLANT
 More expensive in the
 Less expensive in the
long run
long run
 Very disruptive (three 6-  Not very disruptive (only
8 hrs sessions per week)
have to take
medication)
 Do not need to find
kidney
 Need a kidney
 Need a machine & must  Can go anywhere,
live near one
anytime
 Risk of rejection
14. COORDINATION AND RESPONSE
1. Ultrafiltration: blood from renal artery enters the
glomerulus. Water, urea, salts and glucose are forced
into the Bowman’s capsule. Blood cells and large
proteins cannot pass through.
2. Selective reabsorption: in the proximal tubule two
thirds of the salt and water and all the glucose moves
out of the nephron, by active transport. These
substances are reabsorbed back into the blood
capillary.
3. Loop of Henlé: this part of the loop of Henlé is
permeable to water but not salt. Water passively
diffuses out of the nephron because of the low water
potential of the medulla tissue fluid.
4. Loop of Henlé: this part is permeable to salt but not
water. The loss of water from the filtrate in the
previous stage increases the salt concentration. Some
salt passively diffuses out of the loop here.
14.1 Nervous Control in Humans
 The nervous system consists of two parts:
o Central nervous system (CNS) consisting of the brain
and spinal cord, which are the areas of coordination
o Peripheral nervous system (PNS) made up of nerves
and neurones, which coordinate and regulate bodily
functions.
 Involuntary actions: not under conscious control e.g.
reflex action
 Voluntary actions: are done if we decide to carry them
out
14.2 Types of Neurons
 Nerve impulse: an electrical signal that passes along
nerve cells called neurones
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Motor Neurone:
 Reflex action: means of automatically and rapidly
integrating and coordinating stimuli with the responses
of effectors (muscles and glands)
Sensory Neurone:
14.4 Synapses
Relay (connector) neurone:
14.3 Reflex Arc
 A reflex action is an involuntary, quick action to respond
to a stimulus, in order to protect the body from danger
 E.g. quickly removing your hand from hot metal surface
 They involve three neurones: a sensory neurone, relay
neurone and motor neurone.
 The gap between neurones is called a synapse.
 How the reflex arc works:
o A stimulus affects a receptor (cell or organ that
converts a stimulus into an electrical impulse)
o A sensory neurone carries impulse from the receptor
to the CNS
o Connector/relay neurone carries impulse slowly
(because it has no myelin sheath) across the spinal
chord
o Motor neurone carries impulse from the CNS to the
effector
o Effector (either a muscle or a gland) carries out the
response
 Synapse: a junction between two neurones, consisting of
a gap across which impulses pass by diffusion of a
neurotransmitter
 Synaptic cleft: small gap between each pair of neurones
 Inside the neurones axom, there are 100s of tiny
vacuoles (vessicles each contain a chemical called
neurotransmitter)
 When an impulse arrives, the vessicles move to the cell
membrane and empty their content into the synaptic
cleft
 The neurotransmitter quickly diffuses across the tiny gap
and attaches to receptor molecules in the cell
membrane of the relay neurone
 This can happen because the shape of the
neurotransmitter molecules is complimentary to the
shape of the receptor molecule
 Many drugs e.g. heroin act upon synapses
14.5 Antagonistic Muscle
 A muscle that opposes the action of another; e.g. biceps
and triceps are antagonistic muscles or circular and
radial muscles in the eye
 Agonist: a muscle that contracts while another relaxes;
e.g. when bending the elbow the biceps are the agonist
 Antagonist: a muscle that relaxes while another
contracts; e.g. when bending the elbow the triceps are
the antagonist
 Sense organ: groups of receptor cells responding to
specific stimuli: light, sound, touch, temperature and
chemicals.
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14.6 The Eye
14.8 Pupil Reflex
 The sense organ responsible for sight
 Adjusting for high and low light intensity
LOW LIGHT INTENSITY
 Radial muscles (straight
lines) contract and
become shorter to pull
the pupil (black dot)
making it wider, to let
more light enter, to form
a clear image on retina
HIGH LIGHT INTENSITY
 Circular muscles
(circular lines) contract
and become shorter to
reduce the size of the
pupil to protect retina
from bleaching.
14.9 Rods and Cones
 Cornea: refracts light
 Iris: controls how much light enters pupil
 Lens: focuses light onto retina
 Retina: contains light receptors, some sensitive to light
of different colours
 Optic nerve: carries impulses to the brain
14.7 Accomodation
RODS
 Provide low detail, black
& white images, good for
seeing in low intensity
light (at night).
 Packed most tightly
around edge of retina so
you can see things most
clearly when not looking
directly at them.
CONES
 Provide detailed,
coloured images; they
work in high light
intensity.
 Most tightly packed at
centre of retina, so
objects are seen most
clearly when being
directly looked at.
 Fovea:
o Part of the retina where the receptor cells are pushed
most closley together
o Where light is focused when you look straight at an
object
 Adjusting for near and distant objects.
14.10 Hormones
 A chemical substance, produced by a gland, carried by
the blood, which alters the activity of one or more
specific target organs and is then destroyed by the liver.
14.11 Adrenaline
NEAR OBJECT
 Ciliary muscles contract
 Ligaments relax
 Lens becomes short and
fat
DISTANT OBJECT
 Ciliary muscles relax
 Ligaments are tight
 Lens becomes long and
thin
 A hormone secreted by the adrenal gland.
 It increases pulse rate, makes the glycogen in muscles
get converted to glucose, and released into blood,
makes you breath deeper and more rapidly, airways
become wider, and makes skin become pale as blood is
diverted away.
 Increases conc. of glucose in the blood for respiration.
 Adrenaline is secreted for example: while bungee
jumping or riding a rollercoaster
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GLAND
ANDRENAL
GLAND
HORMONE
Adrenaline
PANCREAS
Insulin
TESTIS
Testosterone
OVARY
Oestrogen
FUNCTION
Prepares body for vigorous
action
Reduces conc. of glucose in
blood
Causes development of
male sexual characteristics
Causes development of
female sexual
characteristics
14.15 Glucoregulation
 Blood glucose levels are monitored and controlled by the
pancreas
 The pancreas produces and releases different hormones
depending on the blood glucose level
 Insulin is released when blood glucose levels are high –
the liver stores excess glucose as glycogen
 Glucagon is released when blood glucose levels are low –
the liver converts stored glycogen into glucose and
releases it into the blood
14.12 Nervous and Hormonal Systems
COMPARISON
SPEED OF
ACTION
NATURE OF
MESSAGE
NERVOUS
SYSTEM
Very rapid
ENDOCRINE
SYSTEM
Can be slow
Electrical
impulses,
travelling along
nerves
Chemical
messenger
(hormones)
travelling in
bloodstream
DURATION OF Usually within
May take years
RESPONSE
seconds
(puberty)
AREA OF
Localized
Widespread
RESPONSE
response (only
response (in
one area usually) many organs)
EXAMPLE OF
Reflexes such as
Development of
PROCESS
blinking
reproductive
CONTROLLED
system
 Hormones are used in food production, for example
oestrogen is used to boost growth rate of chickens.
 Advantage: chickens grow quickly meaning more profit.
 Disadvantages: this may cause human males to develop
feminine characteristics, and it is unnatural.
14.13 Homeostasis
 The maintenance of a constant internal environment.
 Homeostasis is the control of internal conditions within
set limits
14.14 Negative Feedback
 Feedback controls the production of hormones – the
hormones regulate their own production.
 A negative feedback control is when the change in
hormone level acts as a signal to cancel out that change,
so when blood hormone level is low, hormone
production is stimulated, when it is high, it is inhibited.
 When the control of blood glucose does not work, a
person is said to have diabetes
 Type 1 diabetes is caused by the death of the cells that
secrete insulin
o Symptom: hyperglycaemia (feel unwell, dry mouth,
blurred vision and feel thirsty) or hypoglycaemia (tired,
show confusion and irrational behaviour)
o Treatment: eating little and often and avoiding large
amount of carbohydrates, injecting insulin to reduce
blood glucose concentration
14.16 Thermoregulation
Constant body temperature is maintained by:
 Insulation: provided by
fatty tissue retains heat.
Hairs become erect to
trap warm air by
contracting erector
muscles and vice versa.
 Vasodilatation: when it is
hot, arterioles, which
supply blood to the skinsurface capillaries, dilate
(become wider) to allow more blood near to skin surface
to increase heat loss (face redder)
 Vasoconstriction: when it is cold, arterioles, which
supply blood to the skin-surface capillaries, constrict
(become smaller) to allow less blood near to skin surface
to decrease heat loss
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 Sweating: the water evaporates giving a cooling effect
 Skin receptors: sense heat and sensory neurons send
impulses to the hypothalamus
 Shivering: muscular activity generates heat
 Thermoregulatory centre: in the hypothalamus, it
controls the use of corrective mechanisms (e.g. sweating
and shivering).
 Phototropism: a response in which a plant grows
towards (positive) or away (negative) from the direction
from which light is coming.
 Auxins’ role in phototropism:
o If sun shines on right side of a plant’s shoot, auxins
will accumulate on dark opposite left side.
o Auxins accumulating makes cells on left side grow
faster than cells on right side.
o When left side of shoot starts growing faster than
right side, shoot will start to bend to right side towards
sunlight.
 Hormones can be used as weed killers: spraying with
high concentrations of hormone (2,4-D) upsets normal
growth patterns. It affects different species differently so
might only kill one species not the other (this is good).
15. DRUGS
14.17 Homeostatic Organs
15.1 Drugs
 Cells: change composition of blood as they remove
nutrients and O2 and add wastes and CO2
 Heart: keeps blood pressure constant to deliver oxygen
and nutrients around body
 Skin: to maintain heat exchange with external
environment
 Kidneys: regulate water and salt levels (osmoregulation)
and the removal of wastes like urea (excretion)
 Lungs: regulate gas exchange
 Intestines: supply soluble nutrients and water to blood
 Liver: regulates blood solutes and removes toxins
 Any substance taken into the body that modifies or
affects chemical reactions in the body.
14.18 Tropic Responses
 Auxin:
o Plant hormones or growth substances
o Controls tropisms
o It is produced by cells at the tip of roots and shoots of
plants
 Gravitropism: a response in which a plant grows towards
(positive) or away (negative) from gravity.
 Auxins’ role in gravitropism:
o Tend to settle at the bottom end of the root.
o However, this does not make the cells of the tip of
the root grow longer; auxins prevent cells at bottom tip
of root from growing, making cells at top of root grow
faster.
o When cells of top of the root grow faster, they push
root deeper into soil and root gets longer.
o The root grows in direction of the gravitational pull.
15.2 Antibiotics
 Antibiotics work by stopping a metabolic practice
performed by the bacteria you are trying to get rid of,
but not performed by human cells.
 Some bacteria are resistant to antibiotics which reduces
the effectiveness of antibiotics
 Development of resistant bacteria such as MRSA can be
minimised by limiting use of antibiotics only when
essential and ensuring treatment is completed
 Antibiotics don’t work on viruses because they are not
really living and they make the host cell perform the
tasks for them.
15.3 Heroin
Effects of the abuse of heroin: a powerful depressant
 Problems of addiction
 Severe withdrawal symptoms (vomiting, restlessness)
 Malnourishment as drug depresses appetite
 Financial problems – stealing, loss of job
 Infection from sharing needles e.g. HIV/AIDS
 Heroin affects the nervous system by its effect on the
function of synapses
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16 REPRODUCTION
15.4 Alcohol
Effects of excessive consumption of alcohol –a depressant:
 Causes coronary heart diseases
 Reduced self-control
 Depression
 Effect on reaction times
 Damage to liver – cirrhosis
15.5 Smoking
Some effects of tobacco smoke:
 Drying effect and heat irritate lungs – destroys cilia
 Nicotine is addictive, it is also a stimulant, it increases
pulse rate and narrows blood vessels which can cause
damage
 Tobacco smoking can cause chronic obstructive
pulmonary disease (COPD), lung cancer and coronary
heart disease
 Tar causes cancer, and is an irritant so causes coughing.
 There are other irritants in tobacco smoke including:
smoke particles, ammonia, and sulphur dioxide
 Emphysema: walls between alveoli break making large
sacs, reducing surface area massively and making you
breathless after a couple of steps
 Loss of limbs due to poor circulation, CHD and lower
sperm-count
 Carbon monoxide irreversibly bonds with haemoglobin
which can lead to oxygen starvation
 Cancer of the stomach, pancreas and bladder etc.
 Liver is the site of breakdown of alcohol and other toxins
15.6 Hormones and Sports
 Hormones: can be used to improve sporting
performance
 Testosterone
o Improved hand- eye coordination
o Improved body-fat composition
o Increased muscle mass
 Anabolic Androgenic Steroids
o Affects limbic system
 Mood swings
 Impaired judgement
 High blood pressure
 Kidney failure
o Increased risks of prostate cancer (male)
o Inconsistencies of menstrual cycle (female)
o Changes in blood cholesterol
16.1 Asexual Reporudction
 The process resulting in the production of genetically
identical offspring from one parent.
 Bacteria:
o Reproduce by binary fission, each bacterium divides
into two.
o The generation time is the time taken for a cell to
divide into 2.
 Fungi:
o Single-celled yeast reproduces by binary fission.
o All other fungi produce via spores.
o When the sporangium bursts it spreads the spores.
o Spores land and grow mycelium (roots) for example
mushrooms
 Potatoes:
o The shoot from a potato goes back underground and
the stem swells to form a new genetically identical
potato.
o The swollen stem acts as a storage organ.
ADVANTAGES
DISADVANTAGES
 Fast: no need to find
 No variation
mate, fertilise etc.
 Harmful genes
 Good characteristics are
transferred
kept
 Overcrowding- fighting
for food
16.2 Sexual Reproduction
 Sexual reproduction: process involving the fusion of the
nuclei of two gametes (sex cells) to form a zygote and
the production of offspring that are genetically different
from each other
 Fertilisation: the fusion of gamete nuclei
 Nuclei of gametes are haploid and that the nucleus of a
zygote is diploid
ADVANTAGES
 Produces genetically
different offspring; don’t
all die from change in
the environment
PAGE 22 OF 35
DISADAVNATGES
 Takes lots of time and
energy
 Good characteristics can
be lost
 Energy on improving
appearances or pollen
volume for pollination
(plants)
CIE IGCSE BIOLOGY//0610
 Anther & stigma inside
flower
 Stick stigma
 Flowers have stripes
which act as guide-lines
for insects
16.3 Sexual Reproduction in Plants
 Insect pollinated, dicotyledonous flowering plant:
foxglove
 Anther & stigma hangs
out
Stigma hairy
 Pollen tube: pollen grain lands on stigma and creates a
tunnel down the style, through the micropyle, to the
ovules.
 Structure of non-endospermic seed:
Wind pollinated flower structure: grass
16.4 Functions
 Sepal: protect the flower bud.
 Petal: brightly coloured and scented and may have
nectarines which are all used to attract insects, petals in
wind pollinated flowers are tiny, and used for pushing
the bracts (leaf-like structures) apart to expose stamens
and stigma
 Anther: has pollen sacs with pollen grains which contain
the male nucleus (male gamete).
 Stigma: platform on which pollen grains land
 Ovary: hollow chamber, ovules grow from the walls.
16.5 Pollination
 Pollination: transfer of pollen grains from the male part
of the plant (anther of stamen) to the female part of the
plant (stigma).
 Agents of pollination: insects, birds, mammals, water
and wind
INSECT POLLINATED
WIND POLLINATED
 Large colourful petals –
 Dull petals
attract
 No scent
 Sweetly scented
 No nectaries
 Nectaries
 Huge amount of pollen
 Moderate amount of
 Pollen round and
pollen
smooth
 Pollen is spiky/sticky
 Formation of a seed: the zygote divides many times by
mitosis to form and embryo. The cotyledon is the food
store. The testa stops drying out of embryo.
 Wind and animal dispersal are used by plants to colonise
new areas; done because new areas have less
competition for light, space and nutrients, so seeds are
more likely to develop.
WIND DISPERSED SEED
 Dandelion
 Sycamore
SELF POLLINATION
 Pollen is transferred
from the anther to the
stigma of the same
flower.
 Implications:
O Very efficient
O No genetic variation
PAGE 23 OF 35
ANIMAL DISPERSED SEED
 Apple (internal)
 Bur (external)
CROSS POLLINATION
 Pollen transfer from
anther to stigma of
another flower of the
same species.
 Implications
o Risky: pollen might
not reach other flower
o Chance for genetic
variation
CIE IGCSE BIOLOGY//0610
16.6 Germination
 A process controlled by enzymes
 Water: activates enzymes to turn insoluble food stores
into soluble substances, and makes tissues swell so that
the testa splits
 Oxygen: enters through the gaps in the testa (along with
water), and is used in aerobic respiration.
 Temperature: must be suitable for enzymes to work (at
optimum temperature).
o Ovary: contains follicles which develop into the ova
and produces progesterone and oestrogen
o Oviduct (fallopian tube): carries the ovum to uterus
o Uterus (womb): where the fetus develops.
o Cervix: neck of uterus: a strong rigid muscle, moist by
mucus with a small opening
o Vagina: receives penis during intercourse, and way
out for baby at birth. Moist tube of muscle, flexible and
secretes mucus
16.8 Menstrual Cycle
16.7 Sexual Reproduction In Humans
 Male reproductive system:
o Testes: have many coiled tubes which produce sperm,
and the cells between tubes produce testosterone.
o Scrotum: holds testicles
o Sperm duct: carries sperm from testicles to urethra.
o Prostate gland: makes seminal fluid
o Urethra: carries semen from sperm duct to tip of
penis
o Penis: male sex organ, used to transfer semen to the
female.
 Female reproductive system:
 Day 1 to 5:
o In the ovary, FSH secreted by the Pituitary Gland to
stimulate the maturation of ONE follicle in the ovary.
o In the uterus: the endometrium breaks down;
menstruation
 Day 5 to 12:
o In the ovary the follicle keeps maturing
o In the uterus, oestrogen is secreted by follicle and the
ovarian tissues to prepare the endometrium
 Day 13/14/15:
o In the ovary, LH is also secreted by the Pituitary Gland
to trigger the release of the egg from follicle into the
fallopian tube
 Day 15 to 28:
o In the ovary, LH triggers formation of Corpus Luteum
o In the uterus: progesterone is secreted by Corpus
Luteum to keep endometrium thick, waiting for
possible embryo implant.
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 Day 28 – Scenario 1: Egg not fertilized
o No implantation takes place, the Corpus Luteum
degenerates, causing a lack of progesterone.
o This means that endometrium is no longer thick, back
to Day 1
 Day 28 – Scenario 2: Egg is fertilized
o Implantation occurs.
o This makes the hormones to keep the Corpus Luteum
maintained which means that progesterone is high.
o This keeps the Endometrium thick for pregnancy
16.9 Hormones in Menstrual Cycle
 Oestrogen is secreted by the ovaries. It stops FSH being
produced - so that only one egg matures in a cycle and it
stimulates the pituitary gland to release hormone LH.
 Progesterone is a hormone secreted by ovaries. It
maintains the lining of the uterus during the middle part
of the menstrual cycle and during pregnancy.
 Follicle stimulating hormone (FSH) is secreted by the
pituitary gland. It causes an egg to mature in an ovary
and it stimulates ovaries to release hormone oestrogen
 Luteinizing hormone (LH): is also secreted by pituitary
gland and causes mature egg to be released from ovary.
16.10 Sexual Intercourse
 Penis fills with blood and becomes erect
 Vagina walls secrete a lubricant.
 Rubbing of the glans (end of penis) against the vagina
wall sets of a reflex action, causes sperm to be released
from the testes, and is transported by peristalsis along
sperm ducts and urethra, where seminal fluid is added to
make semen.
 The exit of semen from the penis is called ejaculation.
 Sperm then swim through the cervix and oviducts to the
first third of the oviduct (from the ovary) where one
combines with the egg.
16.11 Fertilization
 The fusion of an ovum and a sperm to form a zygote.
 Development of zygote:
o One sperm penetrates
o Ovum membrane alters to form barrier against sperm
o Head of sperm (male nucleus) approaches and then
fuses with the nucleus of the ovum.
o Zygote divides over and over, to make a ball of cells
called an embryo.
o It implants itself in the wall of the nucleus
(implantation) which is followed by conception
 Development of foetus: zygote is changed through
growth (mitosis) and development (organization of cells
into tissues and organs)
 Umbilical cord: contains umbilical artery which carries
deoxygenated blood and waste products from foetus to
placenta and umbilical vein which carries oxygenated
blood and soluble food from placenta to foetus.
(Contains foetus’ blood)
 Placenta: organ for exchange of soluble materials such
as foods, wastes and oxygen between mother and
foetus; physical attachment between uterus and foetus.
(Contains mother’s blood)
 Amniotic sac: membrane which encloses amniotic fluid,
broken at birth.
 Amniotic fluid: protects foetus against mechanical
shock, drying out and temperature fluctuations
16.12 Antenatal Care:
 Change in diet:
o More proteins → growth of foetus
o Slightly more fat → the new cells’ cell membrane
o More vitamin C and D → blood vessel walls and bones
o Iron → haemoglobin
o Calcium → growth of bones and teeth
 Guidance on motherhood
 Checks on foetus and mother including: weight check,
blood tests, urine tests, blood pressure checks,
ultrasound scanning etc.
16.13 Labour and Birth
 Labour: The uterine muscular wall contract and cervix
tries to relax, then contractions get more frequent.
Contractions cause amniotic membrane to break and
release amniotic fluid.
 Expulsion: Powerful Contraction pushes baby out.
 Afterbirth: Placenta is expulsed out. All contraction &
pain gone
GAMETE
SIZE
MOBILITY
NUMBER
SPERM
Smaller
Very
Many more
mobile –
(300,000,000)
use its tail
EGG
Larger
Immobile – Fewer and
moved by
limited
peristalsis
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DISADVANTAGES
ADVANTAGES
BREAST FEEDING
 Has antibodies – no
bacteria
 Nutrients- correct
proportion
 Correct temp.
 No additives
/preservatives
 Builds mother-child
bond
 No cost/preparation
 Causes decline in
uterus size
BOTTLED MILK
 Less painful
 Other people can feed
baby
 May contain
supplement vitamins
and minerals
o Diaphragm: used by woman, prevent sperm entering
uterus, reliable, must stay in place 6 hours after sex,
needs a correct size
o Femidom: closed end, has a ring which gets pushed
through cervix and open end’s ring lies against the
labia
o IUD: plastic-coated copper coil, can be left inside for
months or even years, has a string which is used to
remove it out of the vagina, reliable, it irritates uterus
wall preventing implantation
 Surgical:
o Vasectomy: sperm ducts are cut and tied
o Female sterilization: oviducts are cut and tied
16.16 Artificial Insemination
 May be painful
 Mother must be
present
 Damage beauty
 More likely to develop
illness
 Risk of wrong mixture
 Expensive
16.14 Sex Hormones
 At puberty, the pituitary gland starts to stimulate the
primary sex organs; the testes in males and the ovaries
in females.
 Sex hormones – testosterone in males and oestrogen in
females are released into the bloodstream.
 They only affect the target organs which have receptors
which can recognize them.
 Causes secondary sexual characteristics such as the
growth of pubic hair and maturation of sexual organs.
16.15 Methods of Birth Control
 Natural:
o Abstinence: don’t have sex
o Rhythm method: don’t have sex during the fertile
period, only during the safe period
 Chemical:
o Progesterone-only pill: pill which affects the uterus
and makes implantation difficult
o Spermicide: a chemical applied as a gel, cream or
foam which kills sperm. It is very unreliable on its own
but makes barrier methods of contraception more
effective.
 Mechanical:
o Condom: thin rubber covering over penis, it protects
from impregnation and STDs, used by man
 By donor: man’s sperm has a problem, making
impregnation impossible, so a donor gives his sperm.
 In vitro fertilization: an ovum is fertilized outside a
woman’s body. The fertilized ovum is implanted into the
uterus.
 Fertility drugs: drugs which enhance reproductive
fertility. For women, fertility medication is used to
stimulate follicle development of the ovary. The side
effect is multiple pregnancies. They contain varying
amount of FSH and LH.
16.17 Gonorrhoea
 A bacterial infection caused by penetrative sex through
the mouth, vagina or anus
 Symptoms/signs:
o Pain or burning when passing urine
o Greenish/yellow discharge from the penis or vagina
o Inflammation of the testicles
 Effects:
o In men the urethra becomes infected, in woman it is
the cervix.
o If left untreated, the disease can travel through
reproductive tract causing sterility
 Treatment:
o Can be cured with penicillin however no immunity
16.18 Human Immunodeficiency Virus (HIV)
 Transmission: Intercourse, blood transfusion, organ
transplant or sharing needle with infected person
 Prevention:
o Avoid intercourse with many partners
o Use a condom
o Don’t come in contact with other people’s blood
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 How it affects the immune system:
o Infects and destroys lymphocytes
o Decreases efficiency of immune system
o Body becomes liable to infection by other pathogens
17. INHERITANCE
 The transmission of genetic information from generation
to generation
17.1 Chromosome
 Chromosome: a thread of DNA, made up of a string of
genes
 Gene: a length of DNA that is the unit of heredity and
codes for a specific protein. A gene may be copied and
passed on to the next generation
 Allele: any of two or more alternative forms of a gene
 Haploid nucleus: a nucleus containing a single set of
unpaired chromosomes (e.g. sperm and egg)
 Diploid nucleus: a nucleus containing two sets of
chromosomes (e.g. in body cells)
 Inheritance of gender in humans: woman’s gamete can
only carry an “X” chromosome, and a male gamete can
carry either an “X” or “Y” chromosome; females are “XX”
while males are “XY”. There is always a 50% chance of
getting a boy and vice versa.
17.2 DNA & Protein Synthesis
 DNA: control cell functions by controlling production of
proteins, antibodies and receptors for neurotransmitters
 DNA has 2 long strands and 4 nucleotides, AT and CG
 How proteins are made:
o Made from long chains of amino acids (20)
o DNA bases are read as triplets
o DNA is found in the nucleus
o Protein synthesis happens on ribosome in cytoplasm
o mRNA carries information from DNA to ribosome
o When a protein is made, mRNA is made in the
nucleus, copying the base sequence
o mRNA moves out of the nucleus into the cytoplasm
and attaches to the ribosome
o ribosome assembles amino acids into protein
molecules
o the specific order of amino acids is determined by the
sequence of bases in the mRNA
 All body cells in an organism contain the same genes, but
many genes in a particular cell are not expressed
because the cell only makes the specific proteins it needs
17.3 Mitosis
 The nuclear division giving rise to genetically identical
cells in which the chromosome number is maintained by
the exact duplication of chromosomes.
 Mitosis is needed for:
o Growth: in animals each tissue provides its own new
cells when they are needed.
o Repair of damaged tissues: for example when you cut
your skin, mitosis provides new cells to cover up cut.
o Replacement of worn out cells
o Asexual reproduction: in plants
 Stem cells: unspecialized cells that divide by mitosis to
produce daughter cells that can become specialized for
specific functions
17.4 Meiosis
 Reduction division in which the chromosome number is
halved from diploid to haploid
 Gametes are the result of meiosis
 Meiosis results in genetic variation so the cells produced
are not all genetically identical.
17.5 Monohybrid Inheritance
 Genotype: genetic makeup of an organism in terms of
the alleles present (e.g. Tt or GG)
 Phenotype: physical or other features of an organism
due to both its genotype and its environment (e.g. tall
plant or green seed)
genotype + environment + random variation → phenotype
 Homozygous: having two identical alleles of a particular
gene (e.g. TT or gg). Two identical homozygous
individuals that breed together will be pure-breeding
 Heterozygous: having two different alleles of a particular
gene (e.g. Tt or Gg), not pure-breeding
 Dominant: an allele that is expressed if it is present (e.g.
T or G)
 Recessive: an allele that is only expressed when there is
no dominant allele of the gene present (e.g. t or g)
 Pedigree diagrams:
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Genetic diagrams:
1:1 Monohybrid Crosses
3:1 Monohybrid Crosses
 Discontinuous variation is caused by genes alone and
results in a limited number of distinct phenotypes (e.g.
you are either blood group O, A, B or AB, nothing else)
 Mutation: genetic change
 Gene mutation: a change in the base sequence of DNA
 Mutation is the way in which new alleles are formed
 Ionising radiation and some chemicals increase the rate
of mutation
 Mutation is a source of variation e.g. in Down’s
syndrome, where a parent’s chromosomes are unevenly
distributed in meiosis. In fertilisation, a zygote with a
number of chromosomes that is not 46 is created (e.g.
23 + 24). Characteristics: broad forehead, short neck,
downward-sloping eyes, short nose and mental
retardation.
18.2 Sickle Cell Anaemia
 Co-dominance: when neither of two alleles is dominant
to each other.
 There are three alleles for blood group given by the
symbols IA, IB and IO.
 IA and IB are co-dominant giving blood group AB or IAIB,
and both dominant to IO.
 Sex-linked characteristic: a characteristic in which the
gene responsible is located on a sex chromosome and
that this makes it more common in one sex than in the
other
o Colour blindness as an example of sex linkage
 Disease in which the red blood cell has a sickle shape
instead of a round biconcave shape, controlled by a
recessive allele, which causes weakness, aching joints
and poor circulation.
 The fact that it is recessive means that a heterozygous
person can be a carrier: they have the allele but it is not
expressed.
 Being a carrier of sickle cell anaemia makes you resistant
to malaria
 In equatorial Africa, being sickle cell anaemic causes
death, malaria causes death, but the carriers have
immunity to malaria and have some symptoms of
anaemia, in severe cases they are very weak.
18.3 Adaptive Features
 Adaptive feature:
o inherited feature that helps an organism to survive and
reproduce in its environment
o the inherited functional features of an organism that
increase its fitness
18. VARIATION & SELECTION
 Fitness: the probability of an organism surviving and
reproducing in the environment in which it is found
18.1 Variation

Xerophytes: live in deserts where water is scarce and
 Variation: differences between individuals of the same
evaporation is rapid, or in windy habitats. Their features
species
 Phenotypic variation is caused by both genetic and
are:
environmental factors
o Deep roots to reach water far underground
 Continuous variation is influenced by genes and
o Leaves reduced spines with minimum surface area for
environment, resulting in a range of phenotypes
transpiration
between two extremes, e.g. height in humans
o Shallow spreading roots to collect occasional rain
o Rolled leaves, leaf hairs and stomata sunk in pits to
trap moist air
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o Waxy leaf cuticle, impermeable water
o Stomata opening at night and closed at midday when
evaporation is highest
o E.g. cactus and marram grass
 Hydrophytes: live in wholly or partly submerged in
water. Their features are:
o Leaves are highly divided to create large surface area
for absorption and photosynthesis
o Very little cuticle formation
o Lack of xylem tubes, no stomata underside of leaves
o Stomata is in the upper surface, has a thick waxy layer
to repel water and to keep the stomata open and clear
o Roots are often reduced and root hairs are often
absent
18.4 Natural Selection
 The greater chance of passing on of genes by the best
adapted organisms.
 Variation is natural or random changes in all living
organisms.
 Variation leads to survival of the fittest since the
variations in certain organisms allow that organism to
have an advantage over the others in its species in that
area
 The surviving organisms reproduce, since they don’t get
eaten up, so variation has caused the species to evolve.
 Evolution is caused by natural selection which is caused
by a change in the environment
18.5 Artificial Selection
 Is breeding organisms with valued characteristics
together in order to try to produce offspring which
shares those useful characteristics (selective breeding).
 Can be used to produce organisms which are more
economically valued
 For example: cows that produce more milk, wheat that is
easier to separate from grain, dogs which have better
appearance
 Selective breeding:
o Selecting by humans of individuals with desirable
features
o Crossing three individuals to produce the next
generation
18.6 Resistant Antibiotic
 Strains of antibiotic-resistant bacteria are developing as
the use of antibiotics is increasing.
 In a group of many bacteria, one might mutate to be
resistant to the antibiotic, as a result it reproduces and
the others die making a new strain of bacteria, which is
resistant to antibiotics.
 The susceptible (weak) bacteria are killed first
 Only resistant (strong) bacteria are left
19. ORGANISMS AND THEIR ENVIRONMENT
19.1 Food Chains and Food Webs
 The sun is the principal source of energy input to
biological systems.
 Energy flow is not a cycle; it starts from the sun and then
that energy is harnessed by plants which are eaten by
animals which are eaten by other animals.
 At each step, energy is lost to the environment.
 Food chain: a chart showing the flow of energy (food)
from one organism to the next beginning with a
producer, for example:
Mahogany tree → caterpillar → song bird → hawk
 Food web: showing the transfer of energy from one
organism to the next, beginning with a producer
o Energy is transferred between organisms in a food
chain by ingestion
 Producer: an organism that makes its own organic
nutrients, usually using energy from sunlight, through
photosynthesis
 Consumer: an organism that gets its energy by feeding
on other organisms
 Herbivore: an animal that gets its energy by eating
plants
 Carnivore: an animal that gets its energy by eating other
animals
 Decomposer: an organism that gets its energy from dead
or waste organic matter (i.e. a saprotroph)
 Ecosystem: a unit containing all of the organisms and
their environment, interacting together, in a given area
e.g. decomposing log or a lake
 Trophic level: position of an organism in a food chain,
food web or pyramid of biomass, numbers or energy
o Primary consumer: eat vegetables
o Secondary consumer: eat meat/drink milk
o Tertiary consumer: eat a predatory fish, salmon
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Food chains usually have fewer than five trophic levels,
because energy transfer is inefficient:
 Sun produces light, less than 1% of the energy falls onto
leaves.
 Producers ‘fix’ only about 5-8% of that energy, because
of: transmission, reflection and incorrect wavelength.
 Primary consumer only gets between 5-10% because
some parts are indigestible (e.g. cellulose) and not eating
the whole plant.
 Secondary consumer gets between 10-20% because
animal matter is more digestible & has higher energy
value
 At each level heat is lost by respiration.
Humans eating plants is more efficient than humans
eating animals because…
 We need only a couple of vegetables to have one meal,
but to have meat we must feed the animal a lot of plant
material in order to get far less meat.
 In the process of raising an animal, plants lose energy to
environment, then animal loses energy to environment
and does not use up all the plant material so it is very
inefficient.
PYRAMID OF NUMBERS
PYRAMID OF BIOMASS
 Shows number of each
organism in a food chain
 When moving up
pyramid, number of
individuals’ decreases
19.2 Carbon Cycle
 Pyramid which shows
the biomass
 (number of individuals ×
their individual mass)
19.3 Nitrogen Cycle
 Nitrogen-fixing bacteria provide usable nitrogen for
plants, these may exist in the root nodules where they
live in symbiosis with the plants (nitrogen fixation), or
this can happen because of lightning, or microorganisms
provide them through decomposition.
 Nitrifying bacteria convert nitrogen-containing
substances into better nitrogen-containing substances
for the plants (nitrification).
 Plants absorb these substances and convert them into
proteins
 Primary consumers eat the plants and can make their
own proteins, secondary consumers eat primary
consumers and so on.
 Death and decay happens at each trophic level leading
to stage one
 Denitrifying bacteria carry out denitrification: they
convert nitrogen-containing substances into atmospheric
nitrogen
19.4 Water Cycle
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DEFORESTATION
COMBUSTION OF
FOSSIL FUELS
O2 CONC. IN CO2 CONC.
AIR
IN AIR
Decreases
Decreases
WHY?
Increases
 Burning uses up
oxygen, and produces
carbon dioxide
Increases
 Fewer trees means
less photosynthesis
 Trees are usually
burnt (combustion)
 Decomposition of
tree trunks
(respiration)
19.5 Population
 Population: a group of organisms of one species, living in
the same area at the same time
 Community: all of the populations of different species in
an ecosystem
 Ecosystem: a unit containing the community of
organisms and their environment, interacting together,
e.g. a decomposing log, or a lake
19.6 Factors Affecting Rate of Population
Growth
 Food supply: quantity and quality, for example snails
need calcium to reproduce to make a shell (food quality).
 Predation: if predator population falls, the prey
population will rise
 Disease: causes organisms to die so a high death rate
partly cancels out birth rate meaning less population
growth, especially if the organism dies before giving
birth, or even population decline
 Log phase: exponential growth occurs, the conditions
are ideal and maximum growth rate is reached. Limiting
factors do not limit growth much.
 Stationary phase: limiting factors slow growth as
population has reached “carrying capacity” of its
environment; mortality rate = birth rate; curve levels off
and fluctuates around this maximum population size.
19.8 Human Population Growth
FACTORS FAVOURING
GROWTH:
Lower infant mortality,
higher life expectancy,
better nutrition, better
housing, better sanitation,
medicine, vaccination
FACTORS CONTROLLING
GROWTH:
Disease, famine, war
 The human population is becoming stable (stagnation)
due to:
o better education (particularly for women), so they
work instead of getting married and having children
o better living conditions, fewer people die, fewer
births needed
o cities, reduced need for physical labour on farms
o family planning
 but overall the population in still increasing.
 Social implications of human growth:
o demands for roads as there is an increases number of
cars
o greater expectation for a variety of foods all year
round
o smaller families increase demand for housing
o greater demand for leisure and recreation space
20. BIOTECHNOLOGY & GENETIC ENGINEERING
 Bacteria are useful in biotechnology and genetic
engineering due to their rapid reproduction rate and
their ability to make complex molecules
 Why are microorganisms used:
o Bacteria and fungi are small and easy to grow in a lab
o They reproduce quickly and don’t take up much space
o No ethical issues involved
o Genetic code is the same for bacteria as it is for human
o Bacteria have loops of DNA called plasmids which are
easy to transfer from one cell to another
19.7 Sigmoid Curve
 Lag phase: number of mature, reproducing individuals is
low and they may be widely dispersed
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20.1 Making Biofuel
 Use plants to make sugars which yeast then breaks
down to make ethanol
 Ethanol can then be used as a fuel
o Maize is treated with amylase enzyme (starch to
glucose)
o Add yeast (glucose used in respiration) and make it
respire anaerobically
o Ethanol that is produced is extracted by distillation
o Mixed with gasoline to increase energy and can be
used in cars
20.2 Bread Making
 Flour, sugar, water and salt are mixed with yeast to
make the dough.
 Amylase breaks down some starch to make maltose and
glucose. This is used by yeast in respiration
 The dough is kept in a warm, moist environment (28°c).
Yeast ferments sugar making carbon dioxide which
creates bubbles, so bread rises
 Cooking (at 180°c) – kills yeast, evaporates alcohol and
hardens outer surface.
20.3 Uses of Enzymes
Pectinase:
 Fruit juices are extracted using pectinase (breaks down
pectin)
 Pectin helps plant walls stick together
 If pectin is broke down, it’s easier to squeeze juice from
the fruit
 Extraction of juice from fruit, making juice clear not
cloudy
Washing powders:
 Biological washing powders and liquids contain enzyme
that help remove stain
 The enzymes are coated with a special wax that melts in
the wash releasing the enzyme
 Once the stains have been broken down, they are easier
for detergents to remove
 Proteases break down proteins in stains e.g. grass, blood
 Lipases break down stains containing fats and oil
 Carbohydrases break down carbohydrate-based stains,
such as starch
Lactase:
 Enzyme that breaks down lactose (sugar found in milk)
 People can stop making lactase naturally, therefore can’t
digest lactose
 Milk can be treated with lactase to break down lactose
before a person drinks it
 Also produces glucose & galactose, used in sweets
20.4 Making Penicillin
 Penicillin: an antibiotic produced by a fungus called
penicillium.
 Stainless steel fermentation vessel is filled with medium
containing sugars and ammonium salts.
 Penicillium is added to produce penicillin. They use sugar
for respiration and ammonium salts to make protein and
nucleic acids
 The fermentation vessel
consists of PAWS
o Probes monitor
temperature and pH
o Air provides oxygen
for aerobic
respiration in fungus
o Water-cooled jacket
removes heat to
maintain temperature
of 24C.
o Stirrer keeps the
microorganism
suspended (allowing
access to nutrients and oxygen) while maintaining an
even temperature.
 Filtered to remove fungus and then can be crystallized to
make capsules.
20.5 Genetic Engineering
 Genetic engineering: changing the genetic material of an
organism by removing, changing or inserting individual
genes
 Examples of genetic engineering:
o the insertion of human genes into bacteria to produce
human insulin
o the insertion of genes into crop plants to confer
resistance to herbicides
o the insertion of genes into crop plants to confer
resistance to insect pests
o the insertion of genes into crop plants to provide
additional vitamins
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Human Insulin in Bacteria
 Isolation of the DNA making up a human gene using
restriction enzymes, forming sticky ends
 Cutting of bacterial plasmid DNA with the same
restriction enzymes, forming complementary sticky ends
 Insertion of human DNA into bacterial plasmid DNA
using DNA ligase to form a recombinant plasmid –
insertion of plasmid into bacteria
 Replication of bacteria containing recombinant plasmids
which make human protein as they express the gene
20.6 Genetically Modified Crops
ADVANTAGES
 Uniform in shape – easy
to transport/ appeal
consumers
 Growing season shorter
 Drought resistant – less
water
 Higher yields
DISADVANTAGES
 Natural species may die
 Tastse often not as good
 Lead to development of
super weeds – stronger
than GM
 No one knows long term
effect on humans
21. HUMAN INFLUENCES ON ECOSYSTEMS
21.1 Food Supply
Food production has increased because:
 Improved machinery means less labor is needed
 Fertilizers help crops to grow better
 Insecticides: a type of pesticide that kills insects
 Herbicides: a type of pesticide that kills weeds
 Artificial selection and genetic modification means that
yields are improved: cows produce more milk, cows are
more muscular giving more meat, plant crops can resist
insects and cold weather
World Food Supplies
 Not enough food available in a country to feed its people
because:
o Fast increase in population
o Increasing use of crops for fuel
o Decrease of farming = Climate change/Urbanization
 Famine: Wide spread scarcity of food
 The main causes of famine:
o The rapid rate of population increase
o Long term climatic change
o Soil erosion and desertification
o Economic pressure
o Unequal distribution of food
o Drought
o Flood
 Monoculture is the continuous production of one type
of crop that is often genetically uniform.
 Negative Impacts of Monoculture
o If a natural disaster were to occur, the whole crop
could be wiped out.
o If pests & disease attacked crop, it could harm it easily
o Using large fields and pesticides reduces the variety of
species. This hinders biodiversity.
 Negative Impacts of Intensive Livestock Production
o Welfare issues for the livestock
o Diseases can spread easily among them
o Waste can pollute land and waterways nearby
21.2 Habitat Destruction
 Reason for habitat destruction
o Increased area for food crop growth, livestock
production and housing
o Extraction of natural resources
o Marine pollution
 Through altering food webs, and food chains, humans
can have a negative impact on habitats
 Effects of deforestation
o Reduced biodiversity/destroys habitats/extinction
o Loss of CO2 fixation, thus increase in CO2, thus global
warming
o Soil erosion: tree roots cannot retain soil, goes into
rivers making the water dirty & causes blockages, soil
becomes less fertile
o Flooding: usually 75% of water is absorbed by foliage,
root systems or evaporates. After deforestation water,
accumulates in valleys
21.3 Pollution
Water and air pollution:
 Chemical waste and sewage in rivers results in water not
being drinkable and eutrophication can occur
 Sulphur dioxide dissolves in rain, causing acid rain which
increases acidity of lakes and leaches aluminium out of
the soil causing:
o The fishes’ gills are damaged, eventually killing them.
This is fixed by adding calcium hydroxide (slaked lime)
o Destroys top of trees and aluminium damages tree
roots = dead tree, important nutrients leached away
o SO2 poses health hazards for humans (asthma
sufferers)
o Damages limestone buildings and sculptures
o Fewer crops can be grown on an acidic field (fixed by
adding lime)
PAGE 33 OF 35
CIE IGCSE BIOLOGY//0610
Pollution due to pesticides:
 Insecticides (kill insects): meant to kill insects which eat
crops, but can kill other, useful insects such as bees
which are pollinators, or by bioaccumulation (the
increase in dose of toxin from one level of the food chain
to the next)
 Herbicides (kill weeds): can be harmful to animals which
eat the plants
Nuclear fall-out:
 Radioactive particles are sprayed into the atmosphere in
a nuclear accident or bombing;
 These particle “rain” back to earth from clouds,
sometimes far from the accident site;
 The radioactivity damages DNA and causes cancer and
radiation illness at every level of the food chain.
Non-biodegradable plastics:
 Choke birds, fish and other animals
 Fill up the animals’ stomachs so that they can’t eat food
 Collect in rivers, and get in the way of fish
Acid rain:
 Caused by sulphur dioxide (burning fossil fuels) and
nitrogen oxides (nitrogen reacting hot engines), as they
dissolve and cause acid rain
 Damages trees and plants, and kills fish and other river
life
 Prevention: catalytic converters, in factories slaked lime
neutralizes these acidic oxides and use of flue-gas
desulfurization
Global Warming:
 Increase in average temperature of the Earth
 Started at the same time as humans began burning fossil
fuels
 Scientists believe fossil fuels are causing this – not
proven yet
 Increase in carbon dioxide and methane concentrations
in the atmosphere cause an enhanced greenhouse effect
the leads to climate change
 Negative impact of female contraceptive hormones in
water courses:
 Reduced sperm count in men and feminisation of
aquatic organisms
Eutrophication: when water plants receive too many
nutrients.
 Fertilisers put in soil by farmers
 Fertilisers with nitrates / detergents with phosphates
leach into rivers and lakes after rain
 Water plants grow more than usual
 They block sunlight and kill plants underneath
 They die and sink to bottom
 Bacteria/fungi decompose remains using the O2 and
decreasing the O2 concentration
 Fish and other creatures die from oxygen starvation
21.4 Conservation
 Sustainable resource: one which is produced as rapidly
as it is removed from the environment so that it does
not run out
 Sustainable development: development providing for
the needs of an increasing human population without
harming the environment
 Sustainable development requires:
o Management of conflicting demands
o Planning and co-operation at local, national and
international levels
 Some resources can be maintained, limited to forests
and fish stocks.
 They can be sustained using:
o Education
o Legal quotas
o Re-stocking
Natural resources:
 Water: used to grow food, keep clean, provide power,
control fires and to drink. We get water constantly
through rainfall but we are using up planet’s fresh water
faster than it can be replenished.
 Fossil fuels: need to be conserved as they will soon run
out, they should be therefore replaced with green forms
of energy.
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CIE IGCSE BIOLOGY//0610
Recycling:
 Water: water from sewage can be returned to
environment for human use by sanitation and sewage
treatment
 Paper: sent to special centres where it is pulped to make
raw materials for industry
 Plastic: fossil fuels, bottles → fleece clothing
 Metal: mining takes a lot of energy so recycling saves
energy
Species and habitats: need to be conserved because:
 Organisms have value in themselves (ethical value)
 Value to medicine (new molecules from exotic plants =
new drugs)
 Genetic resources are useful to humans as well and are
lost when species disappear (DNA for genetic
engineering)
 Each species has its role in its ecosystem; if it is removed,
then the whole ecosystem could collapse
Endangered species:
 How they become endangered: climate change, habitat
destruction, hunting, pollution and introduced species
 If the population size drops, variation decreases
 Endangered species can be conserved by: monitoring
and protecting species and habitats, education, captive
breeding programmes and seed banks
 Conservation programmes include:
o reducing extinction
o protecting vulnerable environments
o maintaining ecosystem functions, by nutrient cycling
and resource provision, e.g. food, drugs, fuel and genes
PAGE 35 OF 35
TABLE OF CONTENTS
3
CHAPTER 1
4
CHAPTER 2
5
CHAPTER 3
7
CHAPTER 4
The Particulate Nature of Matter
Experimental Techniques
Atoms, Elements and Compounds
Stoichiometry
8 Electricity and Chemistry
CHAPTER 5
9
CHAPTER 6
10
CHAPTER 7
12
CHAPTER 8
14
CHAPTER 9
15
Chemical Energetics
Chemical Reactions
Acids, Bases and Salts
The Periodic Table
CHAPTER 10
Metals
16
CHAPTER 11
18
CHAPTER 12
18
CHAPTER 13
19
CHAPTER 14
Air and Water
Sulfur
Carbonates
Organic Chemistry
CIE IGCSE CHEMISTRY//9093
1. THE PARTICULATE NATURE OF MATTER
1.1 Kinetic Particle Theory
HeatINCREASES
increases
HEAT
 When a solid is heated, particles vibrate faster about a
fixed point causing particles to move further apart and
so solid expands
 When particles gain sufficient energy to overcome
strong forces of attraction, they move out of their fixed
position and can slide over each other in a continuous
random motion – solid has melted.
 Particles in liquid have energy to move around but are
still close to each other and do not have enough energy
to overcome the forces that hold them close to each
other.
 If more heat’s supplied, particles move faster until they
have enough energy to overcome the forces of
attraction. Particles escape the liquids surface and move
around in continuous rapid motion – the liquid has
boiled
 In the vapor, the particles move in rapid random motion.
This movement is due to collision of vapor particles with
air particles.
1.2 States of Matter
SOLID
 Strong forces
of attraction
between
particles
 Fixed pattern
(lattice)
 Atoms vibrate
but can’t
change
position ∴
fixed volume
and shape
LIQUID
 Weaker
attractive
forces than
solids
 No fixed
pattern, liquids
take up the
shape of their
container
 Particles slide
past each
other.
GAS
 Almost no
intermolecular
forces
 Particles far
apart, and
move quickly
 Collide with
each other and
bounce in all
directions
PROCESS
Melting
Boiling
Condensing
Freezing
Sublimation
Reverse
sublimation
HEAT ENERGY
Gained
Gained
Lost
Lost
Gained
EXO/ENDOTHERMIC
Endothermic
Endothermic
Exothermic
Exothermic
Endothermic
Lost
Exothermic
1.3 Heating Curve
1.4 Diffusion
 Diffusion is the spreading of one substance through
another from a region of high concentration to a region
of low concentration due to the continuous random
motion of particles.
 Evidence for diffusion:
 In liquids: potassium manganate
(VII) in a beaker of water
 In gases: a gas jar of air and a gas
jar of bromine connected
 Factors that affect the rate of diffusion:
 Temperature increases → rate of diffusion increases
 Lower density gas → rate of diffusion is higher
PAGE 3 OF 22
CIE IGCSE CHEMISTRY//9093
 Interpreting simple chromatograms:
o Number of rings/dots = number of substances
o If two dots travel the same distance up the paper
they are the same substance.
o You can calculate the Rf value to identify a substance,
given by the formula:
2. EXPERIMENTAL TECHNIQUES
2.1 Measurement
VARIABLE
 Time
APPARATUS
 Stopwatch or Clock
 Thermomemeter (liquid in glass,
 Temperature
thermistor or thermocouple)
 Mass
 Balance
   
   
 To make colourless substances visible, use a locating
agent:
o Dry paper in oven
o Spray it with locating agent
o Heat it for 10 minutes in oven
 Assesing purity from m.p./b.p:
o Pure substances have a definite, sharp m.p./b.p.
o Substance+impurity has lower m.p. and higher b.p.
o More impurity means bigger change
  =
Measuring Volume:
2.3 Filtration
Beaker
Burette
Pippette
Measuring
Cylinder
Gas
Syringe
 Mixture goes in a funnel with filter paper, into a flask.
 Residue is insoluble and stays at top.
 Filtrate goes through
2.2 Critertia of Purity
 Paper chromatography:
o Drop substance to center of filter paper and allow it
to dry
o Drop water on substance, one drop at a time
o Paper + rings = chromatogram.
o Principle: Difference in solubility separates different
pigments
o Substances travel across paper at different rates
which is why they separate into rings
o Method works because different substances travel at
different levels of attraction to it
2.4 Crystallization
 Stationary phase is material on which separation takes
place
 Mobile phase consists of the mixture you want to
separate, dissolved in a solvent.
 Some water in the solution is
evaporated so solution becomes
more concentrated.
 A drop is placed on a slide to
check if crystals are forming.
 Solution is left to cool and
crystallise.
 Crystals are filtered to remove
solvent.
PAGE 4 OF 22
CIE IGCSE CHEMISTRY//9093
2.5 Simple Distillation
 Impure liquid is heated
 It boils, and steam rises into the condenser
 Impurities are left behind
Condenser is cold so steam condenses to the pure liquid
and it drops into the beaker
If one solid is magnetic, can use a magnet e.g. sand and
iron fillings
SOLVENT
IT DISSOLVES…
Water
Some salts, sugar
White spirit
Gloss paint
Propanone
Grease, nail polish
Ethanol
Glues, printing inks, scented substances
2.8 Choosing a Suitable Method
METHOD OF SEPARATION
Filtration
Evaporation
Crystallization
Simple Distillation
Fractional Distillation
Chromatography
2.6 Fractional Distillation
 Removes a liquid from a mixture of liquids, because
liquids have different b.p.s
 Mixture is heated to evaporate substance with lowest
b.p.
 some of the other liquid(s) will evaporate too.
 A mixture of gases condense on the beads in the
fractional column.
 So the beads are heated to the boiling point of the
lowest substance, so that substance being removed
cannot condense on the beads.
 The other substances continue to condense and will drip
back into the flask.
The beaker can be changed after every fraction
2.7 Seperating Mixture of Two Solids
 Can be done by dissolving one in an appropriate solvent
 Then filter one and extract other from solution by
evaporation
USED TO SEPARATE
A solid from a liquid
A solid from a solution
A solid from a solution
A solvent from a solution
Liquids from each other
Different substances from a
solution
3. ATOMS, ELEMENTS AND COMPOUNDS
3.1 Atomic Structure and the Periodic Table
PARTICLE RELATIVE CHARGE
MASS
(ATOMIC MASS )
1
1
1⁄1837
Proton
+1
Neutron
0
Electron
-1
 Proton number: number of protons in an atom (and
number of electrons in an atom)
 Nucleon number: number of protons + neutrons in an
atom.
 In the periodic table
o The proton number increases by 1 when you go to
the right
o When you go one element down, you increase proton
number by 8 in the first 3 periods (transition elements
not included)
 Isotopes: atoms of same element with different no. of
neutrons
o E.g. Carbon 12 and Carbon 14.
o Two types: non-radioactive isotopes and radioactiveisotopes which are unstable atoms that break down
giving radiations
o Medical use: cancer treatment (radiotherapy) – rays
kill cancer cells using cobalt-60
o Industrial use: to check for leaks – radioisotopes
(tracers) added to oil/gas. At leaks radiation is
detected using a Geiger counter.
PAGE 5 OF 22
CIE IGCSE CHEMISTRY//9093
 Electrons are arranged in electron shells.
 Atoms want to have full outer shells (full set of valency
electrons), this is why they react.
 Noble gases have full outer shells so they have no need
to react.
 Electron shell structure: 2, 8, 8, 18.
 More reactive elements have a greater desire to have a
full outer shell, so also form more stable compounds.
3.2 Bonding: the Structure of Matter
 Element: substance that cannot be split into anything
simpler, in a chemical reaction. Each element has a
unique proton number.
 Mixture: two or more elements mixed together but not
chemically combined
 Compound: substance in which two or more different
elements are chemically combined
METALS
NON-METALS
Strong
Brittle
Poor conductors of heat &
Good conductors of heat
electricity (except
& electricity
graphite)
Lower m.p. and b.p. than
High m.p. and b.p.
metals
High density
Low density
Forms basic oxides
Forms acidic oxides
Forms cations in reactions Forms anions in reactions
Malleable and ductile
Sonorous
Some are magnetic
PROPERTY
Form giant lattice
High m.p. and b.p.
Don’t conduct electricity
when solid
Conduct electricity when
molten/aqueous
Usually soluble in water
REASON
Cations and anions attract
Strong bonds between ions
Ions can’t move
Ions can move
Not required
3.4 Molecules and Covalent Bonds
 When atoms share ̅s to obtain a noble gas electron
structure
 Covalent bonding takes place between non-metals only
SINGLE BOND
DOUBLE BOND
TRIPLE BOND
2̅s shared
(1 from each
atom)
4̅s shared
(2 from each
atom)
6̅s shared
(3 from each
atom)
PROPERTY
Low m.p. and b.p.
Usually liquid, gas or low
m.p solid
Don’t conduct electricity
Usually insoluble in water
 Example:
REASON
Weak intermolecular forces
of attraction between
molecules
No mobile ions/electrons
Not required
 Alloy: Mixture of two or more metals or mixture of one
or more metal with a non-metal, to improve its
properties
3.5 Macromolecules
3.3 Ions and Ionic Bonds
 Chemical bond formed by transfer of ̅s from one atom
to another
 Metals lose ̅s to form cations, non-metals gain ̅s to
form anions
 Positive cations & negative anions attract to each other
 Strong electrostatic force of attraction between positive
cations and negative anions is called ionic bonding
DIAMOND
GRAPHITE
SILICON DIOXIDE
 Four bonds
 Three bonds
 Makes up sand
 High m.p.
 Made of flat
 Each Si is bonded
to 4 oxygen atoms,
 Doesn’t conduct sheets
and each oxygen is
 Used for cutting  Held together by
bonded to 2 silicon
weak forces so is
as is srongest
atoms
known
soft used as a
 it has a high m.p.
substance
lubricant
 Conducts electricity and is hard, like
as it has one free e- diamond
PAGE 6 OF 22
CIE IGCSE CHEMISTRY//9093
 Melting point: high - structure made up of strong
covalent bonds
 Electrical: don’t conduct electricity - have no mobile ions
or electrons, except for graphite
 Strength: hard - exists in tetrahedral structure but
graphite is soft
3.6 Metallic Bonding
4.4 Masses
 Relative atomic mass (Ar): mass of one atom of an
element relative to one twelfth of the mass of one atom
of Carbon-12
 Relative molecular mass (Mr): sum of relative atomic
masses of all the atoms in one molecule of the
compound
4.5 The Mole Concept
 A mole of a substance is the amount that contains the
same number of units as the number of carbon atoms in
12 grams of carbon-12
 A mole is the Ar or Mr expressed in grams e.g. 1 mole of
Carbon-12 is equal to 12 grams.
 It is equal to 6.02 × 1023 atoms, this number is called
Avogadro’s constant.
4.6 Number of Moles
   =
Positive ions held together by electrons – acts like glue
4. STOICHIOMETRY
4.7 Moles in Gases
 Balancing equations: a chemical equation is balanced
when there are equal number of atoms and charges on
both sides of the equation
 State symbols:
o (s) = solid
o (l) = liquid
o (g) = gas
o (aq) = aqueous solution
 = .   × 243
4.8 Concentration
 =
 Moles per dm3
o 1mol/dm3 = 1M
 Grams per dm3, g/dm3
.  

4.9 Molecular Formulae
4.1 Valency Table
NAME
Nitrate
Hydroxide
Acetate/
ethanoate
Carbonate
Sulphate
Silicate
Phosphate

 
FORMULA
NO3OHCH3COO-
VALENCY
1
1
1
CO32SO42SiO32PO43-
2
2
2
3
4.3 Ending of Names
 Compound ending with -ide only contain two different
elements
 Compound ending with -ate contain oxygen
 The formula using the actual number of atoms in a
molecule
4.10 Empirical Formulae
 This is the simplest ratio of the atoms in a compound
 For example:
o Molecular formula of ethanol = C2H5OH
o Empirical formula of ethanol = C2H6O
 To find out the empirical formula you:
o Make the percent ratio into the simplest whole
number ratio (NOTE: if given %s, use them as grams)
o Divide the coefficients of each element symbol by the
lowest coefficient
4.11 Percentages
   ()
   ()
  
× 100
 
   =
   =
PAGE 7 OF 22
× 100
CIE IGCSE CHEMISTRY//9093
5. ELECTRICITY AND CHEMISTRY
5.3 Electroplating
 Decomposition of an electrolyte with the help of electric
current
 Electrolyte:
o Aq. solution of ionic substance or molten ionic salt
o Conducts electricity due to the presence of mobile
ions
 Electrodes:
o Rods which help current enter the electrolyte
o Inert electrodes: do not take part in the reaction
o Reactive electrodes: take part in the reaction
 Coating one metallic object with another metal using
electrolysis
 For electroplating, you need:
o Anode made of metal you
want to electroplate object
with
o Ions of same metal as anode
in solution
o Object to be plated at
cathode
 Used to:
o Make things look better
o Prevent corrosion
5.4 Uses
ALUMINUM
 Used for
 Used in
electricity cables electrical wires
because:
as it is:
o Light
o A very good
o Nonconductor
corrosive
(not best)
o Good
o Ductile
conductor
o Cheaper than
copper
 Cables have
steel core, for
strength
5.1 Principle
At the
cathode
Metal
At the anode
Non-metal
Molten
Electrolyte
At the
cathode
Higher in
reactivity
then H+
H2 formed
Lower in
reactivity
then H+
Metal
formed
Aqueous
Electrolyte
Halide
present
At the
anode
Concentrated
Halogen
fomed
Dilute
Oxygen
formed
Halide not
present
 This is purifying impure metals
 Rules:
o Cathode: thin strip of pure metal
o Anode: impure metal
o Electrolyte: Aqueous Salt Solution of metal
 Example:
Oxygen
Formed
Molten lead(II) bromide
Concentrated hydrochloric acid
Concentrated aqueous sodium
chloride
AT
CATHODE
Lead
Hydrogen
Hydrogen
PLASTIC &
CERAMICS
 Used as
insulators
because they:
o Don’t conduct
electricity
o Conduct heat
poorly
 Plastic used for
casing in plugs
 Ceramics used to
support cables in
electricity pylons
5.6 Refining Metals
5.2 Examples
ELECTROLYTE
COPPER
AT
ANODE
Bromine
Chlorine
Chlorine
PAGE 8 OF 22
CIE IGCSE CHEMISTRY//9093
AT THE ANODE
 Made of titanium
 Chlorine gas evolved
 Unreacted ions (Na+, H+
and OH-) move through
porous membrane due
to difference in liquid
pressure
 Net flow to the right
AT THE CATHODE
 Made of steel
 Hydrogen cations
reduced to H2 molecules
 Left Na+ and OH- which is
aqueous sodium
hydroxide
 Reaction at Anode: Cu – 2e  Cu2+ (mass decreases)
 Reaction at Cathode: Cu2+ + 2e  Cu (mass increases)
6. CHEMICAL ENERGETICS
5.7 Basics
 Exothermic reaction: one that releases heat energy into
the surrounding
 Endothermic reaction: one which absorbs heat energy
from the surroundings
 Bond breaking is endothermic
 Bond making is exothermic
 Electrolysis is a way to decompose compounds, using
electricity.
 Reduction of positive cations happens at the cathode
 Oxidation of negative anions happens at the anode
 For example:
o At the anode: 2Cl- → Cl2 + 2eo At the cathode: 2H+ + 2e- → H2
5.8 Extraction of Aluminium
 The main ore of aluminium is bauxite – high m.p.
 Aluminium (III) oxide (alumina) is dissolved in molten
cryolite (Na3AlF6) – this mixture has a lower m.p.
(industrially preferred)
6.1 Energetics of a Reaction
EXOTHERMIC REACTION
 Energy given out to the
surroundings
 Surroundings become
hot
 Bond making –
exothermic
ENDOTHERMIC REACTION
 Energy is taken in from
the surroundings
 Surroundings become
cold
 Bond breaking –
endothermic
6.2 Energy Level Diagrams
 During electrolysis aluminium is produced at the carbon
cathode and oxygen at the carbon anode.
 Due to the high temp. the oxygen reacts with the
graphite anode to form CO2 and so anode had to be
periodically replaced
5.9 Electrolysis of Brine
 Brine is concentrated NaCl solution
 Ions present: Na+, H+, Cl- and OH-
6.3 Bond Energy
 This is the amount of energy consumed or liberated
when a bond is broken or formed in kJ/mol
∆ =   +  
 If overall heat energy is negative, reaction is exothermic
 If overall heat energy is positive, reaction is endothermic
6.4 Production of Energy
 A fuel is a substance which can be conveniently used as a
source of energy.
 Burning fuels (like oil) to form oxides is an exothermic
reaction.
 The heat from burning fuels is used in power plants to
create steam from water and turn turbines.
PAGE 9 OF 22
CIE IGCSE CHEMISTRY//9093
 In order for any material to combust three things must
be present:
o Fuel
o Heat
o Oxygen
 A good fuel would:
o Be cheap
o Be available in large quantities
o Ba a liquid at room temperature
o Produce a large amount of energy when combusted
o Not produce polluting gases
6.5 Hydrogen
 Burns explosively with oxygen, so it is used in rockets.
 In a fuel cell, it combines with oxygen without burning.
 Produced by reacting methane gas with steam
ADVANTAGES
 Produces a lot of energy
 Abundant on earth (sea)
 Less pollutant
 Renewable fuel
DISADVANTAGES
 Difficult to transport as it
is a gas at room
temperature
 Forms explosive mixture
with air – very dangerous
6.6 Simple Cells
 A cell is a device which converts chemical energy into
electrical energy and is composed of two metals of
different reactivity connected by an external circuit and
an electrolyte
 The process works due to the different reactivity of
metals
 Consists of a negative pole (the more reactive metal) and
a positive pole (less reactive metal) and an electrolyte.
 The greater the difference in reactivity of the two
metals, the greater the voltage will be.
 The electrons flow because one metal is more reactive,
so it has a stronger drive to give up its electrons.
 The atoms give up electrons and enter the solution as
ions.
6.7 Radioactive Isotopes
 Uranium-235 can be used in nuclear power stations to
produce electricity
 The radioactive isotope is bombarded by neutrons
resulting in a lot of heat being produced
 Small amount of radioactive fuel produces large amount
of heat
 Advantages: lots of energy is from a small amount and
no CO2
 Disadvantage: radioactive waste produced and nonrenewable
7. CHEMICAL REACTIONS
7.1 Collision Theorey
 Collisions are needed for a chemical reaction to take
place
 Successful collisions have enough activation energy at
moment of impact to break preexisting bonds and form
new bonds
7.2 Rates of Reaction
 Rate of a chemical reaction is the concentration of
reactant used up or product made in a given time.
 Unit = (mol/dm3)/s
7.3 Concentration
 Increasing concentration of reactants increases rate of
reaction
 This is because there are more particles per unit volume,
so the collision rate between reacting particles increases,
therefore the successful collision rate increases, which
results in an increased rate of reaction.
7.4 Temperature
 Increasing temperature increases the rate of reaction
 This is because average kinetic energy of particles
increase which means they are moving faster & also
more particles have an energy greater/equal to
activation energy, therefore successful collision rate
increases, resulting in increased rate of reaction
PAGE 10 OF 22
CIE IGCSE CHEMISTRY//9093
 For gaseous reactants, if catalyst is solid metal, the
catalyst provides a surface for reaction to take place on
 The larger the surface are of the metal catalyst, the
larger the area for reaction to take place therefore
higher rate of reaction
7.5 Particle Size
 Decreasing the particle size (increasing surface area)
increases the rate of reaction
 This is because there are more reactant particles
exposed to collide, so the collision rate increases,
therefore the successful collision rate increases,
resulting in an increased rate of reaction
 Large surface area can mean danger. For example, flour
dust and wood dust have large surface areas, and are
combustible. A spark from a machine, or a lit match, can
cause an explosion. This also applies to gases from
mines.
 Enzymes are protein molecules. They are biological
catalysts which speed up reactions but remain
chemically unchanged at the end
 Enzymes function best at optimum temperature and pH
level otherwise they may denature and completely stop
functioning
7.8 Measuring Rates of Reaction
Experimentally
GAS EVOLVED
MASS LOSS
COLOUR
CHANGE
If a gas evolves,
measure
volume of gas
produced per
unit time using
a gas syringe
If a gas evolves,
measure loss in
mass per unit
time by placing
on a balance
then putting a
cotton wool on
top to allow gas
to pass but not
to enter
If a color change
occurs we can
measure the time
taken to go
cloudy
7.6 Pressure in Gaseous System
 Increasing the pressure in a
gaseous system increases the
rate of reaction
 The distance between particles
is reduced under pressure
 There are more particles per
unit volume, so the collision
rate increases, therefore the
successful collision rate increases, resulting in an
increased rate of reaction.
7.7 Catalyst
 A catalyst is a substance (usually a transition metal)
which speeds up a chemical reaction, but remains
unchanged at the end
 Adding a catalyst increases the rate of reaction
 A catalyst allows the reaction to go by an alternative
pathway with lower activation energy
 More particles will have an energy greater than or equal
to the activation energy, therefore successful collision
rate increases resulting in increased rate of reaction
7.9 Light Causing a Chemical Reaction
 A photochemical reaction is one where light causes a
reaction to occur. The higher the light intensity the
higher the rate of the reaction.
 Photosynthesis: light provides energy for the reaction
and chlorophyll is a dye that absorbs light.
carbon dioxide + water → (light + chlorophyll) → glucose +
oxygen
6CO2 + 6H2O → (light + chlorophyll) → C6H12O6 + 6O2
PAGE 11 OF 22
CIE IGCSE CHEMISTRY//9093
 Silver salts in photographic film: Silver bromide breaks
down, where light strikes the film, so silver is reduced.
Silver ions are reduced to silver.
2AgBr(s) →2Ag(s)+Br2(g)
7.10 Reversible Reactions
 A reversible reaction is a reaction in which reactants
form products and the product(s) can then react or
decompose to form the reactants
 Example: CuSO4.5H2O (blue) ⇌ CuSO4(white) + H2O
 (to get anhydrous, heat it, & to get hydrated form, add
water)
 There are two types of equilibrium: static and dynamic.
 At dynamic equilibrium:
o Rate of forward reaction = rate of reverse reaction
o Concentrations of all reactants and products remain
constant
o System is closed, and on large scale everything is
constant
7.11 Equilibrium
 Potassium manganate is an oxidising agent and will go
from purple to colourless
 To test for an oxidising agent, add a reducing agent (KI)
and to test for a reducing agent, add an oxidising agent
(KMnO4)
8. ACIDS, BASES AND SALTS
8.1 Properties of Acids
 An acid is a compound which when dissolved in water
produces hydrogen ions (H+) and are described as proton
donors (H+)
 Acids turn blue litmus indicator paper (or solution) red.
 Have pH 1 to 6
 Acid + metal → salt + hydrogen gas
 Acid + base → salt + water
 Acid + metal carbonate → salt + carbon dioxide + water
 Strong acids completely ionize in water producing lots of
H+ ions
 Weak acids partially ionize in water producing few H+ ions
 Le Châtelier’s Principle: if conditions of an equilibrium
are changed, the position of equilibrium moves to
oppose change
 Temperature: Temperature lowered; equilibrium moves
in exothermic direction. Temperature raised; equilibrium
moves in endothermic direction.
 Pressure: Pressure raised; equilibrium moves to side
with fewest gas molecules. Pressure lowered;
equilibrium moves to side with most gas molecules.
 Concentration: Decreasing reactant concentration or
increasing product concentration; equilibrium moves to
reactant side. Increasing reactant concentration or
decreasing product concentration; equilibrium moves to
product side.
8.2 Properties of Bases
7.12 Redox
 Neutral substances are pH 7.
 Acidity in soil:
o Plants grow at a pH near 7.
o If it is too acidic or alkaline they will not grow.
o Acidic soil is fixed by adding lime.
 A redox reaction is one in which one species has been
oxidized and another species has been reduced
OXIDATION MEANS:
REDUCTION MEANS:
 Loss of electrons
 Gain of electrons
 Gain of oxygen
 Loss of oxygen
 Loss of hydrogen
 Gain of hydrogen
OIL RIG
 Reducing agents are oxidized and oxidizing agents are
reduced
 Potassium iodide is a reducing agent & will go from
colorless to red-brown, so is oxidized to produce I2
H2O2 + 2KI + H2SO4→I2 + K2SO4 + 2H2O
 Bases are insoluble substances which neutralize acids to
form a salt and water only and are proton acceptors
 Alkalis turn red litmus indicator paper (or solution) to
blue.
 Have pH 8 to 14.
 Base + acid → salt + water (+ CO2 when base is a metal
carbonate)
 Base + ammonium salt → salt + ammonia gas + water
 Strong alkalis completely ionize in water producing lots of
OH- ions
 Weak alkalis partially ionize in water producing OH- ions
8.3 Neutral
 pH is the concentration of H+ ions per dm3 of solution
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CIE IGCSE CHEMISTRY//9093
8.4 Indicators
8.9 Starting with an Insoluble Base
INDICATOR
COLOR IN ACID
Phenolphthalein
Methyl orange
Methyl red
Red litmus
Blue litmus
Colorless
Pink
Red
Red
Red
COLOR IN
ALKALINE
Pink
Yellow
Yellow
Blue
Blue
8.5 Types of Oxides
 Metal oxides are basic e.g. iron oxide and magnesium
oxide
 Non-metal oxides are acidic e.g. sulphur oxide and
carbon dioxide
 Aluminum, zinc and lead form amphoteric oxides e.g.
zinc oxide
 Oxides which are neither acidic or basic are neutral e.g.
water and carbon monoxide
8.6 Preparation of Salts
 A salt is a substance formed when all the replaceable
hydrogen ions of an acid are replaced by metal ions or
the ammonium ion
o Salts can either be soluble or insoluble
SOLUBLE SALTS
All sodium, potassium and
ammonium salts
All nitrates
Chlorides
Sulphates
Potassium, sodium and
ammonium carbonates
INSOLUBLE SALTS
Except silver and lead
Except barium, lead and
calcium
All other carbonates
8.7 Type of Salts
TYPE OF SALT REQUIRED
Sulphate
Nitrate
Chloride
Ethanoate
ACID USED
Sulphuric acid
Nitric acid
Hydrochloric acid
Ethanoic acid
 Add insoluble base to acid and heat gently, it will
dissolve
 Keep adding until no more dissolves (reaction is done)
 Filter out the insoluble (excess) base
8.10 Starting with an Alkali (Titration):
 Put a certain amount alkali in a flask
 Add phenolphthalein
 Add acid from a burette, stirring, until it goes colorless
 Find out how much acid you used
 Repeat, to be more accurate
 Evaporate water from neutral solution
8.11 Precipitation
 Mix the two soluble salts, so they react together
 Filter the mixture to separate the products produced
(soluble and insoluble salt produced)
 Wash the insoluble salt on the filter paper
 Dry the insoluble salt in a warm oven
8.12 Test for Aqueous Cations
EFFECT OF AQ.
CATION
NAOH
White soluble
ALUMINUM precipitate formed
(AL3+)
giving a colorless
solution
Ammonium gas
AMMONIUM
produced turns
(NH4+)
damp red litmus blue
CALCIUM
White precipitate
(CA2+)
formed
COPPER
(CU2+)
IRON(II)
(FE2+)
IRON(III)
(FE3+)
8.8 Starting with a Metal

Add excess metal to an acid
 When bubbling (hydrogen) stops the reaction is done
 Filter off excess metal
ZINC (ZN2+)
PAGE 13 OF 22
EFFECT OF AQ.
AMMONIA
White precipitate
formed
No precipitate/ slight
white precipitate
Light blue soluble
Light blue precipitate precipitate formed
formed
giving dark blue
solution
Green precipitate
Green precipitate
formed
formed
Red-brown
Red-brown
precipitate formed precipitate formed
White soluble
White soluble
precipitate formed precipitate formed
giving a colorless
giving a colorless
solution
solution
CIE IGCSE CHEMISTRY//9093
8.13 Test for Anions
9.2 Alkali Metals
ANION
TEST
TEST RESULT
CARBONATE Add dilute nitric acid Bubble gas through
(CO32-)
limewater–from
colorless to cloudy
CHLORIDE Add nitric acid, then White precipitated
(CL-)
aqueous silver nitrate formed
BROMIDE Add nitric acid, then Cream precipitate
(BR-)
aq. silver nitrate
formed
IODIDE (I ) Add nitric acid, then Bright yellow
aqueous silver nitrate precipitate formed
NITRATE
Add aqueous sodium Gas produced turns
(NO3 )
hydroxide then add damp red litmus
aluminum
paper blue
SULPHATE Add dilute nitric acid, White precipitate
(SO42-)
then add aq. barium formed
nitrate
 Lithium, sodium and potassium
8.14 Test for Gases
Patterns
 Reactivity, density & softness increases down the group
 Melting and boiling points decreases down the group.
 Reactivity increases as more electron shells means there
is weaker attraction between nucleus & valency electron
so is lost more easily.
GAS
Ammonia (NH3)
Carbon dioxide
(CO2)
Chlorine (Cl2)
Hydrogen (H2)
Oxygen (O2)
TEST AND TEST RESULT
Damp red litmus paper turns blue
Bubble gas through–from colorless
to cloudy
Bleaches red/blue litmus paper
Place lighted splint, squeaky pop
Place glowing splint, splint relights
9. THE PERIODIC TABLE
 The Periodic table is a method of classifying elements.
 They are arranged in order of increasing atomic number.
 Made up of rows called periods and columns called
groups
 Metals are to the left and non-metals are to the right.
 Elements in the same group have similar properties.
 Group number tells us the number of valency electrons
and the period number tells us about the number of
electron shells
9.1 Periodic Trends
 Non-metals are on the right side of the periodic table,
and metals are on the left.
 Down a period of metals they become more reactive
 With non-metals, going down a period, the non-metal
becomes less reactive
CHEMICAL PROPERTIES
 Form ionic compounds
 React violently with
chlorine
 Burst into flames when
heated with oxygen:
O A red flame for
lithium
O A yellow flame for
sodium
O A lilac flame for
potassium
 Produce soluble white
compounds.
 React with cold water.
PHYSICAL PROPERTIES
 Good conductors of
heat and electricity.
 Are soft, compared to
other metals.
 They have low densities
for metals.
 They have low melting
and boiling points
compared to most
metals.
9.3 Halogens
PROPERTIES
PATTERNS
 Form colored gases, at
 Down the group; size,
RTP:
mass and density
o Fluorine is a yellow gas increases
o Chlorine is a green gas  Down the group, color
o Bromine is a red liquid darkens
o Iodine is a black solid  Reactivity decreases down
 Are poisonous
the group, because it has
 Brittle and crumbly when to gain an electron, so the
solid
closer the electron is to
 Do not conduct electricity the positive nucleus the
 Form diatomic molecules more easily it will be
gained, so atoms with
fewer shells
 Will react more easily.
9.4 Transition Metals
 High melting points (except mercury)
 Malleable and ductile
 Good conductors of heat & electricity (silver is the best)
 High density
 Have no trend in reactivity
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CIE IGCSE CHEMISTRY//9093
 Can be used as catalysts
 Form colored compounds
 Can form complex ions as they have variable valences
9.5 Noble Gases
PROPERTIES
 Density increases down
the group
 M.p. and b.p. increases
down the group
 Don’t conduct
electricity
 Don’t take part in
chemical reactions
USES
 Helium- filling balloons
and aircrafts because it
is lighter than air and
will not catch fire.
 Argon – filling (tungsten)
light bulbs to stop the
filament reacting with
oxygen.
 Neon – is used in
advertising signs
because it glows red.
10. METALS
10.1 Properties of Metals
PHYSICAL
 High density
 Shiny when polished
 Malleable
 Ductile
 High m.p. And b.p.
 Conductor of heat &
electricity
CHEMICAL
 Form basic oxides
 Form positive ions
 An alloy is two or more metals, or a metal and non-metal
which have been made molten and then mixed together
 Alloys are used because they have improved qualities for
a particular job over the pure metals
Brass
MADE FROM
Copper and
zinc
Bronze
Copper and
tin
Stainless
steel
Iron,
chromium
and nickel
10.3 Reactivity Series
K - Potassium
Na - Sodium
Ca – Calcium
Mg –
Magnesium
Al – Aluminum
C – Carbon
Zn – Zinc
Fe – Iron
Pb – Lead
H – Hydrogen
Cu – Copper
Ag – Silver
Au – Gold
 This places metals in order of their
readiness to take part in chemical
reactions
 Everything above hydrogen can
displace hydrogen from its acid,
and hydrogen cannot reduce their
oxides.
 Metals above carbon, their oxides
cannot be reduced by carbon.
 More reactive metals will react
with cold water, and less reactive
will react slowly or not react with
steam.
 Aluminum seems unreactive
because it forms an oxide layer
which protects it
10.4 Displacement Reactions
10.2 Alloys
ALLOY
 Metals are often used as alloys because they have an
increased range of uses and mixture of atoms gives an
irregular structure which stops layers sliding over each
other easily; they are stronger
 This is what the structure of an alloy (a) looks like,
compared to a pure metal (b).
SPECIAL
PROPERTIES
Stronger and
more
resistant to
corrosion
Harder,
stronger and
sonorous
Does not rust
USES
Electrical
fittings, car
radiators
 These are reactions in which metals compete for oxygen
or anions
 The more reactive metal will displace the less reactive
metal from oxygen or an anion.
 If more reactive metal has oxygen or an anion, no
reaction occurs
 The bigger the difference in reactivity between the two
metals, the faster the reaction
10.5 Thermal Decomposition
GROUP
Statues,
Group I
springs, coins
(except
lithium)
Kitchen sinks,
Group II,
cutlery,
lithium &
chemical
transition
plant
metals
PAGE 15 OF 22
METAL
CARBONATE
METAL
METAL NITRATE
HYDROXIDE
Do not
decompose
Do not
Metal nitrite and
decompose
oxygen
Metal oxide
and carbon
dioxide
Metal oxide,
Metal oxide
nitrogen dioxide
and water
and oxygen
CIE IGCSE CHEMISTRY//9093
10.6 Extraction of Metals
Reduction via
electrolysis
CARBON
Reducing via heating
with Carbon or Carbon
Monoxide
HYDROGEN
Cu – Copper
Ag – Silver
Au – Gold
Occur naturally
More powerful/expensive method of extraction
Zn – Zinc
Fe – Iron
Pb – Lead
EXTRACTION METHOD
Ores more difficult to decompose
METAL
K - Potassium
Na - Sodium
Ca – Calcium
Mg –
Magnesium
Al – Aluminum
10.9 Extracting Zinc
10.7 Extracting Iron
 Ore = hematite (Fe2O3)
 Uses of slag
o To make roads
o To make cement
 Coke burns with air
carbon + oxygen  carbon dioxide
 Carbon dioxide reacts with
coke
carbon dioxide + carbon 
carbon monoxide
 Ore = Zinc Blende = Zinc Sulphide (ZnS)
 Zinc blende is roasted in air to convert it to zinc oxide
 Zinc oxide is reduced using coke to zinc and carbon
monoxide in the furnace
 As zinc is volatile, the gaseous metal is distilled leaving
less-volatile impurities behind.
Zinc is condensed and liquid is run into mould.
10.10 Uses of Metal
 Aluminum
o Airplane/Cars (Strong/Low density/resistant to
corrosion)
o Cans/Foil (Resistant to corrosion/malleable)
o Overhead cable (Good conductor of
electricity/ductile)
 Zinc
o Galvanizes Iron = coats it to stop it rusting
o Alloys – brass/bronze
o Batteries
o Sacrificial Protection
 Copper
o Electrical Wiring (Good conductor of
electricity/Ductile)
o Cooking utensils (Malleable/good conductor of heat)
o Roofs (hard wearing against weather
11. AIR AND WATER
 Carbon monoxide reduces Iron(III) oxide to iron
11.1 Tests for Water
iron(III) oxide + carbon monoxide  iron + carbon dioxide
 The limestone reacts with impurities to form slag
calcium carbonate + silicon dioxide  calcium silicate + carbon dioxide
10.8 Iron to Steel
 Molten iron from blast furnace is poured into an oxygen
furnace.
 Calcium oxide is added, and a jet of oxygen is turned on.
 The calcium oxide neutralizes acidic impurities, forming
slag that is skimmed off and oxygen burns the other
impurities away.
 The carbon content is checked continually until it is just
right then the oxygen is turned off.
o Mild Steel (0.25% carbon) – Used in machinery and
car bodies
o Medium carbon steel (0.5%) – Used in railway lines
o High carbon steel (1.5% carbon) – Used in knives and
blades
TEST
Blue Cobalt(II)
Chloride Paper
Anhydrous
Copper(II)
Sulphate powder
Test m.p. and b.p.
TYPE OF TEST
Chemical
Chemical
Physical
POSITIVE RESULT
Paper turns from
blue to pink
From white
powder to blue
crystals
m.p. at 0°C and
b.p. at 100°C
11.2 Purification of Water
 Water is pumped into screens, which remove solid
floating debris.
 Aluminum sulfate is added to coagulate (stick together)
small pieces of clay so that they are easily removed.
 The water is then filtered through coarse sand to remove
larger, insoluble debris.
 The water encounters more flocculants (chemicals that
make particles move down to bottom of tank) and is
filtered again through fine sand.
PAGE 16 OF 22
CIE IGCSE CHEMISTRY//9093
 Chlorine gas is bubbled through the water to kill
bacteria. This makes the water slightly acidic, so to
reverse this appropriate amounts of sodium hydroxide
(an alkali) is added.
 Some countries also add fluorine
11. 3 Use of Water
AT HOME
 Drinking
 Cooking
 Washing
 On farms for animals &
crops
IN INDUSTRY
 Dissolve
 wash and cool things
 In power stations where
steam is used to turn
turbines
11.7 Catalytic Convertor
11.4 Air
 In the combustion engine, insufficient amounts of
oxygen lead to incomplete combustion of the carbon
containing fuel
 Gases produced: (a) carbon monoxide (b) oxides of
nitrogen
 A catalytic convertor catalyzes the reduction of NO2 to
nitrogen gas N2 and catalyzes the oxidation of CO to CO2
 Clean air is composed of approximately
o 79% nitrogen
o 20% oxygen
o Remainder: noble gases, water vapor & carbon
dioxide
11.5 Pollutants in Air
POLLUTANT
 It is compressed, causing it to heat up. Cooled by
recycling cold air
 The cold compressed air is passed through a jet, into a
larger space. It expands rapidly, making it very cold.
 This is repeated, cooling the air more. By -200°C it is
liquid except for neon and helium. These gases are
removed. They can be separated from each other by
absorption on charcoal.
 The liquid air is pumped into the fractioning column.
There it is slowly warmed up. The gases boil off one by
one, and are collected in tanks or cylinders.
 Sources of methane: oil and natural gas, decomposition
of vegetation, and waste gases from digestion in animals
SOURCE
PROBLEMS CAUSED
Reacts with
Incomplete
haemoglobin,
Carbon
combustion of
preventing it from
Monoxide
carbon-containing
carrying oxygen;
CO
substances
death due to oxygen
starvation
Irritates eyes and
Sulphur
From combustion of
throat, causes
Dioxide
fossil fuels which
respiratory problems
SO2
contain sulfur
and causes acid rain
Oxides of
Causes respiratory
Nitrogen
From car exhausts problems and forms
NOx
acid rain
From burning of
Causes damage to
Lead
petrol as lead is
brain and nerve cells
compounds added to it for better
in young children
performance
11.8 Rust Preventition
 Coating with something to prevent contact with air and
moisture
o Plastic, paint and grease
o Electroplating with tin or chromium
o Galvanising: dipping in molten zinc
 Sacrificial protection: attaching a piece of metal that is
more reactive that iron to object, commonly magnesium
or zinc. This will corrode in the place of iron.
11.9 Fertilizer
 NPK used in fertilizers because:
o Nitrogen is needed for chlorophyll and other proteins.
o Phosphorus helps roots grow and crops ripen.
o Potassium helps make proteins and resist diseases.
 All alkalis (except ammonia) will react with ammonium
compounds, removing ammonia, for example:
 ℎ +  ℎ →  ℎ +  + 
11.10 Greenhouse Gases
11,6 Fractional Distillation of Air
 Air is filtered to remove dust
 Water vapor and carbon dioxide removed, (because they
would freeze and block the pipes):
o air is cooled until water vapor condenses
o then passes over absorbent beads to trap carbon
dioxide
 The greenhouse gases are: carbon dioxide and methane.
 They stop heat escaping in to space.
 Too much greenhouse gases leads to climate change.
 This will cause the ice poles to melt, rising sea levels,
more droughts, storms, floods and famine; global
warming
PAGE 17 OF 22
CIE IGCSE CHEMISTRY//9093
11.11 Formation of Carbon Dioxide
12.2 Uses
 Carbon dioxide is produced whenever carbon or any of
its compound are completely burned in excess oxygen
 It is also formed as a product of respiration
 It is produced as product of reaction between an acid
and carbon
 From the thermal decomposition of a carbonate
11.12 Haber Process
 Industrial manufacture of ammonia NH3
N2 (g) + 3H2 (g) ⇌ 2NH3 (g)
 Raw materials:
o Nitrogen: from the air
o Hydrogen: methane + steam → carbon dioxide +
hydrogen
 Essential conditions:
o Temperature: 450°C
o Pressure: 200atm
o Catalyst: Iron
11.13 Carbon Cycle
SULFUR
 As a food preserver; kills
bacteria
 As a bleach in the
manufacture of wood
pulp for paper
 In car batteries as
electrolyte
 In manufacture of
sulphuric acid (through
Contact process)
SULFUR DIOXIDE
 Manufacture of
sulphuric acid
 To bleach wool, silk and
wood pulp for making
paper
 As a sterilising agent in
making soft drinks and
jam, and in drying fruit;
stops growth of bacteria
and moulds.
12.3 Contact Process
 Sulphur is first burned in air producing sulphur dioxide
 It is then mixed with more air and passed over four
separate beds of catalyst, Vanadium (V) oxide, at 450°C
to form sulphur trioxide
 It is then dissolved in concentrated sulphuric acid
forming a thick fuming liquid called oleum
 It is then mixed carefully with water to form
concentrated sulphuric acid.
 Essential conditions:
o Catalyst: Vanadium (V) oxide
o Temperature: 450°C
o Pressure: 2atm
12.4 Properties of Sulfuric Acid
 Forms salts called sulphates
 When concentrated, it’s a dehydrating agent, and a thick
oily liquid
 It turns blue litmus red
 It is a strong acid and has the properties of a typical
strong acid: reacts with bases, low pH, high conductivity
13. CARBONATES
12. SULFUR
12.1 Sources
 Found as an element, in large underground beds
 Found around the rims of volcanoes.
 It occurs in metal ores e.g. lead sulphide
 Sulphur compounds also occur naturally in the fossil
fuels e.g. coal
 Lime is manufactured by limestone by heating
 CaC03 + heat → CaO + CO2
PAGE 18 OF 22
CIE IGCSE CHEMISTRY//9093
 Uses of quick lime:
o Making steel from iron
o To neutralise acidity in soil
o Drying agent in industry
 Uses of slaked lime and lime:
o Neutralise acidity in soil, and in lakes affected by acid
rain,
o Neutralising acidic industrial waste products, e.g. flue
gas desulphurisation
 Uses of limestone:
o Making cement: made by mixing limestone with clay,
heating mixture strongly in a kiln, adding gypsum
(calcium sulphate), and grinding up the final solid to
give a powder
o Making iron from iron ore: limestone reacts with
sand) forming slag (calcium silicate), which is then
used for road building.
14.4 Name of Compounds
Name ending → compound-type name
 “ane” → alkane
 “ene” → alkene
 “ol” → alcohol
 “oic acid” → carboxylic acid
 “yl”, “oate” → ester
14.5 Alkanes
General formula = CnH2n+2
METHANE (N=1)
ETHANE (N=2)
PROPANE (N=3)
BUTANE (N=4)
14. ORGANIC CHEMISTRY
14.1 Homologous Series
 Homologous series: ‘family’ of similar compounds with
similar properties due to the presence of the same
functional group.
 Characteristics of a homologous series:
o all the compounds fit the same general formula
o the chain length increases by 1 each time
o as the chain gets longer, the compounds show a
gradual change in properties
 Structural isomers: have the same chemical formula, but
different structures, they can be straight or branched
14.2 Fuels
 Fuels to know:
o Coal
o Natural gas: main constituent is methane
o Petroleum: a mixture of hydrocarbons which can be
separated into fractions
14.3 Uses of Petroleum Fractions
 Refinery gas: bottled gas for heating and cooking
 Gasoline fraction: fuel (petrol) in cars
 Naphtha fraction: making chemicals
 Kerosene/paraffin fraction: jet fuel, lamps
 Diesel oil/gas oil fraction: fuel in diesel engines
 Fuel oil fraction: fuel in ships and home heating systems
 Lubricating fraction: lubricants, waxes and polishes
 Bitumen: making roads
 Each carbon atoms in an alkene has four covalent single
bonds – this makes them quite unreactive.
Combustion:
 Complete combustion: enough oxygen supply so water
and carbon dioxide form.
 e.g. CH4 + 2O2 → CO2 + 2H2O
 Incomplete: is not enough oxygen to burn them cleanly
so either carbon monoxide and water or carbon and
water form.
e.g. 2CH4 + 3O2 → 2CO + 4H2O
or
e.g. CH4 + O2 → C + 2H2O
Chlorine substitution:
 Sunlight or light is necessary
 A chlorine atom replaces a hydrogen atom
 This can happen to all hydrogen atoms if there is enough
chlorine.
e.g. CH4 + Cl2 → (light) → HCl + CH3Cl / CH2Cl2 / CHCl3 /
CCl4
Compounds = chloromethane / di/tri/tetrachloromethane
PAGE 19 OF 22
CIE IGCSE CHEMISTRY//9093
14.6 Alkenes
14.8 Alkenes’ Addition Reactions
 With bromine: (the test for saturation)
e.g. ethene (g) + bromine (aq) → 1,2-dibromomethane
(l)
 With steam: forms alcohols with heat, pressure and a
catalyst
e.g. ethene (g) + steam (g) ⇌ ethanol (l)
 With hydrogen: double bond breaks down to for an
alkane with heat, pressure and a catalyst
e.g. ethene (g) + hydrogen (g) → ethane (g)
General formula = CnH2n
Functional group: C=C bond
(N=1)
N/A
ETHENE (N=2)
PROPENE (N=3)
BUT-1-ENE (N=4)
14.9 Alcohols
Cracking:
 Thermal decomposition reaction, in which an alkene
(and sometimes hydrogen) are produced from an
alkane.
 Cracking always produces short chain compound with a
C=C bond
e.g. Cracking of ethane will give ethene and hydrogen
General formula = CnH2n+1OH
Functional group: OH
METHANOL (N=1)
ETHANOL (N=2)
PROPANOL (N=3)
BUTANOL (N=4)
Formed by:
FERMENTATION
 Butane → Ethane + Ethene ; C4H10 → C2H6 + C2H4
SATURATED
HYDROCARBONS
 Have NO double bonds
 Do not react with
aqueous bromine, so
the mixture stays
orange.
UNSATURATED
HYDROCARBONS
 Have double bonds
 React with aqueous
bromine, turning the
mixture from orange to
colourless.
14.7 Addition Polymerisation
 A polymer is a compound with very long carbon chains
made up of monomer units.
 Poly(ethene) / Polythene: is a polymer produced from
ethene by addition polymerization
 Enzymes in yeast break
down glucose to ethanol
and carbon dioxide,
giving out heat
 Can be done with
substances that contain
cellulose, starch or
glucose
 Done by grinding source
(e.g. grapes) and adding
enzymes to break down
cellulose and starch into
glucose.
 Leave it to ferment.
 Fractional distillation is
used to get ethanol from
the mixture
Double bond splits and polymer is formed
PAGE 20 OF 22
CATALYTIC ADDITION OF
STEAM TO ETHENE
 Ethene is obtained by
cracking long-chain
alkenes from oil.
 The ethene reacts with
steam (reversibly) in the
following conditions:
o 570°C
o 60-70atm
o Catalyst = phosphoric
acid
 Low temperature gives a
better yield, but high
temperature is used to
give a better rate of
reaction.
14.10 Carboxylic Acids
General formula = CnH2n+1COOH
Functional group: COOH
METHANOIC ACID (N=1)
ETHANOIC ACID (N=2)
PROPANOIC ACID (N=3)
BUTANOIC ACID (N=4)
Properties of Ethanoic Acid:
 Weak acid with high pH and low dissociation
 Formed by:
o Oxidation of ethanol
o With acidified potassium mangenate (VII)
 Carboxylic acids react with alcohols to give esters, in a
condensation reaction, for example:
 Ethanoic acid + ethanol ⇌ ethyl ethanoate + water
(alcohol = -yl & carboxylic acid = -oate)
 Large molecules built up from small units (monomers).
 Different macromolecules have different units and/or
different linkages
Example of:
POLYTHENE
SMALL UNITS
(MONOMERS)
 glucose
 amino acids
 fatty acids
and glycerol
POLYCHLOROE
THANE (PVC)
 Oil is a non-renewable
resource
 Lot of energy to make
steam and get right
conditions
 Lot of ethene is unreacted, (and then
recycled)
 Ethanol burns well in oxygen, giving out plenty of heat,
as well as carbon dioxide and water.
 Ethanol is used as a:
o Solvent: to dissolve things than water cannot.
Evaporates easily, so used as solvent in glues, printing
inks & perfumes
o Fuel: added to or instead of petrol, because it burns
cleanly
FROM ETHENE
 Fast
 Continuous process
 Pure ethanol
 Smaller containers
14.11 Macromolecules
POLYPROPENE
DISADVANATGES
 Lots of material needed
so big tanks needed
 Fractional distillation is
expensive
 Slow process
 Batch process
POLYSTYRENE
ADVANTAGES
 Renewable source
 Good use of waste
organic material
TEFLON
FERMENTATION
CIE IGCSE CHEMISTRY//9093
LINKAGES
 amide
 ester
USE
 Plastic bags and
gloves, clingfilm (low
density), mugs, bowls,
chairs, dustbins (high
density)
 Water pipes,
wellingtons, hoses,
covering for electricity
cables
 Crates, ropes
 Used as expanded
polystyrene in fastfood cartons,
packaging, and
insulation for roofs
and walls
 Coated on frying pans
to make them nonstick, fabric protector,
windscreen wipers,
flooring
PAGE 21 OF 22
MACROMOLECULES
 protein
 starch
 lipids
STRUCTURE
CIE IGCSE CHEMISTRY//9093
 They collect in rivers, and get in the way of fish. Some
river beds now contain a thick layer of plastic
 They blow into trees and onto beaches. So the place
looks a mess. Tourists become put off.
Making nylon:
 Uses: ropes, fishing nets and lines, tents, curtains
 Monomers are:
14.13 Natural Macromolecules
 Food’s main constituents are proteins, fats and
carbohydrates.
Proteins:
 Proteins contain the same linkages (amide links) as
nylon, but with different units. Their structure is:
 No double bonds break, instead single bonds break, and
new single bonds form.
 The monomers are able to join to each other by
eliminating a small molecule: hydrogen chloride.
 This reaction continues at each the two monomers.
 Thousands of molecules join together, giving a
macromolecule:
Making terylene
 Uses: clothing (especially mixed with cotton), thread
 Monomers are:
 In digestion proteins are broken down into amino acids
(hydrolysis).
Fats:
 Fats are esters possessing the same linkage as Terylene
(ester links) but with different units.
 Soap is a product of the hydrolysis of fat. It is done using
sodium hydroxide (as opposed to acid, in digestion). The
hydrolysis gives glycerol and the sodium salts of fatty
acids. The salts are used as soaps.
Carbohydrates:
 Complex carbohydrates: are a large number of joined
sugar units (monosaccharide like glucose). The sugar
units are represented like this:
They join together in a condensation polymerization
 The monomers join by eliminating a water molecule.
Thousands of molecules join up, giving a macromolecule
14.12 Pollution from Plastics
 Choke birds, fish and other animals that try to eat them.
Or they fill up the animals’ stomachs so that they can’t
eat proper food, and starve to death.
 They clog up drains and sewers and cause flooding.
 In digestion, the hydrolysis (Decomposition of a chemical
compound by reaction with water) of starch happens in
the mouth by the enzyme amylase to make glucose
 Hydrolysis:
o Starch → glucose
o Proteins → amino acids
o Fats → fatty acids and glycerol
 But if hydrolysis is not complete, macromolecules are
not completely broken down so you get a mixture of
molecules of different sizes
 Identification:
o Chromatography can be used to identify products &
substances
o However, amino acids and sugars are colourless when
dissolved in water, so a locating agent is used.
o Substances can be identified using Rf values or by
matching them with spots which are horizontal
PAGE 22 OF 22
TABLE OF CONTENTS
2
CHAPTER 1
3
CHAPTER 2
4
CHAPTER 3
6
CHAPTER 4
7
CHAPTER 5
7
CHAPTER 6
Number
Algebra & Graphs
Geometry
Mensuration
Coordinate Geometry
Trigonometry
8 Matrices & Transformations
CHAPTER 7
9
CHAPTER 8
9
CHAPTER 9
Probability
Statistics
CIE IGCSE MATHEMATICS//0580
Set representations:
1. NUMBER
 Natural numbers:
o used for counting purposes
o made up off all possible rational & irrational numbers
 Integer: a whole number
 Prime numbers:
o divisible only by itself and one
o 1 is not a prime number
 Rational numbers: can be written as a fraction
 Irrational numbers: cannot be written as a fraction e.g.
1.1 HCF and LCM
 Highest Common Factor and Lowest Common Multiple:
o HCF = product of common factors of x and y
o LCM = product of all items
in Venn diagram
 Prime Factorization: finding
which prime numbers
o multiply together to make
the original number
∈
 ∪  is shaded
= {a, b, c, d, e}
 Definition of sets e.g.
o  = {:  is a natural number}
o  = {(, ):  =  + }
o  = {:  ≤  ≤ }
o  = {, , , … }
Notation:
 () = no. of elements in A   ⊆  = A is a subset of B
 ∈ = …is an element of…
  ⊂  = A is a proper
 ∉ = …is not an element of… subset of B
 ′ = compliment of set A   ⊈  = A is not a subset
of B
 Ø or { } = empty set
  ⊄  = A is not a proper
 = Universal set
subset of B
  ∪  = union of A and B
⊂ ‘is a subset of’
A’ is shaded
1.3 Indices
 () = no. of elements in A   ⊆  = A is a subset of B
 ∈ = …is an element of…
  ⊂  = A is a proper
 ∉ = …is not an element of… subset of B
 ′ = compliment of set A   ⊈  = A is not a subset
of B
 Ø or { } = empty set
  ⊄  = A is not a proper
 = Universal set
subset of B
  ∪  = union of A and B
  ∩  = intersection of A
and B
Standard form:
o 104 = 10000
o 103 = 1000
o 102 = 100
o 101 = 10
o 100 = 1
1.2 Sets
  ∩  = intersection of A
and B
 ∩  is shaded
10−1
10−2
10−3
10−4
10−5
= 0.1
= 0.01
= 0.001
= 0.0001
= 0.00001
Limits of accuracy:
 The degree of rounding of a number
o E.g. 2.1 to 1 d.p.
2.05 ≤  < 2.15
1.4 Ratio & Proportion
 Ratio: used to describe a fraction
o e.g. 3 : 1
 Foreign exchange: money changed from one currency to
another using proportion
o E.g. Convert $22.50 to Dinars
$1 : 0.30KD
$22.50 : 6.75KD
 Map scales: using proportion to work out map scales
o 1km = 1000m
o 1m = 100cm
o 1cm = 10mm
PAGE 2 OF 10
CIE IGCSE MATHEMATICS//0580
 Direct variation:  is proportional to 
∝
 = 
 Inverse variation:  is inversely proportional to 
1
∝
 Trinomial:
 2 + 14 + 24
 + 12 + 2 + 24
( + 12) + 2( + 12)
( + 2)( + 12)
2

=
1.5 Percentages
 Percentage:
o Convenient way of expressing fractions
o Percent means per 100
 Percentage increase or decrease:
 
  =
 
 Simple interest:

=
100
 = 
 =   
 =   
 Compound interest:
 =   
 =   
1.6 Speed, Distance & Time


 
  =
 
 Units of speed:
km/hr m/s
 Units of distance:
km
m
 Units of time:
hr
sec
5
/ℎ ×
= /
18
18
/ ×
= /ℎ
5
 =
2. ALGEBRA & GRAPHS
2.1 Factorisation
 Common factors:
3 2 + 6
3( + 2)
 Difference of two squares:
25 −  2
(5 + )(5 − )
 Group factorization:
4 +  +  + 4
4( + ) + ( + )
(4 + )( + )
 General equation:
 2 +  +  = 0
 Solve quadratics by:
o Trinomial factorization
o Quadratic formula
− ± √ 2 − 4
=
2
 When question says “give your answer to two decimal
places”, use formula!
2.3 Simultaneous Equations
 
 =  (1 +
)
100
 = 
2.2 Quadratic Factorization
 Simultaneous linear equations can be solved either by
substitution or elimination
 Simultaneous linear and non-linear equations are
generally solved by substitution as follows:
o Step 1: obtain an equation in one unknown and solve
this equation
o Step 2: substitute the results from step 1 into the
linear equation to find the other unknown
 The points of intersection of two graphs are given by the
solution of their simultaneous equations
2.4 Inequalities
 Solve like equations
 Multiplying or dividing by negative ⇒ switch sign

≥ −7
−3
 ≤ −7 × −3
 ≤ 21
 When two inequalities present, split into two
 < 3 − 1 < 2 + 7
 < 3 − 1
3 − 1 < 2 + 7
1
 > −2
<8
2.4 Linear Programming
 For strict inequalities (<, >) use broken line
 For non-strict inequalities (≤, ≥) use solid line
PAGE 3 OF 10
CIE IGCSE MATHEMATICS//0580
 Steps to solve:
o Interpret  =  + 
o Draw straight line graphs
o Shade
o Solve
2.5 Sequences
 Linear sequences: Find common difference e.g. 3 then
multiply by  and work out what needs to be added
 Quadratic sequences:
o Format: 2 +  + 
++ =
3 +  =
2 =
o Work out the values and then place into formula to
work out nth term formula
 Geometric progression: sequence where term has been
multiplied by a constant to form next term
ℎ   . . =  (−1)
o a = 1st term r = common difference
2.6 Distance-Time Graphs
 Area under a graph = distance travelled.
 Gradient = acceleration.
 If the acceleration is negative, it is called deceleration or
retardation. (moving body is slowing down.)
2.8 Functions
 Function notation:
o :  → 2 − 1
o Function  such that  maps onto 2 − 1
 Composite function: Given two functions () and
(), the composite function of  and  is the function
which maps  onto (())
 (2)
o Substitute  = 2 and solve for ()
 ()
o Substitute  = ()
  −1 ()
o Let  = () and make  the subject
3. GEOMETRY
3.1 Triangles
 From O to A : Uniform speed
 From B to C : Uniform speed (return journey)
 From A to B : Stationery (speed = 0)
 Gradient = speed
2.7 Speed-Time Graphs
 From O to A : Uniform speed
 From A to B : Constant speed (acceleration = 0)
 From B to C : Uniform deceleration / retardation
3.2 Quadrilaterals
 Rectangle: Opposite sides
parallel and equal, all angles
90°, diagonals bisect each
other.
 Parallelogram : Opposite sides
parallel and equal, opposite
angles equal, diagonals bisect
each other
PAGE 4 OF 10
CIE IGCSE MATHEMATICS//0580
 Rhombus: A parallelogram with
all sides equal, opposite angles
equal, diagonals bisect each
other
 The number of times shape fits its outline during a
complete revolution is called the order of rotational
symmetry.
 Trapezium: One pair of sides
parallel
 Kite: Two pairs of adjacent sides
equal, diagonals meet at right
angles bisecting one of them
3.3 Construction
 Constructing triangles:
 Perpendicular bisector:
Shape
Square
Rectangle
Parallelogram
Rhombus
Trapezium
Kite
Equilateral triangle
Regular hexagon
Number of Lines
Rotational
of Symmetry
Symmetry Order
4
4
2
2
0
2
2
2
0
1
1
1
3
3
6
6
 Properties of circles:
o Equal chords are equidistant from the centre
o The perpendicular bisector of a chord passes through
the centre
o Tangents from an external point are equal in length
3.5 Polygons
 Sum of angles at a point = 360
 Angles on a straight line = 180
 Sum of angles in a triangle =180
 For regular polygon
o External angles =
 Angle bisector:
360

o Internal angles = 180 −
360

 For irregular polygon:
o Sum of exterior angles =360
o Sum of interior angles =180(n-2)
 Vertically opposite angles
 Corresponding angles
3.4 Symmetry
 A line of symmetry divides a two-dimensional shape into
two congruent (identical) shapes.
 A plane of symmetry divides a three-dimensional shape
into two congruent solid shapes.
PAGE 5 OF 10
CIE IGCSE MATHEMATICS//0580
 Alternate angles
3.7 Loci
 The locus of points equidistant from a point is a circle
 Co-interior angles
 The locus of points equidistant between two point is a
perpendicular bisector
 Exterior angle=sum of interior opposite ∠
3.6 Circle Theorem
 The locus of points equidistant between two lines is an
angle bisector
Angle at centre = twice
angle on circumference
Angle subtended by same
arc at circumference are
equal
 The locus of points equidistant (along) from a line is a
parallel line
Angles in semicircle are 90°
Opposite angles in a cyclic
quadrilateral = 180°
4. MENSURATION
4.1 Area
 Parallelogram =  × ℎ
Tangents from one point are
equal ∠ between tangent Alternate segment theorem
and radius is 90°
1
 Triangle= 2  × ℎ
1
 Trapezium= 2 ( +
2
 Circle= 

 Sector=  2 × 360
PAGE 6 OF 10
)ℎ
OR
 sin 
CIE IGCSE MATHEMATICS//0580
4.2 Volume and Surface Area
 Cylinder
o    = 2ℎ
o  =  2 ℎ
 Cone
o    = 
 Equation of Line:
 =  + 
o Find the gradient, 
o Find the -intercept, 
1
o  = 3 ( 2 ℎ)
 Sphere
o   = 4 2
4
o  = 3  3
 Hemisphere
o   = 2 2
 Midpoint of Graph:
1 + 2 1 + 2
(
,
)
2
2
 Length between two points:
2
o  = 3  3
4.3 Units
√(1 − 2 )2 + (1 − 2 )2
 Volume:
5.2 Sketching Graphs
 Mass:
() = 1
() = 
() =  3
() =
() =  2
 Capacity:
 Connecting volume and capacity:
o 1 = 13
o 1 = 13

 Density =

5. COORDINATE GEOMETRY
5.1 Graphs
 Gradient of a Straight Line:
 =
1

() =
1
2
6. TRIGONOMETRY
6.1 Bearings
 The bearing of a point B from another point A is:
o An angle measured from the north at A.
o In a clockwise direction.
o Written as three-figure number (i.e. from 000 ° to 360°)
 e.g. The bearing of B from A is 050°
2 − 1
2 − 1
PAGE 7 OF 10
CIE IGCSE MATHEMATICS//0580
 Multiplication by a scalar:
o A scalar quantity has a magnitude but no direction
o The negative sign reverses the direction of the vector
 Column vector:
o Top number is the horizontal component and
bottom number is the vertical component
 Parallel vectors:
o Vectors are parallel if they have the same direction
o In general the vector () is parallel to ()
 Modulus of a vector:
o In general, if  = (
), || = √(2 + 2

6.2 Pythagoras Theorem
 To find hypotenuse
o 2 +  2 =  2
 To find one of the shorter sides
o 2 =  2 −  2
o  2 =  2 − 2
 Angle of elevation:
o Angle above the horizontal
line.
 Angle of depression:
o Angle below the
horizontal line.
7.2 Matrices
 Addition:
 
+ +
 
(
)+(
)=(
)
 
 
+ +
 Multiplication by scalar
 
 
(
)=(
)
 
 
 Multiplication by vector:
 +   + 
 
 
(
)×(
)=(
)
 
 +   + 
 
o You can only multiply if no. of columns in left equals to
no. of rows in right
 Determinant:
o Determinant = leading diagonal – secondary diagonal
 
A =(
) || = () − ()
 
 Inverse:
o To work out inverse, switch leading diagonal, negate
1
2
 Area of a triangle:  sin 
6.3 Ratios
 Right angled triangles:

o sin  = ℎ

o cos  = ℎ

o tan  = 
6.4 Sine & Cosine Rules
 Sine rule:



=
=
sin  sin  sin 
o One pair of information needed
 Cosine rule
o To find the angle given 3 sides
 2 +  2 − 2
cos  =
2
o To find side given angle and two sides
2 =  2 +  2 − 2 cos 
1
secondary diagonal, multiply by ||

A =(


)

1

−1 = (−) (
−
−
)

7.3 Transformation
7. MATRICES & TRANSFORMATION
7.1 Vector
 A vector quantity has both magnitude
and direction.
o E.g. Vectors a and b represented by the line segments
can be added using the parallelogram rule or the noseto-tail method.
 Reflection (M):
o When describing a reflection, the position of the
mirror line is essential.
 Rotation (R):
o To describe a rotation, the centre of rotation, the
angle of rotation and direction of rotation are required.
o A clockwise rotation is negative and an anticlockwise
rotation is positive.
 Translation (T):
o When describing a translation it is necessary
to give the translation vector
PAGE 8 OF 10
CIE IGCSE MATHEMATICS//0580
 Enlargement (E):
o To describe an enlargement, state the scale factor, K
and the centre of enlargement
  =
ℎ  
ℎ  
2
   =    
o If K > 0, both object and image lie on same side of the
centre of enlargement.
o If K < 0, object and image lie on opposite side of the
centre of enlargement.
7.4 Transformation by Matrices
 Reflection:
1 0
o(
)
0 −1
−1 0
o(
)
0 1
0 1
o(
)
1 0
0 −1
o(
)
−1 0
 Enlargement:
 0
o(
)
0 
 Rotation:
0 −1
o(
)
1 0
0 1
o(
)
−1 0
−1 0
o(
)
0 −1
Independent events:
 Two events are independent if occurrence of one is
unaffected by occurrence of other.
 The AND Rule:
o p(A and B) = p(A) × p(B)
9. STATISTICS
Reflection in the  − 
9.1 Histograms
Reflection in the  − 
Reflection in the line  = 
Reflection in the line  = −
where k=scale factor and centre
of enlargement = (0,0)
Rotation 90° anticlockwise, centre (0,0)
Rotation 90° clockwise, centre (0,0)
Rotation 180° clockwise/
anticlockwise, centre (0,0)
8. PROBABILITY
 Probability is the study of chance, or the likelihood of an
event happening.
Probability of an event =
   
   
 If probability = 0, the event is impossible and if
probability =1, the event is certain to happen
 All probabilities lie between 0 and 1.
 A histogram displays the frequency of either continuous
or grouped discrete data in the form of bars.
 The bars are joined together.
 The bars can be of varying width.
 The frequency of the data is represented by the area of
the bar and not the height.
 When class intervals are different it is the area of the bar
which represents the frequency not the
 height
 Instead of frequency being plotted on the vertical axis,
frequency density is plotted.
 Class width = Interval
 Frequency density = Height
 =  ℎ ×  
9.2 Averages
8.1 Events
 Mean:
Exclusive events:
 Two events are exclusive if they cannot occur at the
same time.
 The OR Rule:
o For exclusive events A and B
o p(A or B) = p(A) + p(B)
  
  
 Median:
o The middle value when the data has been written in
ascending or descending order
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CIE IGCSE MATHEMATICS//0580
o
o
5+1
Odd no. of values 2 = 3 
6+1
Even no. of values 2 = 3.5ℎ 
(add two values divide by 2)
 Mode:
o Most frequently occurring value
 Range:
o Difference between highest and lowest values
 Estimated mean of grouped data:
o Work out midpoints of each group and multiply by
frequency
o Divide by number of values
9.3 Cumulative Frequency
 Cumulative frequency is the total frequency up to a
given point.
 Inter-quartile range = upper quartile − lower quartile
PAGE 10 OF 10
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