d
e
t
a
r
Integ
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e
i
Sc
Terry Hudson
& Debbie Roberts
Macmillan Education
The Campus, 4 Crinan Street, London, N1 9XW
A division of Macmillan Publishers Limited
Companies and representatives throughout the world
ISBN 978-1-380-00703-2 AER
Text © Terry Hudson & Debbie Roberts 2016
Design and illustration © Macmillan Publishers Limited 2016
The authors have asserted their right to be identified as the authors of this work in accordance with the Copyright, Designs
and Patents Act 1988.
First published 2016
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or
by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the
publishers.
Original design by Macmillan Publishers Limited
Page make-up by Sparks – www.sparkspublishing.com
Illustrated by Oxford Designers & Illustrators
Cover design and illustration by Clare Webber
These materials may contain links for third party websites. We have no control over, and are not responsible for, the contents
of such third party websites. Please use care when accessing them.
Contents
Introduction
How to Use This Book
Revision and Exam Tips
4
4
5
Section A The Organism and Its Environment
Unit 1 Matter
Unit 2 Reproduction and Growth
Unit 3 Food and Nutrition
Unit 4 Transport Systems
Unit 5 Respiration and Air Pollution
Unit 6 Excretion
Unit 7 Sense Organs and Coordination
Unit 8 Health and Sanitation
Test Questions for Section A
6
11
20
27
34
39
43
50
55
Section B The Home and Workplace
Unit 1 Temperature Control and Ventilation
Unit 2 Conservation of Energy
Unit 3 Electricity and Lighting
Unit 4 Machines and Movement
Unit 5 Metals and Non-Metals
Unit 6 Acids, Bases and Mixtures
Test Questions for Section B
56
59
63
71
75
80
85
Section C Earth’s Place in the Universe
Unit 1 The Universe and Our Solar System
Unit 2 The Terrestrial Environment
Unit 3 Water and the Aquatic Environment
Unit 4 Fossil Fuels and Alternative Sources of Energy
Unit 5 Forces
Test Questions for Section C
86
90
97
102
106
108
Paper 1 Practice Questions
109
Paper 2 Practice Questions
110
Answers to Test Yourself Questions
111
Glossary
117
Introduction
Written by experienced teachers and authors, Macmillan Education’s CSEC® Revision Guides provide
a clear route to exam success. Inside this book you’ll find complete, concise revision notes on all key
syllabus topics, in addition to practical advice on how to approach your revision and tackle the exams
themselves, helping you to prepare effectively for your examinations.
Having reviewed the key points of each topic, you can refresh your knowledge and build your
confidence with in-text practice questions, before moving on to sample practice exam papers at the end
of the book. Questions are written in CXC examination style so that you will become familiar with exam
wording and know exactly how to achieve your best possible grades.
More revision resources are available online at www.macmillan-caribbean.com.
How to Use This Book
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
Each section starts with a
concept map showing key topics
and, crucially, how they link together.
Does X cause Y? Does X run in tandem
with Y? Does X allow Y to happen?
No
Each section begins with a checklist so
you can rate your confidence in each topic
and prioritise your revision effectively.
At the end of each section you
will have the opportunity to fill in
your own blank concept map to
check your understanding. It will
also provide a useful summary for
last‑minute self‑testing.
Reviewed
Test Yourself with these quick fire questions
to monitor your progress.
Revised
Mastered
You’ll find these checkboxes for each topic so
you can track your learning and be confident
you’ve covered everything thoroughly. Review
the topic and return to your Student’s Book if
there’s anything you don’t understand, then
come back and revise the topic in this Revision
Guide – and tick ‘Mastered’ when all of your
answers were correct!
Revision Tips provide you with interesting
ways to make sure you retain all of this
information.
Whenever you find a keyword highlighted
like this, you can find out its meaning in the
glossary at the back of the book.
Remember boxes
contain handy nuggets of key information.
If you don’t understand these,
go back to your Student’s Book
and refresh the topic.
Revision and Exam Tips
The content in this revision guide has been carefully written to make sure you have all of the key
information needed for CSEC success at your fingertips. It has already been broken down for you into
manageable chunks, based on the official CXC syllabus and exam structure.
Here are some tips to help you get the best out of this material:
Start preparing ahead of the exams so you give yourself enough time to get through all your work.
■■ Set long-term and short-term goals to help break up the work into manageable chunks.
■■ Write out a revision plan to help you stay on track; make sure to include breaks as learning is much
more effective when spaced out over stretches of time.
■■ Remove all distractions from your study area.
■■ Make sure you have all the resources you need – this guide, a pen and extra paper.
■■ Use practical memory aids where you can; make flash cards, and use tables and mind maps like the
ones in this guide.
■■ Try explaining all of the key words to another person without looking at the glossary.
■■ Test yourself and ask someone to test you.
■■ Recognise your revision milestones using the self-check boxes provided.
■■
In the exam:
Spend the first 10 minutes reading through the paper carefully, and work out a rough schedule to
make sure you complete all the questions.
■■ Read each question before trying to answer it.
■■ Check your work and presentation carefully.
■■ Make sure you understand what the questions mean, so you can apply your knowledge properly:
■■ Analyse: study something in detail and identify characteristics of each piece of information
■■ Assess: make a judgement based on the facts provided
■■ Calculate: work out the value
■■ Comment: give your opinion
■■ Compare: give similarities
■■ Contrast: give differences
■■ Define: give the meaning
■■ Describe: give the characteristics
■■ Discuss: give the key points
■■ Estimate: give a value based on rough working
■■ Explain: give reasons
■■ Identify: name/characterise
■■ Illustrate: give examples
■■ Justify: support your answer with evidence
■■
The Organism and Its Environment
Section A
Unit
1
Matter
Concept Map
Plant and animal cells
Particle theory
Organelles
Cells
Prokaryotic
and
eukaryotic
Solids, liquids,
gases
MATTER
Physical
properties
Diffusion, osmosis
and active transport
Self Check
Tick the box that shows how confident you feel
I can name the three states of matter.
I can name the processes that take place
during changes of state.
I can describe how heating and cooling
cause changes of state.
I can explain the different states using
the particulate theory of matter.
I can explain how the arrangement of
particles in materials helps to explain
their properties.
6
Yes
Maybe
No
The Organism and Its Environment
Section A
Three States of Matter
Reviewed
Revised
Mastered
Anything which takes up space and has mass is known as matter. Almost all matter exists as solids,
liquids or gases. These are the three states of matter. The arrangement of particles in
solids, liquids and gases helps to explain their properties.
The Arrangement of Particles and Properties
In solids and liquids the forces between particles are strong. In gases the forces between particles are
weak and so they are free to move around. The closeness of the particles and
the forces between them explains their properties.
Remember
The state of a substance depends on how closely packed or how far
apart the particles are. When substances are heated or cooled they
can change state.
If a gas is given a great deal of energy the
particles can split into positive and negative
ions. This is known as a plasma.
This is sometimes called
the fourth state of matter.
Test Yourself: Fill in the information missing from the diagram.
Solid
Liquid
Gas
Regular shape
3
Takes the shape
of the container
1
Fixed volume
4
High density
Medium to high
density
5
2
Not easily
compressed
6
Particles held
closely together
in fixed pattern
Particles move
within the liquid
7
Test Yourself:
1. In which state are the particles able to move around freely?
2. Why are solids more difficult to compress than gases?
7
The Organism and Its Environment
Section A
Plant and Animal Cells
Reviewed
Revised
Mastered
Living things are made up of cells. Plant and animals cells have many similarities but they have some
important differences.
Test Yourself: Use the words listed below to label the plant and animal cells. Some of the labels
will need to be used for both the animal and the plant cell.
1
2
3
4
5
6
7
8
9
cell wall
cytoplasm
chloroplast
cell membrane
vacuoles
starch grain
nucleus
mitochondria
glycogen granule
Test Yourself: Complete the table. One has been done for you.
Found in
Cell organelle
Plant cells
Animal cells
Nucleus
✓
✓
Cytoplasm
Cell wall
Cell membrane
Mitochondria
Chloroplasts
Vacuoles
Starch grains
Glycogen granules
8
Section A
The Organism and Its Environment
Functions of Cell
Components
Reviewed
Revised
Mastered
The structures found inside cells are called
organelles.
Cell wall
Site where energy
is produced during
respiration
The organelles of the cell work together to keep the cell
alive. Each organelle has special functions.
Nucleus
Where most of
the cell’s chemical
reactions occur
Cell
membrane
Site where
photosynthesis
takes place
Cytoplasm
Prevents plant
cells from
bursting
Chloroplast
Contains the
genetic material
of the cell
Mitochondria
Controls
exchange of
materials
Test Yourself:
1. Link each organelle to its function. One has
been done for you.
2. Which structures are found in BOTH animal
and plant cells?
3. Which organelles in cells are responsible for
producing energy during respiration?
4. Which organelle controls the movement of
substances into and out of the cell?
Microbes
Microorganisms are very important organisms. Many of
these, such as bacteria and yeast, are made up of only a
single cell. They are unicellular. Yeasts are a type of
fungus. Some fungi, such as mushrooms, are made up of
many cells but are still classed as microorganisms.
Microorganisms have many important uses, for instance in
food production. We use yeast to make bread.
Microorganisms can also have a negative effect. Bacteria
cause diseases such as cholera, diphtheria and TB
(tuberculosis). Fungi cause diseases in plants and also
human infections such as athlete’s foot and thrush.
Viruses also cause diseases. These are much smaller than
bacteria and are made up of a small piece of genetic
material inside a protein coat. Viruses can only reproduce
inside other cells.
Reviewed
Revised
Mastered
Making yoghurt
and cheese
Recycling
of natural
materials
Antibiotics
Bacteria
Manufacture of
chemicals such as enzymes
and medicines
Nitrogen fixing
in legumes such as peas
and soya beans
Yeast in brewing
and baking
Mushrooms
to eat
Antibiotics
Fungi
Veins
in cheeses
Recycling of
natural materials
9
The Organism and Its Environment
Section A
Diffusion, Osmosis and
Active Transport
Reviewed
Revised
Mastered
Cells have to allow substances to move in and out. This happens in three main ways.
Diffusion is the movement of particles from a region
Bromine vapour
has diffused to
fill the jar
of high concentration to low concentration. The particles
move down a concentration gradient – from high to low
concentration.
Lid removed
Bromine
vapour
An important example of diffusion is gas exchange in the
alveoli. Oxygen diffuses from the lungs into blood vessels and
carbon dioxide diffuses in the opposite direction. See page 35
for more details.
Bromine
vapour
Osmosis: this is a special example of diffusion. It is the diffusion of water molecules across a partially
permeable membrane such as a cell membrane. Water moves in both directions but there is a
greater movement from high concentration to low concentration.
High solute
concentration
Low water
concentration
Low solute
concentration
High water
concentration
Test Yourself: On the diagram draw an arrow
to show the net movement of water through
the membrane.
Partially permeable
membrane – like a
cell membrane
Active transport: this is when particles are moved across cell membranes against a
concentration gradient. The cells need to use energy and the process involves carrier proteins in the
membrane.
Test Yourself:
1. Name some different types of microorganism.
2. Explain how being able to smell scent is an example of diffusion.
3. Why are osmosis and active transport essential for living things?
10
The Organism and Its Environment
Section A
Unit
2
Reproduction and Growth
Concept Map
Animals
Sexually transmitted
diseases
Purpose and importance
Sexual reproduction
REPRODUCTION AND
GROWTH
Plants
Cell division
Preventing pregnancy
Population growth
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can list differences between asexual
and sexual reproduction.
I can describe the importance of cell
division.
I can explain the advantages and
disadvantages of asexual reproduction.
I can explain the advantages and
disadvantages of sexual reproduction.
I can describe the process of
reproduction in plants and humans.
I can list some examples of sexually
transmitted diseases and methods of
prevention.
I can compare growth patterns in
selected organisms.
I can explain the need for human
population control.
11
The Organism and Its Environment
Section A
Sexual and Asexual
Reproduction
Reviewed
Revised
Mastered
Reproduction is the process by which living things make offspring.
Binary fission in amoeba
Asexual reproduction only needs one
parent. The offspring are genetically identical
copies of the parent. They are clones. Unicellular
organisms reproduce by asexual reproduction. They
do this by splitting in half through a process called
binary fission. Plants can also reproduce using
asexual reproduction.
Cell
grows
Nucleus
divides
Sexual reproduction needs two parents. Each parent produces sex cells
or gametes. Each gamete contains half of the genetic material
needed for a new organism.
■■
■■
Male gametes: pollen or sperm
Female gametes: eggs
The male and female gametes fuse
together during fertilisation and
the cell that forms has the full amount of
genetic material. This is a mixture of the
genetic material from the two parents.
Cytoplasm
splits
Two identical
offspring
Remember
Asexual reproduction only needs one
parent but does not produce unique
offspring so there are no chances for
new and improved organisms.
Reproduction
Advantages
Disadvantages
Asexual
Rapid population
increase
No genetic variation
No partner needed
Sexual
Asexual Reproduction in
Plants and Animals
Introduces variety
into a species
Reviewed
Time and energy
needed to find a mate
Revised
Mastered
Reproduction in plants is also called propagation.
Natural vegetative propagation: the plant makes use of storage or perennating
organs to remain dormant between growing seasons. Perennating means to survive from one growing
season to another. Corms, tubers, tap roots and bulbs are examples of these storage organs.
Plants can also send out roots near the surface from which new plants grow. These roots are known as
runners – such as those seen in strawberries.
Artificial vegetative propagation: farmers and gardeners use:
Cuttings: a leafy branch or cutting is taken from a plant and planted in well-aerated soil. Sometimes
plant hormones are used to encourage growth. The cutting can grow into a new plant.
■■ Budding: a dormant bud is taken from one plant and attached to another.
■■ Grafting: this is similar to budding but this time a small branch is attached to the other plant.
■■ Tissue culture: a few cells are taken from a ‘parent’ plant and grown in the laboratory until they form
a ball of cells. This ball, or callus, is treated with hormones and forms shoots and roots.
■■
12
The Organism and Its Environment
Section A
Stages of growth
Bulb
Runner
Runner
Cuttings
Asexual reproduction, or
Cuttings
cloning, is less common in
animals than in plants. Cloning
allows exact copies of a valuable
animal to be produced.
Branch cut
Plant grows
from plant
from the cutting
Branch cut
from plant
Grafting
Grafting
Plant prepared
Plant grows
from the cutting
Graft added
Plant prepared
Graft added
Graft fixed and the plant grows
Graft fixed and the plant grows
Test Yourself:
1. What is the difference between a bulb and a runner?
2. Explain the differences between a cutting and a graft.
13
The Organism and Its Environment
Section A
Sexual Reproduction in
Plants and Humans
Test Yourself: Draw arrows to show where on the
plant the petals, stamen and pistil are found and write
in their functions.
Petal function
Reviewed
Revised
Mastered
Flowers contain the male and female
reproductive organs of the plant.
Pollen must travel from the anther to a
female stigma in order for fertilisation to
happen. This is known as pollination.
Self-pollination: pollen fertilises
Stamen function
the stigma on the flower or another flower
on the same plant. This reduces the
chance of genetic variety.
Cross-pollination: pollen fertilises
Sepal
Pistil function
Receptacle
the stigma in a flower of another plant.
This allows more genetic variation. The
offspring may be better adapted to their
environment – such as growing
stronger or being resistant to disease.
The transfer of pollen grains from one place to another is called pollination.
The wind, insects and animals can spread pollen grains.
Fertilisation
Remember
Some plants have separate male
and female flowers. These are
hermaphrodite flowers.
Two male nuclei from the pollen enter the ovary. One
fertilises the ovum (female gamete) to make a zygote
and this will develop into the embryo. The other
fuses with another nucleus in the ovule to later form
the tissue that will store food.
Pollen grains
Ovary
Pollen lands on
the stigma
A pollen tube
grows down
The pollen tube
enters the ovary
via the micropyle
Test Yourself:
1. Which part of a flower produces pollen?
2. What are the ADVANTAGES of cross-pollination?
3. Explain how seeds form following fertilisation.
The outer wall of the ovule hardens to form the outer coat of the seed called the testa. The seed is the
zygote, food store and outer testa. The wall of the ovary develops into the fruit.
The human male gametes are called sperm. They are formed inside the testes. The testes hang below the
body in the scrotum to keep the temperature 2°C below body temperature. Sperm cells are mixed with a
fluid to produce semen.
14
The Organism and Its Environment
Section A
Male reproductive system
Ureter
Bladder
Seminal
vesicle
Female reproductive system
Rectum
Fallopian
tube
Prostate
gland
Uterus
Ovary
Epididymis
Penis
Testes
The human female gametes are called ova or eggs. These are produced in the ovaries. During sexual
intercourse semen is sent into the vagina and sperm cells swim to meet the egg in one of the fallopian
tubes where one sperm fertilises the egg.
The Menstrual Cycle
Revised
Mastered
The menstrual cycle is controlled by hormones and
takes place so that a female’s body is prepared for
reproduction. During menstruation many changes take
place to the uterus and ovaries.
Oestrogen
Progesterone
The egg bursting
out of the follicle
One emerges as at the moment of
“dominant” and ovulation
grows alone
Reviewed
Developing eggs
inside the follicles
The follicle left
behind turns into
the corpus luteum
(yellow body)
Uterus lining
is shed
New egg and Egg released
Uterus lining Unfertilised egg
uterus lining
thickens further passes through
begins to thicken
uterus
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
The broken down lining of the uterus, which contains blood, mucus and the unfertilised egg, passes
out of the vagina. This is known as menstrual bleeding or the period. Menopause is when the menstrual
cycle and periods stop and a woman is no longer able to become pregnant. This happens between the
ages of 45 and 55.
Test Yourself:
1. What is the purpose of the menstrual cycle?
2. What is the role of progesterone during the menstrual cycle?
3. What is the menopause?
Remember
The menstrual cycle involves ovulation,
hormone production, build-up of the uterus
lining, breast development and (if the egg is
not fertilised) menstrual bleeding. The cycle
usually takes approximately 28 days.
15
The Organism and Its Environment
Section A
Ovulation to Birth of
a Foetus
Reviewed
Revised
Mastered
Ovulation is when an ovum or egg is mature and is released from a follicle in the ovary and passes
into the fallopian tube. The ovary also releases the hormone oestrogen. Tiny hairs called cilia help
the ovum to travel along the fallopian tube. The burst follicle of the ovary turns into the corpus luteum
and later produces the hormone progesterone.
Remember
Fertilisation is when one of the millions of sperm cells that
Oestrogen starts the building of the lining
of the uterus and progesterone makes
the lining thicker and prepares the
breasts for milk production.
have swum up the fallopian tube meets the egg and penetrates the
egg’s surface. Only the head of the sperm enters the ovum and then
other sperm are prevented from entering. It is during fertilisation that
the genetic material from the male meets that of the female.
1
2
3
Sperm cells
Sperm
compete
cells
Sperm
compete
cells
Onecompete
sperm
Oneenters
sperm
One
theenters
sperm
Only
theenters
oneOnly
sperm
theoneOnly
sperm
one sperm
to enter the
to enter
ovumthe
to enter
ovumegg.
the ovum
The egg.
fertilisation
The egg.
fertilisation
The
cellfertilisation
has been
cell has been
cell has been
membrane
membrane
lifts membrane
lifts able to
liftsenter
able to enter
able to enter
The fertilised ovum is called a zygote. This starts to undergo cell division as each cell divides in two. This
continues until a ball of cells called an embryo is formed.
Hormonal levels during pregnancy
Hormonal levels
120
Oestrogen
Progesterone
100
80
60
Approximately seven days after fertilisation the embryo
becomes embedded in the lining of the uterus. After
this implantation the placenta begins to form. This
is the link between the baby and the mother that allows
the exchange of materials. Oestrogen and progesterone
continue to be produced.
40
20
0
4
6
8
10
12
14
16
Week of pregnancy
18
20
22
A membrane called the amnion surrounds the embryo
so that it develops in a fluid filled sac to protect it.
The fluid is called amniotic fluid. In here the embryo
develops into a foetus (fetus) and continues to develop
for nine months until birth.
Test Yourself:
1. Explain how the ovum moves from the ovary to the uterus.
2. What is a zygote?
3. Describe the role of oestrogen.
16
Remember
The blood of the mother and
baby do not mix at the placenta.
The Organism and Its Environment
Section A
Methods of Birth Control
Reviewed
Revised
Mastered
Birth control methods can be natural, barrier, hormonal or surgical. All involve stopping sperm reaching
the ovum inside the female.
Type of birth
control method
Natural
Example
Advantages
Disadvantages
Abstinence
100% safe and no risk of
pregnancy
No opportunity for sexual
intercourse
Rhythm method
Natural with no side effects;
approved by many religions
Can be complicated;
no protection against disease
Withdrawal
Natural with no side effects;
free
No protection against disease;
not very effective
Condom – worn by
the man
Best barrier against diseases;
cheap
Condoms can break;
some people allergic to latex
Diaphragm – used by
the woman
Easy to use; protection for up
to 6 hours
No protection against diseases;
messy as have to use spermicide;
may be allergic to latex
Intrauterine device
(IUD) – worn by the
woman
Very effective in preventing
pregnancy;
once fitted stays in place
No protection against diseases;
risk of infection after fitting
Hormonal
Oral contraceptive
(the pill) – taken by
the woman
Very effective in preventing
pregnancy;
constant protection
No protection against diseases;
need to take regularly;
some side effects
Surgical
Male tubal ligation
(vasectomy)
Very effective in preventing
pregnancy; life-long
May not be reversible;
no protection against diseases
Female tube ligation
Very effective in preventing
pregnancy
Is not reversible;
no protection against diseases
Barrier
Test Yourself:
1. Which birth control methods give the most protection against diseases?
2. Why must people be sure they do NOT want children before having a tubal ligation?
Pre- and Post-Natal Care of
Mothers and Babies
Ultrasound
transducer
Non-harmful
soundwaves
Reviewed
Revised
Mastered
Pre-natal care is especially important in the first four months
of pregnancy. Mothers visit the doctor regularly for checks. An
ultrasound may be used to check the growth of the baby.
Other tests that are carried out:
■■ The mother’s blood is checked
Remember
for Rhesus factor,
Pre-natal means ‘before birth’.
iron level and immunity to
Post-natal means ‘after birth’.
diseases such as rubella.
■■ The mother’s urine is checked
for diabetes and kidney or bladder infections.
■■ The mother’s weight is checked to see if she is eating
properly and the baby is developing well.
17
The Organism and Its Environment
Section A
Pre- and Post-Natal Care
Reviewed
Revised
Mastered
Test Yourself: Fill in the gaps in the statements. One has been done for you.
Pregnant women should:
1. Exercise regularly.
2. Eat a
diet with plenty of calc
3. Avoid dangerous substances such as
4. Warn their doctor if they need an x.
Post-natal care involves providing the baby with:
■■ Food
■■ Warmth and comfort
■■ Emotional development
■■ Protection from disease.
and v
.
.
Test Yourself:
1. How does breast milk protect babies from
diseases?
2. Describe TWO examples of pre-natal care.
Breast-feeding helps with food and protection against disease as the milk contains essential nutrients
and antibodies against diseases. Babies are also given vaccinations to protect against diphtheria,
whooping cough, tetanus, meningitis, hepatitis and polio.
STDs
Reviewed
Bacteria
Symptoms
• Burning when urinating
• Sores, bumps and rashes
• Testicle pain (men)
• Abdominal pain (women)
• Discharge
• Itching
Prevention
• Abstinence
• One regular partner
• Condoms
• Avoid contact with body
fluids
• Gonorrhoea
• Syphilis
• Chlamydia
Virus
• Genital herpes
• Hepatitis
• AIDS (HIV)
Fungi
• Candida
Treatment
Antibiotics
Antibiotics
Antibiotics
Treatment
No known cure
No known cure
Antiretroviral drugs
Treatment
Revised
Mastered
Sexually transmitted diseases (STDs) are
diseases passed on during sex.
Remember
STDs can only be caught by sexual activity.
Condoms can prevent the transmission of STDs.
You cannot catch STDs from money, books,
shaking hands, insect bites, plates, cups
and toilet seats.
Antifungals such as
fluconazole or
diflucan
Test Yourself:
1. List THREE ways that sexually transmitted diseases can be prevented.
2. How are bacterial diseases treated?
18
The Organism and Its Environment
Section A
Growth Patterns
Reviewed
Revised
Mastered
Animals and plants increase in size and weight as they grow.
Most living things grow quickly at first and then that growth
slows down or even stops. Humans grow steadily, with some
differences between males and females.
Age in
years
Height of
girls (cm)
Height of
boys (cm)
5
110
110
6
115
116
7
120
122
8
122
127
9
133
133
10
138
137
11
145
143
12
152
149
13
156
156
14
160
163
15
162
168
16
163
173
17
163
175
18
163
176
Test Yourself:
1. At what age do females increase in height at a
greater rate than males?
2. At what age do males increase their height gain over
females?
Human Population Control
Reviewed
Revised
Mastered
If the number of individuals born in
Revision Tip: Population increase = Birth rate – Death rate
a population is greater than the
number dying, then the population
increases. The human population is increasing so quickly it is being called a population explosion.
Increasing populations need more space, raw materials,
energy, clean water and food. This causes problems in human
populations due to:
■■ Overcrowding
■■ Competition for resources such as food and water
■■ More children to look after
■■ More pollution
■■ Lack of employment leading to poverty and crime.
Human population growth
2048: 9 bn
2024:
8 bn
Population of the Earth
(Number of people living worldwide
since 1700 in billions)
1804:
1 bn
1700
1800
1999:
6 bn
1960:
3 bn
2012:
7 bn
1987: 5 bn
1974:
4 bn
1927: 2 bn
1900
2000
Test Yourself:
1. Try to work out how many people lived on Earth when your grandparents were born.
2. Which factors increase the birth rate of humans?
3. Why does overcrowding lead to problems in communities?
19
The Organism and Its Environment
Section A
Unit
3
Food and Nutrition
Concept Map
Equation
Factors increasing
photosynthesis
Cultivation methods
Photosynthesis
Crop production
Digestion
Importance of food
Food groups
FOOD
AND NUTRITION
Food chains and webs
Microorganisms
Nutrients
Trophic levels
Preserving food
Self Check
Tick the box that shows how confident you feel
I can describe the process of
photosynthesis.
I can describe methods of crop
production.
I can explain food chains and food webs.
I can define food groups and give
examples.
I can describe methods of preserving
foods.
I can explain the roles of different teeth.
20
Yes
Maybe
No
The Organism and Its Environment
Section A
Photosynthesis
Reviewed
Revised
Mastered
Photosynthesis is the synthesis (or making of ) glucose from carbon dioxide and water using
light energy absorbed by chlorophyll.
Sun’s energy
Carbon
dioxide
Water
Chlorophyll
Glucose
Remember
Chlorophyll is found in the
chloroplasts in plant cells found
in leaves.
Oxygen
Light energy is converted into chemical energy. The glucose made is stored as starch in the plant.
Carbon dioxide enters leaves through small holes called stomata. Water and minerals are absorbed through
the roots.
Factors that increase the rate of photosynthesis are: light intensity, carbon dioxide level and temperature.
Graphs Showing
Factors Increasing Photosynthesis
Graphs showing factors increasing
Rate of photosynthesis
Rate of photosynthesis
photosynthesis
Carbon dioxide
concentration
Rate of photosynthesis
Light intensity
Remember
Photosynthesis also takes place in algae
and in some bacteria. The bacteria do
not use the same chemical process
but they do use light energy.
Temperature
Test Yourself:
1. Name the products of photosynthesis.
2. Explain how carbon dioxide and water enter plants.
3. How does increasing the temperature affect the rate of photosynthesis?
21
Section A
The Organism and Its Environment
Crop Production
Humans grow crops to eat,
obtain raw materials and feed
animals. To make best use of
space there are a number of
ways of increasing yield and
using less water. In hilly areas
water and soil can be washed
away. Using contour ploughing,
planting and weeding can
reduce soil erosion by 50%.
Steps called terraces can also
be helpful.
Using greenhouses to control
the temperature and reduce
pests also increases crop
yields. People can grow crops
in a variety of other ways.
There are rooftop gardens,
indoor farming and plants
in containers.
Hydroponics is a way of
growing plants in liquids rather
than soil. Scientists have also
developed tissue culture to
produce many plants from
a few. You studied this on
page 12.
Test Yourself:
1. How do terracing and contouring help to preserve water?
2. List TWO advantages of growing plants in greenhouses.
22
Reviewed
Revised
Mastered
Contouring
Terracing
The Organism and Its Environment
Section A
Food Chains and Webs
Reviewed
Revised
Mastered
Food chains show feeding relationships. The chain shows energy
being passed from organism to organism.
Remember
Trophic levels
Producer
Primary
consumer
Plants are the first organisms
in food chains.
Secondary
consumer
Tertiary
consumer
One animal may eat several other plants or animals. Using a food web can show this more
complicated relationship.
Some organisms feed on dead animals and plants. These are the decomposers and they are important in
recycling materials in ecosystems.
Animals that only eat plants are herbivores. Animals that eat other animals are carnivores.
Animals that eat animals and plants are omnivores.
Test Yourself:
1. What is the name given to animals that eat plants AND other animals?
2. Why are plants called ‘producers’?
3. What would happen to the population of sharks if all of the plants in the ocean were removed?
23
The Organism and Its Environment
Section A
The Importance of Food
Reviewed
Revised
Mastered
The six food groups in the Caribbean are:
■■ staples
■■ legumes
■■ food from animals
■■ fruits
■■ vegetables
■■ oils and fats.
A balanced diet includes foods
from each of these food groups.
The foods provide the essential
nutrients the body needs.
Type of nutrient
Food sources
Functions
Carbohydrate
Cereals, sweeteners, root crops, pulses,
vegetables, fruit, dairy products
Fuel, energy storage, cell membrane, DNA,
RNA
Fat
Meat, milk, dairy products, eggs, fish oil,
vegetable seeds, nuts, vegetable oil
Fuel, energy storage, cell membrane,
hormones
Protein
Meat, fish, milk, dairy products, eggs, pulses,
cereals
Structure, transport, communication,
enzymes, protection, fuel
Water
Beverages, fruits, vegetables
Medium for biochemical reactions,
transport, thermoregulation, excretion,
lubrication
Vitamins
Fruits, vegetables, fatty fish
Energy release from macronutrients,
metabolism, bone health, blood health,
immune function, eyesight
Minerals and trace
elements
Meat, fish, milk, dairy products, salt, cereals,
fruits, vegetables, water
Mineralisation of bones and teeth, blood
oxygen transport, energy metabolism,
muscle function, maintenance of acid–base
balance and cellular fluid balance
The amount of food we eat depends on: age, gender, amount of exercise and employment. Males
require more energy each day than females and construction workers require much more energy than
an office worker.
Remember
Test Yourself:
Eating too much sugary
and fatty food can cause
1. Name TWO diseases caused by vitamin deficiency.
diabetes and obesity.
2. Which TWO food groups are rich sources of energy?
3. Which food group is needed for muscle growth?
4. Explain why a construction worker would need more energy per day than an office worker.
24
Section A
The Organism and Its Environment
Growth of Microorganisms
Many microorganisms reproduce by binary fission. They
grow and then divide in two. This means that every time
the microorganisms reproduce, the population doubles.
This is known as exponential growth.
Revised
Mastered
Exponential growth of microorganisms
The number of microorganisms
dying = number dividing
Microorganisms
doubling population
Number of cells (log)
Microorganisms need food and water just like other
living things. Different microorganisms can live in very
hot conditions or very cold conditions. Those that cause
diseases in humans often grow well at body temperature.
Reviewed
Stationary phase
Lag
phase
Death
(decline)
phase
Exponential
phase
Microorganisms
adjusting to the
new food
Food is used up
and poisons have
built up
Time
A bacterium called E. coli causes food poisoning. The number of E. coli cells growing in food can double
every 17 minutes. Over a few days a few hundred cells can result in a population of many billions.
Test Yourself:
1. Describe THREE ways of reducing the chance of microorganisms spoiling food.
2. Explain why microorganisms can be harmful if they are allowed to grow in food.
3. What is exponential growth?
Food Preservation
Reviewed
Revised
Mastered
Preserving food means stopping microorganisms from growing.
Microorganisms can grow on our food and spoil it. They
may produce toxins – which are poisons – that can make
us ill if we eat the food. Washing hands before handling
food, cooking food well, storing it in a refrigerator or
freezer and keeping it sealed are important ways to
prevent food from spoiling and being contaminated.
Test Yourself:
1. Describe THREE ways of reducing the chance of
microorganisms spoiling food.
2. Explain why microorganisms can be harmful if
they are allowed to grow in food.
Various ways of
food preservation
Bottling
and
canning
Pickling
Drying
Salting
Waxing
Vacuum
packing
Boiling
Cooling
and
freezing
Smoking
Pasteurisation
25
The Organism and Its Environment
Section A
Human Digestion
Reviewed
Revised
Mastered
Chemical
Alters the size
and shape of foods so
they can pass through
the digestive system,
e.g. teeth and
stomach
Enzymes break
down complex foods
to simple molecules,
e.g. starch
maltose
glucose
Where digestion
occurs
Product
Starch
Salivary amylase
Mouth
Maltose
Starch
Pancreatic amylase
Duodenum
Maltose
Maltose
Maltase
Small intestine
Glucose
Lactose
Lactase
Small intestine
Galactose
Proteins
Pepsin
Stomach
Peptides
Proteins
Trypsin
Duodenum
Peptides
Peptides
Peptidase
Small intestine
Amino acids
Fats and
oils
Lipase
Duodenum
Fatty acids
and glycerol
Enzymes are biological catalysts. They speed up the chemical reactions involved in breaking down food.
Each enzyme is specific – it will only speed up one reaction with one food. After being broken down the
products of digestion undergo two processes:
■■ Absorption: where materials are taken
Test Yourself:
through the wall of the small intestine. Folds
1. Explain the difference between assimilation
called villi increase the surface area of the wall.
and absorption.
■■ Assimilation: absorbed food is taken
2. How have the walls of the small intestine
into cells.
been adapted to aid absorption?
3. Describe the functions of amylase and
Undigested foods pass along the alimentary canal
lipase. Name the substrate and products in
and are sent out of the body as waste. This is called
each case.
egestion.
Human Teeth
Reviewed
Revised
Test Yourself:
1. Label the diagram using the words listed below:
canine incisors pre-molar molar
1
2. Complete the table below to show the role of each
type of tooth in digestion.
Types
2
Function
3
Used to cut off food
Used to rip and tear food
Used to grind and chew food
Used to crush and chew food
26
4
Mastered
Proteins
Physical
Enzymes
Lipids
Digestion
Nutrient
Carbohydrates
Humans digest or break down their food by a combination of physical and chemical digestion.
The Organism and Its Environment
Section A
Unit
4
Transport Systems
Concept Map
Immunisation
Blood and
blood types
Heat and
blood vessels
Drug use
Cardiovascular
diseases
Circulatory
system in
humans
Surface area to
volume ratio
TRANSPORT
SYSTEMS
Exercise
Circulatory
system in
plants
Skeleton
Vascular
bundles
Joints
Muscles
Xylem and
phloem
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can explain the need for transport
systems in living organisms.
I can name the main components of the
transport system in humans and plants.
I can identify the blood groups.
I can explain the need for
immunisation.
I can describe the problems caused by
drug use.
I can describe the structure and
function of the human skeleton.
I can explain how muscles function.
27
The Organism and Its Environment
Section A
Transport Systems
Unicellular organisms can
exchange materials with their
environment. Each cell has a
large surface area compared
with its volume. In multicellular
organisms many of the cells will
not be near the surface. Materials
have to be transported around
the organism.
Reviewed
Revised
Mastered
Centre a long way
from outer surface
Centre can be
reached by
materials
Length of side = 3
Surface area = 32 x 6 = 54
Volume = 33 = 27
Length of sides = 2
Surface area = 22 x 6 = 24
Volume = 23 = 83
Length of sides = 1
Surface area = 12 x 6 = 6
Volume = 13 = 1
Surface/volume = 2
Surface/volume = 3
Surface/volume = 6
Test Yourself:
1. Label the diagram.
2. Why do multicellular organisms need a transport system?
3. Why is surface area to volume important in cells?
Water
from the leaves.
Vessels to the
heart are called
1
2
1
2
.
3
3
4
Water
by the
4
6
Vessels from the
heart are called
6
8
28
7
5
.
5
.
The Organism and Its Environment
Section A
Structure and Function of
Transport Systems
Arteries take blood
from the heart
Veins take blood
to the heart
Reviewed
Revised
Mastered
Blood vessel
Cells NOT to scale
Left atrium
Valve
Valve
Right atrium
Valve
Valve
Right
ventricle
Left
ventricle
Plants do not have blood vessels.
Their transport system contains xylem
and phloem packed together in a
vascular bundle. Xylem tubes
transport water and dissolved substances
from the roots to the leaves. Phloem
tubes transport food and waste products
from where they are made to where they
are needed.
White blood cells
fight disease
Platelets help with
blood clotting
Plasma is the liquid
part of blood
Red blood cells carry
oxygen in haemoglobin
Test Yourself:
1. Name the FOUR chambers of the heart.
2. Which blood vessels carry blood AWAY from the heart?
3. Explain the function of red blood cells.
4. Describe TWO differences between xylem and phloem.
5. Plants do not have hearts. How does waterPhloem
move from
the roots up to the leaves?
Cells have end walls
with perforations
A cross section of a
plant stem showing
the transport system
Phloem
Phloem
A cross section of a
plant stem showing
the transport system
Remember
Phloem
Water and food
Xylem
Cells have end walls
with perforations
A vascular
Phloembundle
A cross section of a
plant stem showing
the transport system
Xylem
A vascular
bundle
Phloem
Xylem
Cambium
cells
A vascular
bundle
Cambium
cells
Water and food
Two way
Water
andflow
food
Cambium
Cells have end
cellswalls
with perforations
Xylem
Two way flow
One way flow
Two walls
way flow
Xylem tubes have thick
made of
lignin. Phloem tubes have thin
walls made from cellulose.
Xylem
One way flow
Water and minerals
No end walls
between cells
Thick walls stiffened
with lignin
Water and minerals
No end walls
Xylem
between cells
One way flow
Thick walls stiffened
with
Waterlignin
and minerals
29
The Organism and Its Environment
Section A
Blood Groups
Reviewed
Revised
Mastered
There are four types of blood group in humans: A, B, AB and O.
Group A
Group B
Group AB
Group O
Red blood cell
type
A
B
AB
O
Antibodies in
plasma
Anti-B
Anti-A
None
Anti-A and
Anti-B
Antigens in
red blood cell
A antigen
B antigen
A and B
antigens
None
If the antibody in the plasma was the same as the antigen on the
red blood cells they would stick together in clumps. This is called
agglutination. This is why it is important to match up blood
when transfusions are given.
Donor’s blood type
A
B
AB
O
Recipient’s
blood type
Blood group is determined by
the type of antigens on the
surface of the red blood cells
and the antibodies in the blood
plasma.
A
✓
✗
✗
✓
B
✗
✓
✗
✓
AB
✓
✓
✓
✓
Rhesus factor: this is a protein found in the red blood cells of some
✗
✗
✓
O ✗
people. These people are Rhesus positive (Rh+). If Rh+ blood is
given to a Rh– person then this causes agglutination. If a mother is Rh+ and her unborn baby is Rhesus
negative (Rh–) this also causes problems.
Test Yourself:
1. Which type of blood can safely be given to a person of
blood type O?
2. What is the Rhesus factor and how can it be dangerous for
unborn babies?
Cardiovascular Disease
Remember
People with blood type O can donate
blood to anyone. They are universal donors.
People with blood group AB are
universal recipients.
Reviewed
Revised
Mastered
The human heart can beat up to 3 billion times in a lifetime. However, some diseases can seriously
weaken the heart.
Cardiovascular
disease
30
Causes
Hypertension, or
high blood pressure
Caused by a hardening of the arteries so
they are not elastic. This can be the result of
age or fatty deposits of cholesterol.
Heart attack
Caused by blood vessels in the heart being
blocked. This can be due to a blood clot
that stops blood flowing. This is called a
thrombosis. This can stop the heart beating.
Stroke
Caused by a blood clot in a blood vessel
in the brain. The person affected may be
unable to speak or move and may experience
drooping on one side of the face.
Test Yourself:
1. What causes arteries to
harden and possibly cause
hypertension?
2. How can lifestyle increase
the risk of a person having a
heart attack?
Section A
The Organism and Its Environment
Immunisation
Artificial immunity is when we fool the body into thinking
we have an infection so it produces antibodies. This is done
through vaccination.
Revised
Mastered
How the body responds to infections –
natural immunity
Antibody serum
The immune system protects the body from diseases. The
microorganisms causing the disease have antigens on their
surfaces. When these unknown antigens enter the body
then antibodies are produced. These either burst the cells
or attract white blood cells (phagocytes) which engulf and
destroy the microorganisms.
Reviewed
Secondary
Primary
0
Some viruses, such as HIV (AIDS), attack the immune
system. This opens up the infected person to many
secondary diseases.
10
20
100
New pathogen
110
120
Days
Previously encountered
pathogen
Remember
Test Yourself:
1. Explain how antibodies protect the body from infections.
2. What is the primary response to infection?
3. What is a vaccine and how does it protect the body?
A vaccine contains weakened or dead disease
microorganisms. The body recognises the
antigens and produces antibodies. This prepares
the body in case a person is infected
later with the actual disease.
Drug Use
Reviewed
Revised
Mastered
A drug is a substance that affects the way the body or mind works.
Drugs can improve athletic performance and this is one reason why they are banned in sport. Drugs can
also act as stimulants or cause hallucinations. A person taking drugs can suffer from depression, heart
disease and liver failure.
Blood doping is sometimes also used illegally by athletes to help them to cheat. This is when blood is
taken from an athlete and stored. It is later added before a competition so that the athlete has more red
blood cells.
Test Yourself:
1. List THREE categories of drug.
2. Explain why blood doping enhances an athlete’s performance.
Remember
Using illegal drugs can lead to addiction.
Drug use also leads to breakdown
of families, inability to work and
increases in crime.
31
The Organism and Its Environment
Section A
The Physiological Effects
of Exercise
Reviewed
Revised
Mastered
Test Yourself: Fill in the gaps in the labels on the diagram below.
Lung capacity
.
2
.
Muscle tone im
1
3
Body mass:
Less f
.
Muscle size
C
improve.
Heart stronger.
D
improves as muscles in the abdomen
mix food better.
5
cholesterol.
The Human Skeleton
cranium = ___
clavicle = ___
scapula = ___
vertebral column = ___
humerus = ___
radius = ___
ulna = ___
pelvic girdle = ___
femur = ___
tibia = ___
fibula = ___
patella = ___
2. Name the bones of the leg.
3. Name the bones of the arm.
Exercise results in more sweating,
so you should drink more
water than usual.
Reviewed
Revised
A
Test Yourself:
1. Which bone is which? Write in the
correct letter for each bone.
4
Remember
To provide energy for exercise your body breaks down carbohydrates and fats.
This helps to balance energy input and energy output.
32
.
B
D
C
E
F
H
G
I
J
K
L
Mastered
The Organism and Its Environment
Section A
Function of the Human
Skeleton
Protection
The skeleton has many important functions. The
rigid ribs make sure the chest does not collapse onto
the lungs. This would stop us breathing. Blood
vessels are also protected by bone.
Test Yourself:
1. What are the functions of the ribs?
2. Which part of the skeleton protects the brain?
3. Explain how the skeleton helps us to
maintain our shape.
Reviewed
Revised
Mastered
Shape
For vital
organs
Holds your
body in shape
Support
Holds the vital
organs in the
correct place
Movement
Muscles and joints
allow the body
to move
Joints and Muscles
Blood
production
Red and white
blood cells are made
in bone marrow
Reviewed
Revised
Mastered
Bones are designed to be light and strong. They can flex slightly but they cannot bend. This is why
joints are needed. Some joints are fixed. They are fused together. An example is the plates of the skull.
Test Yourself:
1. Explain how a ball and socket joint works.
2. Give TWO examples of hinge joints.
Ball and socket
Hip
Hinge
Knee
Muscles are made from bundles of muscle fibres. These are like
small cables. The muscle fibres can contract and relax. This means
muscles can pull but they cannot push.
Contracted
biceps muscle
Relaxed
triceps muscle
Lower arm
moves up
Elbow joint
Slightly movable
Lumbar spine
Test Yourself:
1. Explain how the biceps and triceps muscles would work together to straighten the arm.
2. Think back to an earlier section. What effect does exercise have on muscle toning?
33
The Organism and Its Environment
Section A
Unit
5
Respiration and
Air Pollution
Concept Map
Equation
Breathing
Respiration
Respiratory
systems
Lungs
Aerobic and
anaerobic
RESPIRATION AND
AIR POLLUTION
Sources of
air pollution
Smoking
Health
problems
Self Check
Tick the box that shows how confident you feel
I can explain the mechanism of
breathing.
I can compare the composition of
inhaled and exhaled air.
I can describe the functions of
respiratory surfaces.
I can distinguish between anaerobic and
aerobic respiration.
I can explain the importance of
respiration.
I can list the causes of air pollution.
I can explain the problems caused by air
pollution.
I can explain the effects of smoking on
the respiratory system.
34
Yes
Maybe
No
The Organism and Its Environment
Section A
Breathing
Reviewed
Breathing is a mechanical process that allows air to be taken into
the body so that gases can be exchanged.
A
Inhale
B
% composition in
inhaled air
% composition in
exhaled air
Oxygen
21
16
Carbon dioxide
0.04
4
Nitrogen
78
78
Noble gases
Approximately 1
Approximately 1
Water vapour
Small amount
Larger amount
Exhale
Chest
contracts
Diaphragm
contracts
Diaphragm
relaxes
Explain.
Gases
Mastered
Chest
expands
Sternum
Ribs
Lung
Test Yourself: Does diagram A show inhalation or exhalation?
Notice that when the diaphragm moves downwards the intercostal
muscles move the rib cage upwards and out. This decreases the
internal air pressure and so air from the outside moves into the lungs.
The opposite happens during breathing out.
Revised
Y tube
(trachea and
bronchi)
Bell jar
(chest
cavity)
Balloon
(Lung)
Sheath
(diaphragm)
Volume decreases,
pressure increases
Volume increases,
pressure decreases
There is still 16% oxygen in exhaled air. That is why CPR can be effective.
Also, it is thought that the carbon dioxide being blown into a person’s lungs can trigger breathing.
Gaseous Exchange
Reviewed
Air in and out
Blood out
Blood in
Bronchiole
Capillary
Alveoli
O2
Revised
Mastered
Inside the lungs are very small air
sacs called alveoli. These increase
the surface area inside the lungs.
The alveoli are covered with a
network of small blood vessels.
This allows air in the lungs to be
brought close to the blood supply.
CO2
Remember
Gas exchange by
diffusion in lungs
Blood capillaries
Air space (alveolus)
Blood = low concentration of oxygen and high
concentration of carbon dioxide; Air = higher
concentration of oxygen and lower concentration
of carbon dioxide; Diffusion = the movement of
gases from a region of high concentration
to a region of lower concentration.
Test Yourself:
1. How does diffusion help oxygen to move from the lungs to the blood?
2. How does diffusion help carbon dioxide to move from the blood to the lungs?
3. Use your knowledge of gaseous exchange to explain the differences between inhaled and exhaled air.
35
The Organism and Its Environment
Section A
Importance of Respiration
Reviewed
Revised
Mastered
Respiration is the process of obtaining energy by the chemical breakdown of food molecules such as
glucose in cells.
Respiration takes place mainly in the mitochondria
of cells. Enzymes act as catalysts. The energy released
is used to help cells carry out functions such as growth,
repair and reproduction. Energy is also used for muscle
movement and maintaining body temperature.
Energy stored in chemicals
Glucose
Oxygen
Carbon
dioxide
Water
C6H12O6
6O6
6CO6
6H2O
If carbohydrate supplies are used up then fats and proteins can also be used as substrates. This provides
energy but can produce harmful chemicals in the blood.
Remember
Test Yourself:
1. What are the products of respiration?
2. Where does the process of respiration take place?
3. Why is energy important to living things?
Think back to photosynthesis.
The equations for respiration and
photosynthesis are opposites.
Aerobic and Anaerobic Respiration
Reviewed
Revised
The respiration described above is called aerobic respiration.
It needs a supply of oxygen. Glucose is broken down completely to carbon dioxide and water.
Mastered
If oxygen is not present then a form of respiration can still take place. This is anaerobic respiration.
Some microorganisms such as yeast can use anaerobic respiration. The glucose is not broken down fully,
so less energy is produced. During exercise muscles may not get enough oxygen. They use anaerobic
respiration to get some energy but lactic acid is made as a by-product. This causes cramp.
Test Yourself:
1. Complete the table:
Anaerobic
respiration
Glucose
breakdown
Anaerobic respiration
Yeast
Aerobic
respiration
Glucose
Needed
Muscle
Energy
Ethanol
Carbon dioxide
Not complete
Oxygen
Energy released
Small amounts
End products
Animals = lactic acid
Glucose
Energy
Lactic acid
Plants = carbon
dioxide and ethanol
2. Describe how anaerobic respiration can slow down athletes.
3. Explain how anaerobic respiration is important in brewing and baking.
4. Why is less energy obtained in anaerobic respiration than in aerobic?
36
Remember
‘Anaerobic’ simply means
‘without air’.
The Organism and Its Environment
Section A
Causes of Air Pollution
Reviewed
Revised
Mastered
The use of fossil fuels produces a great deal of air pollution.
Unburned particulate matter such as carbon, lead and diesel can be produced during incomplete
combustion. Fuels containing sulphur also produce sulphur dioxide.
Pollutant
Complete combustion –
rich supply of oxygen
Source
Carbon dioxide
Combustion of fuels
Carbon monoxide
Incomplete combustion of fuels
Sulphur dioxide
Combustion of sulphur containing fuels
Particulate matter
Unburnt carbon (soot) and fuels, dust from
building and quarrying
Lead
Used in gasoline, pipes, batteries, lead
crystal glasses and solder on cans
Methane
Animals
Emissions from the oil and gas industry
Carbon
dioxide
Fuel
Water
Incomplete combustion –
poor supply of oxygen
Carbon
monoxide
Fuel
Carbon
Water
Remember
Test Yourself:
1. How do your daily actions cause air pollution?
2. Why do vehicle engines produce carbon monoxide?
When elements burn in
oxygen they produce oxides,
monoxides or dioxides.
Problems Caused by Air Pollution
Reviewed
Acid rain caused by sulphur dioxide dissolving in water can cause
health and environmental problems. For example, plant stomata can be blocked.
Test Yourself:
1. List THREE possible causes of lung cancer.
Revised
Mastered
Bronchitis
Infection but made worse by
dust, smoke and fumes
Asthma
Lung
cancer
Triggered by
allergies to dust, smoke
and chemicals
Triggered by cigarette
smoke and pollutants
such as asbestos
and radon gas
2. Which lung infections are made worse by
smoke and dust?
3. How could blocked stomata have an
environmental impact?
Pneumonia
Infection made
worse by air
pollution
Lungs
Emphysema
Alveoli damaged by
smoking and
polluted air
37
The Organism and Its Environment
Section A
The Effects of Smoking
Reviewed
Revised
Mastered
Cigarettes contain over 4000 chemicals that might damage health. Three major ones are:
tar
nicotine
■■ carbon monoxide.
■■
■■
These are drawn deep inside the lungs.
Chemical
Description
Health impact
Tar
Oily black substance
Damages alveoli and cilia
Makes it difficult to breathe
and gas exchange is reduced
Nicotine
Addictive colourless
liquid that turns brown
Increases heart rate and
blood pressure. May cause
strokes and heart attacks
Carbon
monoxide
Colourless and
odourless gas
Bonds with haemoglobin
in red blood cells. Causes
breathlessness
Being in smoky environments can also cause health problems – even if you are not smoking yourself.
This is called second-hand smoking. That is why it is important to have smoke-free areas.
Test Yourself:
1. Describe the health problems caused by cigarette tar.
2. What health problems can be caused by second-hand smoking?
38
The Organism and Its Environment
Section A
Unit
6
Excretion
Concept Map
Evaporation
Urea
Dialysis
Sweat glands
Renal failure
Kidneys
Skin
EXCRETION
Ultrafiltration
Urea
Flowering
plants
Stomata
Nephrons
Leaf fall
and bark
Gas exchange
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can distinguish between excretion and
egestion.
I can explain the mechanism of excretion
by the skin, lungs and kidneys.
I can describe the structure and
function of the kidneys.
I can identify the waste products of
flowering plants and their methods
of excretion.
I can explain the purposes of leaf fall
and storage in bark.
39
The Organism and Its Environment
Section A
Excretion and Digestion
Reviewed
Excretion is the removal of materials from inside the body.
Egestion is the removal of undigested foods that have not been
Revised
Mastered
Remember
absorbed by the body.
The elimination of faeces
through the anus is egestion
– NOT excretion.
Excretion by the Lungs,
Skin and Kidneys
Reviewed
Revised
Mastered
Carbon
dioxide
The kidneys filter blood to remove excess water and urea. The
filtering takes place in millions of tiny tubules called nephrons.
Waste products leave the blood in the Bowman’s capsule. Only small
molecules are removed so this is called ultrafiltration.
Lungs
Water
Useful substances such as water, salts and glucose can be
Kidneys
reabsorbed as they pass down the tubes of the nephrons.
The rest passes eventually to the bladder as urine. If the
kidneys fail this is called renal failure. This allows toxins to build
up in the blood. People have to visit the hospital to have their blood
filtered through a machine. This is called dialysis.
Urea
Skin
Salts
Test Yourself: Label the diagram using the words below.
cortex medulla Bowman’s capsule glomerulus loop of Henle
2
1
3
4
5
40
The Organism and Its Environment
Section A
The kidneys also play a vital role in
osmoregulation. The process is controlled by the
hormone ADH (anti-diuretic hormone) produced in the
pituitary gland.
Body fluids
too concentrated
Excretion from the skin takes place through the sweat
glands.
More ADH
released
The evaporation of the water in sweat helps to cool
the skin. This temperature control is very important,
especially on very hot days.
Pituitary
gland
Kidneys reabsorb
more water
Remember
Urine concentration
dilute
Normal body fluid
concentration
The urea and salts that can collect on skin
are broken down by bacteria and this
irritates the skin and gives off unpleasant
smells. That is why it is important
to wash them off.
the label with the correct part of the skin.
Less ADH
released
Kidneys reabsorb
less water
Urine concentration
high
Test Yourself: Draw arrows to connect
Body fluids
too dilute
Pore
Hair shaft
Muscle
Sweat
gland
Sebaceous
gland
Blood
capillary
Hair
follicle
Fat cell
Test Yourself:
1. What is the difference between excretion and egestion?
2. Describe how the kidneys play an important role in osmoregulation.
3. Explain how excretion through the skin also helps with controlling body temperature.
41
Section A
The Organism and Its Environment
Waste Products of
Flowering Plants
Reviewed
Revised
Mastered
Like animals, plants need to excrete unwanted chemicals. Any excess carbon dioxide and oxygen is sent
out through the leaves.
The carbon dioxide is a product of aerobic respiration in plant cells.
The oxygen is a product of photosynthesis (see pages 21 and 93).
The unused gases are excreted from the plant through the stomata.
These are tiny holes in the leaves.
Remember
Plants do recycle carbon dioxide and
oxygen to some extent. Oxygen is used
in respiration and carbon dioxide is
used in photosynthesis.
Test Yourself:
1. Draw an arrow to show the movement of water out of the leaf.
2. Draw an arrow to show the movement of carbon dioxide into the leaf.
Stomata
Stomata
Waste products can also be collected in the
bark and leaves of trees. When the leaves
fall, this waste material is excreted.
Other materials are chemically altered
to make them safer and then stored in
the plant. Examples are rubber, gum and
essential oils.
42
Test Yourself:
1. What are stomata and why are they important?
2. Name the TWO waste gases excreted from
plants.
3. Explain how leaf fall helps plants to excrete
waste materials.
The Organism and Its Environment
Section A
Unit
7
Sense Organs and
Coordination
Concept Map
Voluntary and
involuntary
Nervous system
Light
Sense organs
Sight
defects
SENSE ORGANS AND
COORDINATION
Endocrine system
Hormones
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can describe the sense organs and
their functions.
I can relate the structure of the
mammalian eye and ear to their
functions.
I can distinguish between natural and
artificial light.
I can identify translucent, transparent
and opaque materials.
I can describe how to separate white
light into its component colours.
I can describe the structures and
functions of the nervous system.
I can describe the functions of the
endocrine system.
43
The Organism and Its Environment
Section A
Sense Organs and Their Functions
Reviewed
Animals detect changes in the environment using sense organs.
Revised
Mastered
Test Yourself:
Sense organ
Stimulus detected
Chemicals in the air
Chemicals in food
Touch, temperature, pain, pressure
Light
Sound and changes in position
1. Complete the table by adding the name of the sense organs.
2. List the stimuli detected by the skin.
3. Name the specialised cells that detect stimuli.
The Mammalian Eye
Reviewed
Revised
Mastered
Test Yourself: Link the parts of the eye with their specific functions.
Retina
Protection
Lens
Cornea
Pupil
Controlling
light
Iris
Optic nerve
Rods are light-sensitive cells that allow us to see black and white. Cones are light-sensitive cells that
allow us to see colour.
Test Yourself:
1. Why is it important to control the amount of
light entering the eye?
2. Describe the functions of rods and cones.
3. Explain how the lens alters shape to focus on
near and far objects.
44
Short-sighted vision:
eye unable to focus
on distant objects
Long-sighted vision:
eye unable to focus
on nearer objects
The Organism and Its Environment
Section A
Natural and Artificial Light
Light sources are either natural or artificial.
The Sun, glowing lava, lightning and glowworms are sources of natural light. Light
bulbs, candles, televisions and fireworks
are examples of artificial sources of light.
The complete spectrum of natural light,
including visible light, ultraviolet and
infrared, is ideal for plant and animal life.
Gamma
rays
10–14
Ultraviolet
rays
X-rays
10–12
10–10
10–8
Reviewed
Infrared
rays
10–6
10–4
Revised
Radar
10–2
Mastered
FM TV
Shortwave
AM
1
102
104
Wavelength (metres)
Visible light
400
500
600
700
Humans generate artificial light from energy sources. We can control this light and alter the intensity,
quantity and quality of light. The
spectrum of artificial light is not as
Test Yourself:
broad as natural light, and so it is not as
1. Explain the difference between natural and
beneficial to plant and animal life.
artificial light sources.
2. Name THREE sources of natural light.
We see colour because any light not
3. Why do colours look different under artificial light?
absorbed by an object is reflected into
our eyes. We see colours differently in
natural and artificial light, as the spectrum of artificial light is narrower.
Transparent, Translucent
and Opaque Materials
Reviewed
Revised
Mastered
Depending on how well light travels through materials we can classify them as transparent,
translucent and opaque.
■■ Transparent materials allow the most light through them. Examples are house windows, glass
bottles and car windscreens.
■■ Translucent materials allow some light through. Examples are thin paper, coloured glass and some plastics.
■■ Opaque materials do not let any light through. Examples are metals, cloth and wood.
Test Yourself:
1. Label each of the shapes shown here as transparent,
translucent or opaque.
2. Why does the cornea of the eye have to be made from
a transparent material?
3. Which would cast the darkest shadow: a transparent,
translucent or opaque material? Why?
45
The Organism and Its Environment
Section A
Components of White Light
Revision Tip: Use a mnemonic to help you to remember
the colours of the rainbow. Make a sentence with
words beginning with the first letter of the colours –
R – O – Y – G – B – I – V. Write it below:
The two most common eye defects are:
■■ Myopia (short-sightedness) –
corrected by glasses with concave
lenses
■■ Hypermetropia (longsightedness) – corrected by glasses
with convex lenses.
Cataracts are caused when the lens
becomes cloudy and so vision is impaired.
This can be the result of age, injury,
diabetes or life choices such as smoking
and heavy alcohol drinking.
46
Mastered
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Glass prism
Remember
Light is a form of energy called
electromagnetic radiation. Light travels very
fast in a straight line. The visible spectrum
of light is made of seven colours.
Reviewed
Revised
Mastered
Test Yourself: Label the diagram that shows myopia.
1
Normal eye
2
Eye with glaucoma
PRESSURE
Very bright light can damage the cells
of the retina or the optic nerve. This
is why you should never look directly
at the Sun and welders must be very
careful. Physical injury can also damage
the eyes. Eye protection during science
experiments and activities such as
cutting wood and metal is essential.
Damage to the optic nerve can result
in vision problems and blindness.
With early detection, glaucoma can
be treated.
Revised
White light
Test Yourself:
1. How are rainbows formed?
2. What are the SEVEN main colours of the visible spectrum?
3. Are black and white colours? Explain your answer.
Sight Defects
Reviewed
Build-up of aqueous
humour fluid
Damage to the
optic nerve
Test Yourself:
1. How can myopia be treated?
2. List THREE possible causes of cataracts.
3. Why is it important to have regular eye tests?
The Organism and Its Environment
Section A
The Mammalian Ear and Function
Sound waves stimulate the auditory cells of the ear. This allows us
to hear. The ear also has an important role to play in balance.
Reviewed
Revised
Mastered
Test Yourself: Label the diagram. Use the words in the list below.
2
3
4
1
5
6
7
9
8
External ear
Middle ear
Inner ear
pinna
cochlea
tympanic membrane
ossicles (stirrup/anvil/hammer)
semi-circular canals
Eustachian tube
Humans can normally hear sounds of frequencies ranging from
20 Hz to 20 000 Hz.
Remember
Loud sounds can damage hearing. Sounds
over 100 decibels can cause deafness. This
is the volume of noise made by a circular
saw or an aeroplane overhead.
Test Yourself:
1. What is the function of the tympanic membrane (ear drum)?
2. Explain how sound waves are transmitted from the auditory canal to the cochlea.
3. Which structures in the ear play a role in balance?
4. What is the function of the Eustachian tube?
47
The Organism and Its Environment
Section A
The Nervous System
Reviewed
Revised
Mastered
The nervous system transmits information from our senses around our body. The brain interprets the
stimuli and coordinates the body’s response.
Central nervous system
Voluntary actions are
Peripheral nerve system
those actions that require thought.
Involuntary actions are
reflex actions and occur quickly
and without thought.
Nerve fibres
Damage to the nervous system through injury or disease can
result in physical disabilities and even paralysis.
Test Yourself:
1. Explain the differences between voluntary and
involuntary actions.
2. Why are involuntary actions so important to us?
3. How can damage to the spinal cord cause paralysis?
48
Voluntary
Involuntary
Person sits on an
uncomfortable chair
Person sits on
a pin
Nerves send stimulus
message to the brain
Nerves send stimulus
to spinal cord
Brain interprets
the message
Nerves transmit
response from spinal cord
to leg muscles
Nerves transmit
response from brain to
leg muscles
Person jumps up
Person stands up to
find a better chair
Remember
Blinking and sneezing are
involuntary or reflex actions.
The Organism and Its Environment
Section A
The Endocrine System
Hypothalamus
Reviewed
Revised
Mastered
Pituitary gland
brain region controlling
the pituitary gland
secretes many different hormones,
some of which affect other glands
Thyroid gland
Thyroid gland
affects metabolism,
among other things
affects metabolism,
among other things
Parathyroids
Parathyroids
help regulate level
of calcium in the blood
help regulate level
of calcium in the blood
Adrenal
glands
help trigger the
fight-or-flight
response
Pancreas
regulates the level
of sugar in the
blood
Testis
Ovary
secretes female
sex hormones
secretes male
sex hormones
As well as nervous control the body has
a chemical control system. This is the
endocrine or hormonal system.
The endocrine system is a collection of
glands. These secrete (send out) specific
hormones into the blood stream.
Test Yourself:
1. What is the function of the hormone thyroxine?
2. Name TWO hormones produced by the
pituitary gland.
3. Why is the pituitary gland often called the
‘master gland’?
Hormone
Source
Role
Effect
ADH
Pituitary gland
(in brain)
Controls the water content of the
blood
Conserves body water by reducing the
loss of water in urine
Adrenaline
Adrenal glands
Prepares the body for physical
action
Increases heart rate
Insulin
Pancreas
Lowers blood glucose
Regulates carbohydrate and fat
metabolism in the body
Testosterone
Testes
Controls development of male
secondary sexual characteristics
Regulates muscle development, skin,
and penile turgor
Progesterone
Ovaries
Regulates menstrual cycle
Maintains secretory endometrium
(uterus lining)
Oestrogen
Ovaries
Controls development of female
secondary sexual characteristics
Tissue growth and cell proliferation in
specific areas in the body
FSH
Follicle stimulating
hormone
Pituitary gland
Production of eggs
Helps eggs mature in the ovaries.
Starts production of oestrogen
LH
Luteinising
hormone
Pituitary gland
Release of eggs when mature
Starts the release of the mature eggs
from the ovaries
49
The Organism and Its Environment
Section A
Unit
8
Health and Sanitation
Concept Map
Washing and
cleaning
Waste
management
Preventing
disease
Personal
hygiene
Community
hygiene
HEALTH AND
SANITATION
Control of pests
and parasites
Food
preservation
Mosquitoes
Self Check
Tick the box that shows how confident you feel
I can explain the need to practise good
personal and community hygiene.
I can explain the importance of proper
disposal of waste.
I can describe the conditions that
encourage the breeding of household
pests and parasites.
I can differentiate between pests,
parasites and pathogens.
I can identify the stages in the life cycle
of flies such as mosquitoes.
I can describe the biological, mechanical
and chemical control of pests.
I can explain the importance of food
preservation.
50
Yes
Maybe
No
The Organism and Its Environment
Section A
Personal and Community Hygiene
Reviewed
Test Yourself:
1. Which of these examples prevent the growth and
spread of microorganisms? Mark them with a large M.
2. Which of these examples prevent body odours?
Mark them with a large BO.
2
3
Revised
Mastered
Hygiene means more than keeping
clean. It includes anything we do
to stay healthy and prevent
microorganisms causing diseases. How
we wash our hands, look after animals
and dispose of waste materials are all
aspects of hygiene.
1
It is important that communities work
together to ensure good hygiene.
This includes sewage and other
waste disposal.
5
4
6
Test Yourself:
1. Why is personal hygiene so
important?
2. Why is it important that whole
communities work together to
improve hygiene standards?
Household Pests and Parasites
Pests are animals that cause us problems.
Test Yourself: Which pests cause the following
problems? Some possible pests are listed for you.
■■ Rats and mice
■■ Houseflies
■■ Cockroaches
■■ Mosquitoes
Reviewed
Revised
Mastered
Test Yourself:
1. List THREE examples of pests.
2. How do pests cause problems for
humans?
3. Explain the differences between a
parasite, a pest and a pathogen.
Bite or
sting humans
Steal
human food
Injure plants
and pets
Cause diseases
Pests
Remember
Damage clothing,
buildings and
furniture
Parasites are organisms that live on or
in another living organism and feed
on it. A pathogen is a microorganism
that causes disease.
51
The Organism and Its Environment
Section A
Life Cycle of a Mosquito
Reviewed
Revised
Mastered
Mosquitoes are parasites. They feed on the blood
of other animals, including humans. This animal
or human is called the host.
The mosquito can also carry a parasite or
pathogen from one host to another. The
mosquito is a vector. Anopheles mosquitoes
carry the malarial parasite. Aedes mosquitoes
carry the parasites that cause dengue fever
and yellow fever and the zika virus. The Culex
mosquito carries the parasite for elephantiasis.
Adult
Eggs
Adult
emerges
Mosquito
life cycle
Controlling mosquitoes involves clearing bushes
near homes, removing stagnant water, covering
water with oil, covering windows with mesh and
spraying insect repellent.
Pupa
Larva
Test Yourself:
1. Look at the list above. Group the methods into mechanical and chemical control.
2. Explain how removing water or covering it with oil reduces the numbers of mosquitoes.
Control of Pests
Reviewed
Revised
Pests can be controlled using FOUR methods: physical, biological, chemical and sanitary.
Test Yourself:
1. Which picture shows physical pest control? Give another example.
2. Which picture shows biological pest control? Give another example.
3. Which picture shows chemical pest control? Give another example.
4. Which picture shows sanitary pest control? Give another example.
1
2
4
3
52
Mastered
The Organism and Its Environment
Irradia
tion
Gamma
microo rays k
rgan ill t
ism he
Heati
ng
k li n g
nism
orga
cro grow r
Mi not
ate
can hout w
wit
food to stay fresh.
2. Describe how osmosis is used to
preserve foods.
3. Foods in cans are covered in brine
(salt water) or sugar syrup. Why
must the cans be airtight?
Mastered
microo Kills
rga
nis
m
ur
S ulp h
de
d i o x i ps
g
sto
T his o mi n ps
b e c sto
d
fruits
e an ms
t o o ri p r g a nis g
n
m icr oo g ro wi
from
Test Yourself:
1. Explain how refrigeration can help
so
ure is
erat s the
p
em top
e t it s nism
Th low roorga
g
c
mi rowin
g
ation
iger
r
f
Re
Revised
yiing
Dr
Microorganisms can contaminate food if
it is left uncovered or handled by people
who have not washed their hands. The
microorganisms can grow in the food and
spoil it. They can make us ill if we swallow
them or they can produce poisons called
toxins that also make us ill.
Reviewed
th T h e
e m ac
icr id s t o
gro o or g a n p s
is m
w in
g
Food Preservation
P ic
Section A
Bacteria
Ad
g
din g
su g
S a lti n
a
r
c Th
r is
su o n ce e h i g h
Wate from is.
fro gar ntrat
s
ed
or m fo r e m o i o n of
r e m o v o s m o is m
ga od
ves w
y
n
b
n is . T h
at
fo o d oo r g a
ms
e m ic e r
r
c
ow
i
r
m
roca n n
The
ot g
ot gro w
cann
Types of Waste
Reviewed
Revised
Mastered
Domestic waste can include
plastic and metal containers
and uneaten food. Any
uncovered food waste can
attract pests such as flies
that will spread diseases.
Industrial and chemical
waste can contain very
harmful chemicals such as
oils, acids and toxic metals
such as lead.
Biological waste such as animal and human
sewage can spread diseases and pollute rivers,
lakes and the oceans.
Electronic waste includes unwanted refrigerators,
microwaves, phones and computers. These may
contain harmful chemicals such as the toxic
metals lead and mercury.
Test Yourself:
1. List THREE examples of electronic waste.
2. Explain how electronic waste can be harmful.
3. How can food waste contribute to the spread
of diseases?
53
The Organism and Its Environment
Section A
Solid Waste and the Environment
Reviewed
Revised
Mastered
To handle waste we can just
throw it away. It can end up on
unused land, it can be buried
or it can be burned. This type of
disposal looks ugly and causes
air and water pollution as well
as attracting pests such as rats.
Animal and human faeces
can carry pathogenic
microorganisms. Diseases such
as cholera can be spread in
this way.
A more responsible approach to waste management is to: Reduce, Reuse and Recycle.
We can use the biogas produced by waste as a source of energy. We can also use biodegradable
materials rather than non-biodegradable materials.
Animals put faeces
into the water
Faecal waste
from the farm
Test Yourself:
1. What problems can be caused by throwing away waste?
2. Give an example of a waste material that can be recycled.
3. What are the advantages of using biodegradable materials?
54
Polluted river, lake
or sea
The Organism and Its Environment
Section A
Test Questions for Section A
1. Energy for cell activities is produced in the:
(a) vacuole
(b) cell membrane
(c) nucleus
(d) mitochondria
2.
A
The structure labelled A is the:
(a) vacuole
(b) mitochondria
(c) cell wall
(d) chloroplast
3. The products of respiration are:
(i) carbon dioxide
(ii) water
(iii) oxygen
(a) i and ii only
(b) i and iii only
(c) ii and iii only
(d) i, ii and iii
4. Mosquitoes lay eggs that hatch into:
(a) pupa
(b) maggots
(c) larva
(d) chrysalis
C
5. State the names of the types of joints labelled A and B.
(a) A:
(b) B:
B
(2 marks)
6. State the names of the types of joints labelled C and D.
(a) C:
(b) D:
(c) State two functions of the skeletal system.
(2 marks)
A
Function 1:
Function 2:
D
(2 marks)
55
The Home and Workplace
Section B
Unit
1
Temperature Control and
Ventilation
Concept Map
Displacement ventilation:
the movement of air
Ventilation
Mixing ventilation
mixes fresh air
The effects of
relative humidity on
bodily functions
Conduction materials
Cooling effect
of evaporation
TEMPERATURE
CONTROL AND
VENTILATION
Methods of heat
transfer
Latent heat of
vaporisation
Features
Digital
Liquid crystal
How they work
Convection through gases
and liquids
Radiation as a wave
through a vacuum
Explain how convection
currents are responsible for
land and sea breezes
Convection
currents
Thermometers
Types
Explain how they work
Household
thermostats
Infrared
Bimetallic strips
Self Check
Tick the box that shows how confident you feel
I can describe the methods of heat
transfer and their applications.
I can explain how convection currents
create land and sea breezes.
I can explain how household
thermostats work.
I can describe the features of
thermometers and how they work.
I can explain the cooling effects of
evaporation and how this affects bodily
functions.
I can explain the effects of relative
humidity on bodily functions.
I know what ventilation is.
I can explain the need for
proper ventilation.
56
Yes
Maybe
No
The Home and Workplace
Section B
Methods of
Heat Transfer
Reviewed
Heat is energy that is transferred from a body of high temperature to a body
of low temperature.
Revised
Mastered
Remember
Materials that transfer energy
are called conductors.
There are three methods of heat transfer, listed at the top of the table below:
Method of heat
transfer
Conduction
Solid Solid
Convection
LiquidLiquid
Gas
Radiation
Gas
No medium/particles
needed
Medium/Particle
Mechanism
Experiments
They knock into
surrounding particles
causing them to vibrate.
This continues until all the
particles have gained heat
energy.
When liquids and gases are
heated they expand. As particles
gain energy they move further
apart from each other.
Heating metal rods
Permanganate crystals in water
All matter radiates and
absorbs heat. If an object
radiates more than it
absorbs, it cools.
Dark, dull surfaces absorb
radiation. White, shiny
surfaces reflect radiation
away.
Thermostatically Controlled
Appliances
Coloured materials wrapped
around thermometers and
placed in the Sun
Reviewed
Revised
Mastered
Thermostats control the temperature of household appliances. Examples of appliances are irons,
refrigerators, ovens, water heaters and air conditioners.
The temperature setting knob adjusts the
temperature with the use of a bimetallic strip. The
strip is made of two metals which expand and contract
differently with temperature. This results in the strip
bending and the contacts separating, breaking the circuit.
Cooling Effects of
Evaporation
Test Yourself: Name the metals
commonly used in bimetallic strips.
Reviewed
Revised
Mastered
Sweat cools the body as it evaporates. Heat energy from the body changes the liquid sweat to a
gas or water vapour. This is known as vaporisation. The heat energy needed for a change of state is latent
heat. The heat energy supplied is called the latent heat of vaporisation. The rate that sweat cools the
body is dependent on the temperature of the skin and the amount of moisture in the air next to the skin.
Air can hold only a specific amount of moisture, so if the air is already moist, the sweat will not evaporate.
57
The Home and Workplace
Section B
Thermometers
Reviewed
Revised
Mastered
Different types of thermometer are used to measure temperature. Liquid in glass thermometers work
using the thermal expansion of liquids.
Type of thermometer
Uses
Notes
Liquid in glass –
laboratory
Temperature of gases or
liquids
Range usually of −10°C to 110°C
Scale read in situ as the liquid reacts when moved
Liquid in glass – clinical
thermometer
Temperature of the
human body
Placed under the arm or tongue
Cannot be read in situ
A bend in the tube prevents the mercury falling when it is moved
Liquid in glass –
maximum–minimum
thermometer
Measures the highest and
lowest temperature over
time
Has u-shaped tube
A steel index stays in place when the liquid expands or contracts
Digital thermometer
Body temperature.
Applying to the ear gives
a temperature reading as
an alternative to clinical
thermometers
Uses an electrical sensor and a microchip that converts the electrical
signals to a numerical display
Liquid crystal
Surface temperature
Plastic strips can be placed on the surface of objects, for example the
forehead or fish tanks
Infrared
Temperature of any object
Does not need contact with an object – detects infrared radiation
from an object. This is converted into a digital temperature reading
Ventilation
Reviewed
Revised
Mastered
Ventilation allows air to circulate in an enclosed space, replenishing oxygen and removing stale air,
carbon dioxide, excess heat, dust, odours and microorganisms, and helps to control pollutants and humidity.
Mixing ventilation
Fans or natural breezes are mixed with stale air.
Displacement ventilation
Air is mechanically moved through outlet vents, allowing rising hot
air to move out of the space.
or dilution ventilation
or mechanical ventilation
Vents facing the wind improve ventilation. Cross-flow can be achieved if vents are facing each other.
Air Conditioners and Humidifiers
1
58
Heat XFER
to air
Condenser
Evaporator
Heat XFER to
refrigerant
Cool refrigerant
Hot refrigerant
Humidifiers regulate the amount
Compressor
of moisture in the air (humidity),
4
2
which affects evaporation. If the
air is too humid it encourages
Cool air
Warm air
Ambient
Ambient
Fan Fan
the growth of bacteria and can
to inside
to outside
air
air
have a negative impact on health.
3
A humidifier helps to relieve
Expansion valve
allergies and other respiratory
Cold refrigerant
Warm refrigerant
ailments. It can also help to
Condensation drains to outside
alleviate itchy eyes, dry skin
and cracked lips caused by low humidity. Cool mist evaporative humidifiers use a filter that acts as a wick,
absorbing water from a reservoir. An electric fan then blows air across the filter. This evaporates the water
and blows the moistened air into the room.
The Home and Workplace
Section B
Unit
2
Conservation of Energy
Concept Map
Energy as an
ability to produce
charge
Concept
and unit of
energy
Wave method
The
interconversion
and conservation
of mass energy
Transport
and the transfer
of energy
CONSERVATION
OF ENERGY
Energy reflected and
brought to focus
Vehicular collisions
Energy can be
interconverted,
stored, put into
motion or used
to do work
Principles
of momentum
conservation
Formula P = M x V
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can explain the concept of energy.
I know the unit of energy.
I can discuss the inter-conversion and
conservation of mass and energy.
I can describe the methods used in
transferring energy.
I can explain the principle of
conservation of momentum.
59
Section B
The Home and Workplace
Concept and Unit of Energy
Reviewed
Revised
Mastered
Energy is the ability to do work, or, we can think that energy makes things happen.
Energy is used when we walk or switch on an electric light.
■■ There are many forms of energy.
■■
■■
Test Yourself: Give examples for each of the following forms of energy.
1. Kinetic energy (KE) is the energy of motion or movement energy. It can also appear
as heat and sound.
Example:
2. Electrical energy is often called electricity. Negatively charged electrons carry
electrical energy.
Example:
3. Light energy is mainly from the Sun and from luminous objects. It is important for life as
it is needed for photosynthesis.
Example:
4. Solar energy comes directly from the Sun, mainly in the form of heat and light.
Example:
5. Sound energy is carried through materials by vibrating molecules.
Example:
6. Chemical energy is energy stored in chemical structures, for example food. It is a form
of potential energy.
Example:
7. Heat energy moves from a hotter object to a cooler object. The molecules of hotter
objects pass on kinetic energy to cooler molecules that increase the temperature of the object.
Example:
8. Nuclear energy is stored in the nuclei of atoms that can be released in nuclear reactions.
It is another form of potential energy.
Example:
9. Potential energy (PE) is the energy stored in an object that has the potential to
change.
Example:
Remember
The unit of measurement
for energy is the joule (J).
60
The Home and Workplace
Section B
Reviewed
Inter-Conversion and
Conservation of Mass Energy
Revised
Mastered
Energy can neither be created nor destroyed, but is
converted from one form to another.
A TV uses electrical energy and converts it to sound and
light energy. Heat and kinetic energy are also converted
from the electrical energy and are lost to the surroundings.
The swinging of a pendulum demonstrates the interconversion of potential energy (when the pendulum
is at the top) to kinetic energy as it drops down.
Light
Chemical
Electrical
Thermal
Chemical
Mechanical
Chemical
Mechanical
When we run we demonstrate an inter-conversion of stored chemical
energy.
Remember
E = mc2 E = energy, m = mass and
c = the speed of light in a vacuum.
Test Yourself:
1. Name the process that converts energy from the sun to food.
2. Think about TWO further examples of energy conversions.
What does this tell us about energy?
Energy and mass can be inter-converted. Energy can be
converted to mass and mass can be converted to energy. The
total amount of mass and energy in a system is always conserved.
Remember
In nuclear fission the nucleus of an atom is
split into two, releasing energy.
This energy can be used in nuclear reactors to
generate steam, which turns turbines
to generate electricity.
Transfer of Energy
Reviewed
Revised
Mastered
Electromagnetic radiation is the only energy transfer that does not need a material. It includes light, heat
radiation and infrared and ultraviolet radiation. These can pass through a vacuum as electromagnetic
waves. This explains how the ultraviolet rays from the Sun can pass through space.
Think about how a wave moves. Ripple tanks show the action of a wave. You might have used a slinky to
demonstrate wave movement. The wave travels from a source and carries energy as it goes.
Test Yourself:
1. How do we change the reflection and focus of light in a torch?
2. List the steps from the television signals from a satellite to your TV.
Remember
Waves can be reflected or focused,
which changes the direction or
path of the wave.
Waves in water carry energy in a similar way. Energy is absorbed by the water from wind, creating waves.
The waves can cause severe damage when the energy is converted to an object or building in its way.
61
The Home and Workplace
Section B
The Principles of
Momentum Conservation
Reviewed
Revised
Mastered
‘Momentum’ describes objects in motion. It is the measure of the state of movement of an object.
The Law of the Conservation of Momentum
When two or more objects collide, the total momentum before the
collision is equal to the total momentum after the collision, provided
that no external forces (such as friction) were acting on them.
Remember
To summarise the Law of the
conservation of momentum:
momentum before = momentum after.
We can use the following equation to describe momentum:
P=M×V
Momentum (kg m/s) = mass (kg) × velocity (m/s)
The greater the mass of an object and the greater its velocity, the more momentum the object has.
Worked Examples
1. A train has a mass of 30 tonnes and is travelling with a velocity of 15 m/s. Calculate the
momentum of the train using the formula p = m × v.
p = (30 × 1000) kg × 15 m/s = 450 000 kg m/s.
■■
Remember to convert all the figures into the correct units. (A tonne is 1000 kg.)
2. Two balls are rolled at each other. After the collision they travel off together in the same
direction. Calculate the velocity after they have collided. One ball has a mass of 8 kg
and a velocity of 4 m/s. The other ball has a mass of 2 kg and a velocity of –5 m/s (it is
travelling in the opposite direction).
Total momentum before the collision:
= (8 × 4) + (2 × –5) = 32 kg m/s + –10 kg m/s = 22 kg m/s
Total momentum after the collision:
= (2 + 8) × v = 10v kg m/s
Total momentum before = total momentum after:
22 kgm/s = 10v kg m/s
22/10 = v = 2.2 m/s
Remember
Velocity is the distance travelled in
a given time (just like speed), but
velocity also has direction.
62
The Home and Workplace
Section B
Electricity and Lighting
Unit
3
Concept Map
Insulating
connectors
Hazards caused by careless handling of appliances
Radiation
Gloves
Hazards:
First aid hazards
and fires
Voltage
Goggles
Conductors
Evaluate protective gear/wear
Masks
Helmets
Electrical
Chest masks
Chemical
Electric shock
Bush fires
Resuscitation
Amps
ELECTRICITY
AND
LIGHTING
Fluorescent
Use the
formula
V = IR
Amperage
LED
Compare
bulbs
Filament
Energy wastage
Meter rentals
Fuel adjustment charges
Ammeter
Volts
Cell
Ohms
Lamps
Use electrical
symbols
Resistors
Calculate for fuses
and flexes
Shadow formation & brightness
LED, LCD and plasma
Good
Define
conductors as … Semi-good
Electricity is measured in watts
Extinguishing
fires
Faulty equipment
Rubber
Poor
First aid
Burns
Plastic
Switch
Transformer
Voltmeter
I = W/V or 1 = P/V
Energy
conservation
Unit = 1 Kwh
Calculate electricity bills
Energy consumption:
Calculate the energy
consumption ofo
appliances
Fuse
Fuses:
Explain how a
fuse works
Wire a plug
Dangers of overloading a wire
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can discuss good and poor conductors
of electricity.
I can explain the relationship between
voltage, current and resistance
using V = IR.
I can explain how a fuse works and
calculate the amperage using I = W/V.
I can calculate energy consumption of
appliances and electricity bills.
I can discuss energy conservation.
I can compare the use of different bulbs.
I can evaluate first aid methods and
protective clothing.
I understand how to safely handle
appliances.
I can discuss the various methods used
in extinguishing fires.
63
The Home and Workplace
Section B
Conductors
Reviewed
Revised
Mastered
When negatively charged electrons flow through a material we call this an electric current.
Materials that have free electrons are good conductors as the electrons can flow easily.
Insulators do NOT allow the electrical current to flow through them easily. They are poor conductors. Some
materials are good conductors and electrons flow through them freely; others are semi-conductors.
Battery
You will probably have investigated conductors and insulators
using a circuit like the one in the diagram.
Test Yourself:
1. Think about THREE materials that you found to be good
Light
bulb
conductors and THREE that were insulators.
2. Why are sockets, wires and connections covered in
plastic or rubber?
Material
tested
Crocodile clip or connector
V = IR
Reviewed
This formula can be used to find unknown units of electricity because they
are all related in circuits.
■■ V = voltage, the force that pushes the electrons around the circuit.
It is measured by a voltmeter in units of volts (V).
■■ I = current and is the flow of electrical charge around a circuit. It is
measured by an ammeter in units of amperes or amps (A).
■■ R = resistance, which is anything in a circuit that slows down
the flow. It is calculated using the formula above and is measured in
ohms (Ω).
Watts are the unit of power or a measure of work done over time.
Test Yourself: Match the symbol to the word.
ammeter
transformer
switch
fuse
voltmeter
lamp
resistor
cell
Remember
If you rearrange the formula,
you can calculate the
resistance in a circuit.
64
Revised
Mastered
Remember
The symbol C
does NOT mean current.
Test Yourself: If the
voltmeter reads 6 V and the
ammeter reads 1.5 A, what is
the resistance in the circuit?
The Home and Workplace
Section B
Fuses Work as
Safety Devices
Reviewed
Revised
Mastered
A fuse acts as a safety device in electrical appliances. The fuse contains a wire that melts if a surge or
high current flows through it. This breaks the circuit and isolates the appliance, preventing electric shock.
Wires and sockets have an insulating coating. If a high current passes through the wires, they overheat.
This can melt the insulation, which can cause electrical fires. There are different fuses for different
appliances that allow just the right amount of power through them.
Test Yourself:
1. Colour and label the earth, neutral
Test Yourself: What would
and live wires in the picture, using
the correct colour coding.
2. Label the fuse and outer insulation.
happen if the wrong fuse
were put in a circuit?
Calculating the Amperage
for Fuses and Flexes
Reviewed
Revised
Mastered
To make sure the correct fuse is fitted in appliances and electrical devices, we need to calculate the
amperage for them.
Use the formula: I = W/V or I = P/V or P = V × I
P = Power, V = Voltage and I = Current
So P = V × I
Remember
To work out the fuse needed you
first calculate the current that
the appliance will need.
Normally fuses have the following fixed ratings: 3 A, 5 A, 13 A and 20 A.
Test Yourself: Why will the
fuse be rated slightly higher
than the current it needs?
Worked Example: A games console has a power rating
of 400 W and uses 230 V mains supply. What rating of fuse
should be used in the plug?
Current = power ÷ voltage
400 ÷ 230 = 1.74 A
The fuse rated just above 1.74 is 3 A.
Thicker wires in overhead cables and for big appliances reduce the resistance, preventing overheating
and electrical fires.
65
The Home and Workplace
Section B
Energy Calculations
Reviewed
Revised
Mastered
Electrical components transfer electrical energy to other forms of energy. The rate that the energy is
transferred determines the power of the component.
Power can be measured in:
■■ joules per second (remember it is the rate of energy transfer) (J/s)
■■ watts, where 1 W is the transfer of 1 joule of energy per second (W)
■■ kilowatts, which is the equivalent of 1000 W (kW).
Test Yourself: What is a kilowatt hour (kWh)?
The amount of power used depends on the power
rating of the appliance (kWh) and the time it is being
used for (h).
Remember
The power of appliances is measured
in watts or kilowatts.
Worked Example: What would the power
rating be for the following appliance? An
oven uses 2 kW energy in the space of 1.5 hours.
Power rating = Energy ÷ Time
2 ÷ 1.5 = 1.3 kW
Electricity Bills
Reviewed
Revised
Mastered
It is expensive to generate electricity and so we have to pay for the amount that we use. This is measured
using a meter. We even have to pay to use the meter. The meter measures how much electricity has
been used. The previous reading is subtracted from the current reading, which leaves the amount used.
Electricity companies charge fixed rates and fuel adjustment fees in addition to the cost per unit of
electricity used.
Test Yourself: Do you know the difference between flat rate and block rate?
You can calculate how much it costs to use appliances using the following formula:
Total cost = Number of kWh used × cost per unit
Worked Example: A computer has a power rating of 400 W and is used for 3 hours. The
electricity company charges a flat rate of $0.024/kWh. Calculate the cost of running the computer.
First find the energy used: 0.4 kWh × 3 hours = 1.2 kWh
Then calculate the cost: 1.2 × $0.024 = $0.0288
Test Yourself: Calculate the cost of using a ceiling fan with a power rating of 75 W that is used
continuously for 3 days.
66
The Home and Workplace
Section B
Energy Conservation
Measures
Reviewed
Revised
Mastered
Test Yourself: Do you recall how electricity is generated? Label the diagram below.
2
3
4
boiler
steam
turbine
1
generator
Heat
When fossil fuels are burned, pollutants are released into the atmosphere.
These pollutants damage the environment and are contributors to climate change. Even though we
know this, we still waste electricity.
Test Yourself:
1. Why do we call them ‘fossil fuels’?
2. List the pollutants formed from the combustion of fossil fuels.
Faulty appliances also waste energy. Electrical components should be checked regularly to ensure they
are working efficiently.
A normal computer monitor uses approximately 80 watts of electricity in an hour. A liquid crystal display
(LCD) monitor uses less than half that amount, approximately 35 watts per hour.
Electrical component
Advantages
Disadvantages
Light-emitting diode (LED)
67 W power rating
Initial expense
80% less expensive
Not always compatible
Quality of light not as good
Liquid crystal display (LCD)
Plasma
35 W power rating
Limited brightness
Improved colour
Limited viewing angle
136 W power rating
Generates heat that is wasted
Wide viewing angle
Artwork retention
Fast response
67
The Home and Workplace
Section B
Different Bulbs
Reviewed
Revised
Mastered
Artificial light is essential for our daily life. Lighting uses approximately 5% of energy consumed in an
average household.
Test Yourself: Label the filament bulb using the words to help you.
tungsten filament
Light bulb
1
2
bulb
inert gas
3
6
support wires
glass mount
5
electrical foot contact
4
This type of bulb works by heating up the tungsten filament to over 2500 °C when it is connected to
a power supply. The filament glows white hot as it heats up, emitting light. The metals evaporate and
condense on the inside of the bulb. This darkens the bulb and reduces the light emitted.
When an electrical current flows to the electrodes, electrons are forced into the mercury vapour. This
emits a blue light and ultraviolet radiation. When it reacts with the phosphor powder we can see light.
Not as much heat is emitted and so it is more economical.
An energy-saving light bulb does not rely on heat to emit light. Therefore they are more economical, but
the light produced is often less efficient.
Visible light
Phosphor
coating Mercury Ultraviolet
radiation
Base
68
Argon gas
and mercury
vapour
Mercury
atoms
Visible light
Electron
Cathode
flow
Glass
tube
The Home and Workplace
Section B
First Aid Methods
If you think someone has suffered an electric shock,
follow these rules:
Reviewed
Revised
1
2
3
4
5
6
Mastered
1. Don’t touch the person or you could also get a shock.
2. Remove the person from the source of the shock. The
easiest way is to turn off the electricity supply.
3. Check if the person is conscious. If they are:
■■
Dial for an ambulance
■■
Monitor their breathing.
4. If the person is unconscious:
■■
Dial for an ambulance
■■
Check if they are breathing
■■
If not, you may need to administer CPR, but only
if you are sure you will not get a shock from
touching them.
Extinguishing Fires
Reviewed
Revised
Mastered
The first step is to switch off the electricity supply at the mains. Use a dry or carbon dioxide fire
extinguisher to fight an electrical fire. Avoid conducting electricity into you.
Chemical fires often produce toxins. These fires should be left to the professionals, as it is difficult
to contain toxins in the air, water or surroundings. Water jet or foam
extinguishers can be used on these fires.
Remember
Bushfires are difficult to contain. Extinguishers work by removing the
oxygen from a fire, but out in the open this is difficult. Firefighters try to
remove the fuel instead by cutting a fire break.
Electrical fires cannot be
extinguished with water.
Test Yourself: Why do firefighters attending electrical fires wear rubber-soled boots?
69
The Home and Workplace
Section B
Hazards and Electricity
Reviewed
Revised
Mastered
About 60% of our body is made from water with salts dissolved into it. Water is a really good conductor
of electricity and salt water is even better. This means WE are really good
conductors of electricity and need to take care around it.
Remember
The main hazards of using electricity incorrectly are electric shock and
Water is a really good conductor
of electricity.
burns. These can be avoided by remembering these guidelines:
■■ Never touch frayed or damaged electrical cables. If the insulation is
not intact, the electrical flow can pass into you. Long cables can also
overheat.
■■ If too much electricity flows through a wire, it heats up. This can cause the insulating material to heat
up and catch fire.
■■ Damaged components should never be touched as they can conduct electricity into you. Avoid
touching anything that looks damaged. Never attempt to carry out a repair yourself.
■■ Have appliances checked regularly by experts to avoid damage to any part of the components.
■■ Avoid wiring plugs as this should only be done by an expert. Modern plugs are usually sealed to
prevent people trying to rewire or fix electrical problems.
■■ Never allow water or wet objects to enter plug sockets or touch frayed cables or broken parts of
an appliance.
Test Yourself: Why should you stop people from pushing metal objects into plug sockets?
Protective Gear
Reviewed
Revised
Mastered
People who work with electricity need to wear gear to protect themselves from electric shock.
Rubber-soled boots prevent conduction through the feet. This is important if there is water or wet foam
in contact with electricity.
Test Yourself: Look at the picture of this worker.
Helmet
1. What would each of the pieces of gear protect the
worker from?
2. Consider any advantages and disadvantages to
wearing this gear.
70
Gloves
Work
boots
The Home and Workplace
Section B
Unit
4
Machines and Movement
Concept Map
Different types
of levers
Simple machines
MACHINES AND
MOVEMENT
Inefficiencies
of machines
Energy
conversion
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can compare the different types of
levers.
I can explain the functions of simple
machines.
I can discuss the principle of mechanical
advantage and energy conversions.
I can discuss factors that contribute to
the inefficiencies of machines and the
ways of overcoming their influences.
71
The Home and Workplace
Section B
Different Types of Levers
Reviewed
Revised
Mastered
A lever is the simplest type of machine and consists of a rigid pole and a fulcrum.
The load is the object that is being moved. The effort is the force that is applied in order to move
the load. The fulcrum is the point where
the load is pivoted. Therefore the fulcrum
is often known as the pivot. Levers act as
Test Yourself: Explain the term ‘force multipliers’.
force multipliers.
There are three types or classes of lever. The class is determined by the relative position of the load, force
and fulcrum.
1
Force
Class 1 Levers
Revaluation
Load
The class 1 lever has the load and effort on opposite sides of the fulcrum.
Devaluation
Fulcrum
Test Yourself: Name TWO examples of a class 1 lever.
Effort
2
Load
Class 2 Levers
The class 2 lever has the force and the load on the same side
of the fulcrum.
Test Yourself: Name TWO examples of a class 2 lever.
Class 3 Levers
The force and load are on the same side of the fulcrum.
The force is much closer to the fulcrum than the load. This
means that more force is put in but less is applied to the
load. They are more useful for picking up small or delicate items as less
force is applied to the load.
Fulcrum
3
Class 1 and 2 levers allow you to move a larger load with little force
or effort. This means they provide mechanical advantage or
act as a force multiplier. If you look at the diagrams you might
notice that the distance moved using a lever is greater – you have to push the
lever down further to move the load up less. This can be calculated using the
velocity ratio.
Class 3 levers do NOT act as a force multiplier and have little mechanical
advantage. This makes them less common.
72
Load
Effort
Fulcrum
Class 3 lever
Remember
Velocity ratio = distance moved
by effort ÷ distance moved.
The Home and Workplace
Section B
Simple Machines
Reviewed
Test Yourself:
1. Match the name of the machine to the diagram.
Gears
Gears
Revised
Mastered
Gear A
Gear A
2
Gear B
Gear B
pulley
RA
RA
gears
wheel and axle
inclined plane
1
FA
FA
The torque that rotates gear
B is equal to FA × RA
The torque that rotates gear B is equal to FA × RA
Wheel
Axle
Effort
Inclined plane
Inclined
plane
3
Normal force
Normal force
Load
2. Think about how each one acts as a force multiplier.
How would people use these machines?
Friction
Friction
Horizontal
Horizontal
Weight
Weight
Pulley
Pulley
4
Effort
Effort
Effort
Effort
Load
Load
Load
Load
Pulley system A
Pulley system A
Pulley system B
Pulley system B
Energy Conversion
Reviewed
Revised
Mastered
Simple machines reduce the force needed to move a load. The load and effort are both forces.
Effort
Load
100 N
400
N
Worked Example
If the load was 400 N and the effort was
100 N, the mechanical advantage would
be 400 ÷ 100 = 4.
Remember
Mechanical advantage = load ÷ effort
Forces are measured
in Newtons (N).
The energy put into a lever system is given by: energy input = force × distance moved
The work done by the system: work done = load × distance load moved
73
The Home and Workplace
Section B
Inefficiencies of Machines
Reviewed
Revised
Mastered
Machines have moving parts that need to be properly maintained. Friction between moving parts can
damage them and also use energy. The machine becomes less efficient if the energy required to do work
is wasted as heat because of friction.
The mechanical advantage (MA) of a machine is the ratio of the load to the force or effort needed to
move it.
The mechanical advantage is greater/less if it uses less effort to move a greater load.
The efficiency of a machine can be thought of as the ratio between the total energy put in and the useful
energy out. The energy is the same as the work done.
Mechanical advantage (MA) = Load/effort
Efficiency = useful work output/work input
As a percentage multiply by 100%
Useful work = load × distance load travelled
Work input = effort × distance travelled by effort
74
The Home and Workplace
Section B
Unit
5
Metals and Non-Metals
Concept Map
Uses of metals
Alloys
Physical
properties of
metals
Properties of
non-metals
METALS AND
NON-METALS
Structure of
metals
Reactivity of
metals
Uses of
aluminium
Uses of
plastics
Rusting
Prevention
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can relate the uses of metals and nonmetals to their properties.
I can describe the advantages and
disadvantages of using plastics.
I can compare the reactivity of metals.
I can explain the advantages and
disadvantages of using objects made of
aluminium.
I can evaluate the benefits of using
alloys to make household items.
I can describe the conditions that cause
rusting.
I can identify the factors that affect the
rate of rusting.
I can explain the methods used to reduce
or prevent rusting of iron or steel.
75
The Home and Workplace
Section B
Sh
Properties of Metals
and Non-Metals
Free electrons from outer
shells of metal atoms
+ + + + +
+ + + +
+ + + + +
Metal ions
Test Yourself:
Reviewed
Revised
Mastered
Bell
Metals are made up of positive ions
surrounded by a sea of electrons.
This is called metallic bonding. The
layers can slide over one another. This makes
Bell(pulled
metals malleable (bendy) and ductile
into wires). The free electrons allow metal to
conduct heat and electricity.
Bell
High
po
Shiny
Remember
Lots of energy is needed to break
metallic bonds. Most metals have
highPan
melting and boiling points.
High melting
Shiny
point
Screwdriver
Pan
Shiny
Sonorous
High melting
Link the properties of the metals to their uses. One has been
pointdone for you.
shiny sonorous good heat
conductors
Screwdriver
Bell
Pan
Shiny
Screwdriver
Bell
Pan
High melting
point
Hard
Sonorous
Plug
Necklace
Sonorous
Good heat
conductors
Hard
high melting point hard good electrical conductors
Screwdriver
Pan
Non-metals are brittle and have low
melting and boiling points. They do not
conduct heat or electricity. Non-metals
Screwdriver
have many uses, includingNecklace
as insulators
of heat and electricity. Carbon fibres
are used to make light and strong
sports equipment.
Necklace
Plug
Plug
Hard
Necklace
Sonorous
Test Yourself:
1. Explain why metals are strong but are malleable and
ductile. Good heat
Good electrical
Plug
conductorsused to make wires?
2. Why is copper
conductors
Hard
3. Name a non-metal used in the manufacture of
sports equipment.
Good heat
conductors
Good electrical
conductors
Advantages of Aluminium
Aluminium is the most abundant metal in the earth’s crust. It is
always found
bonded to other chemicals and
be extracted.
Goodmust
electrical
Plug
conductors
There are many uses of aluminium linked to its properties.
There have been claims linking aluminium consumption to
bone and brain diseases, especially in people with kidney
disease. Current evidence suggests that the normal use of
aluminium cooking pans and utensils is safe.
76
Good electrical
conductors
Good heat
conductors
Reviewed
Revised
H
Good
cond
Necklace
High melting
point
Son
Mastered
Properties
Uses
Low density and strong
Aircraft frames
Easy to shape
Drinks cans
Does not corrode easily
Window frames
Good heat conductor
Cooking utensils
Good electrical conductor
Overhead power
cables
Can be polished
Mirrors and fire
fighting suits
Good e
cond
The Home and Workplace
Section B
Uses of Plastics
Reviewed
Some plastics are natural, but most are manufactured from
fossil fuels such as oil. Plastics are very useful because of their
properties. Some properties of plastics are listed here:
Revised
Easy to melt and
form into shapes
Hard or can
be stretchy
Waterproof
Insulators of
heat
Insulators of
electricity
Resistant to
chemicals
Low density
Shock-resistant
Can be coloured
Low cost
Test Yourself: Write down THREE uses of plastics. Explain
how the properties of the plastic make it ideal for each use.
1.
2.
3.
A major problem with plastics is that they are non-biodegradable.
Environmental problems include:
■■ Waste plastic does not rot. It is found as litter on land and at sea
■■ Burning plastics causes air pollution
■■ The manufacturing process uses up oil and causes pollution.
Mastered
Easy to
manufacture
Test Yourself:
1. List THREE properties of plastics.
2. Why are plastics used to form saucepan handles and cases for power tools?
3. Explain the environmental problems caused by the use of plastics.
Reactivity of Metals
Steel structures can rust in a few months but
gold can stay shiny for thousands of years. This is
because some metals are very reactive. Others are
not very reactive.
Reviewed
High reactivity Potassium
Sodium
Lithium
Calcium
We can arrange metals into a league table called
the reactivity series shown here.
Very low
reactivity
Mastered
(K)
(Na)
React with water
(Li)
(Ca)
Magnesium (Mg)
Aluminium (Al)
Zinc
(Zn)
Iron
(Fe)
Tin
(Sn)
Lead
(Pb)
Copper
Silver
Gold
Revised
React with acids
(Cu)
(Ag)
(Au)
77
The Home and Workplace
Section B
Benefits of Alloys
Alloy
Reviewed
Metal composition
Revised
Mastered
Uses
Amalgum
Mercury
Dental fillings
Brass
Copper and zinc
Electrical plugs, door fittings
Solder
Lead and tin
Joining metals
Bronze
Copper and tin
Statues
Stainless steel
Iron, chromium and nickel
Cutlery and kitchen utensils
Remember
An alloy is a mixture of a metal and at
least one other element. This can be
another metal or a non-metal.
Alloys have properties that differ from the pure metal. This can often make them more useful. For
example, an alloy might be stronger or more resistant to corrosion.
Remember
Test Yourself:
1. Which of the following metals will react most quickly with
Though not strictly an alloy,
electroplating coats a cheap metal with
a thin layer of expensive metal.
acids?
lithium
silver
magnesium
copper
2. Give TWO reasons why aluminium is used in cooking pans.
3. Describe THREE uses of alloys.
Rusting
Reviewed
Revised
Mastered
Rusting is a chemical reaction where iron and iron containing alloys react with oxygen
and water. Iron oxide is produced so this is an oxidation reaction.
Remember
iron + water + oxygen → hydrated iron(III) oxide
Other metals can react with oxygen
and other chemicals to form a thin layer
of corrosion. This is sometimes called
tarnishing. The surface becomes dull
and may change colour.
Rust causes many problems. It can make structures such as buildings
and bridges unsafe and damage vehicles, bicycles and items in the house.
Rusty objects also look unattractive.
Test Yourself:
1. What is an oxidation reaction?
2. Describe the problems caused by rust.
3. Define ‘tarnishing’.
78
The Home and Workplace
Section B
Rate of Rusting
Reviewed
Revised
Mastered
Factors affecting the rate of rusting
This experiment shows that both air and water
are needed for rusting to occur. Prevention of rust
involves making sure that air, water or both do not
come in contact with iron or steel.
Oil
Notice that the presence of dissolved salt increases
rusting.
Test Yourself: Complete the table.
Boiled
water
A
Air and
no water
Tube
Tube
A
B
C
D
A
B
Air and
water
C
Salty water
and air
Test Yourself:
1. Explain why metal fixtures rust
D
Water and
no air
Predict the amount of rusting
Predict the amount of rusting
quicker in houses next to the sea.
2. Explain why metal fixtures rust slowly
in houses in dry areas of the world.
B
C
D
Preventing Rusting
Reviewed
Revised
Mastered
Rust can be prevented or reduced by excluding oxygen, water or both from iron and steel.
It is also possible to add elements to iron to lower the rate of rusting. An example of this
is stainless steel – this has chromium and nickel added to the
Increased
•
Very
cold
iron
or
steel
rate
iron.
• Salty water
• Humid air
• Very dry air
• Coating with tin –
galvanised
• Coating with oil,
plastic or paint
• Large surface area
• Coating with another
metal
• Acids such as vinegar
• Additives to the iron
(stainless steel)
• Heating then cooking
Decreased
rate
Galvanising is when a layer of tin
covers iron or steel. Tin is more
reactive, so it corrodes first. The
tin is acting as a sacrificial metal.
Dipping the iron or steel into
molten tin makes the tin layer.
Remember
Electroplating covers iron
or steel with a thick layer
of another metal.
Galvanised objects include doors, metal frames, car parts,
buckets and nails. Household appliances such as washing
machines also have galvanised parts.
Test Yourself:
1. Explain why covering steel with oil or paint can prevent rusting.
2. How does electroplating protect iron and steel objects from rusting?
3. What is galvanising? List THREE examples of galvanised objects.
79
The Home and Workplace
Section B
Unit
6
Acids, Bases and Mixtures
Concept Map
Safety
pH scale
Household
chemicals
Acids
Neutralisation
Bases and
alkalis
ACIDS, BASES
AND MIXTURES
Suspensions,
solutions and
colloids
Hard and
soft water
Detergents
Separation
techniques
Self Check
Tick the box that shows how confident you feel
I can describe the safe and economic
uses of some common household
chemicals.
I can classify some substances as acids,
bases or salts.
I can explain what pH is.
I can define solutions, suspensions and
colloids and give examples.
I can describe separation techniques
such as filtration and distillation.
I can explain the cleaning actions of
scouring powders and detergents.
I can distinguish between hard and soft
water and describe the advantages and
disadvantages.
I can distinguish between soapy (soap)
and soapless detergents.
80
Yes
Maybe
No
The Home and Workplace
Section B
Household Chemicals
1
2
4
Revised
Mastered
Some chemicals can be harmful. If you look
at the labels you will see warning symbols.
3
5
Reviewed
As well as being vital for drinking, water
is important as a solvent. Other chemicals
dissolve in it.
6
Remember
Water is the most common chemical
in the home. Almost all of the other
chemicals contain water.
Test Yourself:
1. What does each of the symbols shown warn us of? Fill in the labels.
2. Name THREE common household chemicals.
3. Why is water the most important household chemical?
Classification of Acids, Bases and Salts
pH
1 M sodium hydroxide (NaOH)
14
12
11
Toothpaste
Baking soda solution
Pure water
10
9
7
Urine
6
Black coffee
5
4
Cola or vinegar
Test Yourself:
1. Name a household chemical that is very acidic.
2. Name a household chemical that is very basic.
3. Why does cola damage your teeth?
8
3
2
Gastric juices
1
1 M hydrochloric acid (HCI)
0
More acidic
Household ammonia
More basic
13
Reviewed
Revised
Mastered
Some household chemicals are acids.
These are chemicals that are corrosive when strong and are irritants
when weak. They react with bases to form neutral compounds. The
acidity or alkalinity of a solution is measured using the pH scale.
Acids have a low pH.
Neutralisation
Acids and alkalis are useful because they can be used to clean objects.
They can also be used to cancel each other out.
Bee stings are acid so they can be
treated with baking soda.
■■ Wasp stings are alkaline so they can
be treated with vinegar.
■■
When acids and alkalis cancel each other
out, we call it neutralisation.
Test Yourself:
1. Explain why farmers add slaked lime (calcium oxide)
to soils that are too acidic.
2. What is the chemical name for vinegar?
3. Describe how you would neutralise vinegar. Which
household chemical would you use?
81
The Home and Workplace
Section B
Reviewed
Revised
Classification of
Suspensions, Solutions and Colloids
Dissolve in
the solvent
Settle
Example
Solution
Yes
No
Brine (salt water)
Suspension
No
Yes
Colloid
No
No
Gas
Gas
Liquid
The air
Liquid
Foams and
sprays
Emulsions
such as hair
oil
Sugar in drinks
Solutions
such as beer
Solid
Smoke
Solutions
such as salty
water
Mastered
Soil in water
Some medicines
Solid
Alloys such
as brass
Milk
Jelly
Foam
Mixtures contain more than one substance. A
mixture can contain solids, liquids or gases but
these substances are NOT chemically joined.
Test Yourself:
1. Give an example of a liquid mixed with a liquid.
2. Describe the differences between a solution
and a suspension.
3. Give TWO examples of colloids.
When substances are added to a solvent
such as water then three results can be seen
as shown in the second table here.
Separation Techniques
The materials in a mixture can be separated
without using chemical reaction. There are
many different types of mixtures. They cannot
all be separated by the same method.
Reviewed
Filtration to separate sand
and salty water
Beaker
Salt/sand mixture
Filter
funnel
Filtration separates large particles
from small particles. Stones and sand can be
separated by using a sieve. A vacuum cleaner
filter separates solids from air.
Filter
paper
Revised
Mastered
Test Yourself:
1. Label the residue
and the filtrate.
2. Why is the salt
NOT trapped by the
filter paper?
Sand
Conical
flask
Distillation is used to separate two
Salt
solution
liquids with different boiling points.
Chromatography can be used to
Distillation of alcohol and water
separate mixtures of coloured compounds
or compounds that can be coloured later.
Chromatography
Cold
water
Alcohol
and water
mixture
Piece of
wood
Pin
In
Paper
Beaker
Out
Alcohol
82
Ink spot
Water
Start
Water
End
Ink
The Home and Workplace
Section B
Test Yourself:
1. Explain why filtration cannot be used to separate salt from water.
2. What is the role of the condenser in distillation?
3. Explain what Rf value is and why it is important.
Safe and Economic Use
of Chemicals
Reviewed
Revised
Mastered
Household chemicals can be harmful. Some are poisonous. Others can irritate the skin. These chemicals
are often acids or alkalis and can damage the environment if thrown away without care.
Read the
advice on
the box
Only use
as much as
necessary
Do not mix
household
chemicals
Wear gloves
and goggles if
recommended
Read
warning
symbols
Safety
Keep chemicals
away from pets
and children
Keep them
in the correct
container
Remember
Wash your hands and
any clothing in contact
with the chemicals
Use chemicals in
a well-ventilated
area
Disinfectants and bleaches work to kill
microorganisms but are poisons so they
must be handled carefully.
Test Yourself:
1. How can you protect children and pets from the dangers of household chemicals?
2. Explain why chemicals should NOT be stored in unlabelled containers.
83
The Home and Workplace
Section B
Cleaning Products
Reviewed
Revised
Mastered
When cleaning appliances that are made from metals such as aluminium, steel, copper, tin and silver you
can use lemon juice or vinegar, but do not use cleaners that contain strong acids.
Cleaning product
Cleaning action
Scouring powders
Abrasive ash mixed with bleaching
agent and detergent
Rust remover
Strong acids such as hydrochloric
acid react with the rust
Limescale remover
Strong acids such as hydrochloric
acid dissolve the scale
Detergents
Chemical binds with both water and
oils to remove dirt
Oxidising agents
Bleaches such as hydrogen peroxide
and chlorine kill microorganisms
and whiten substances
Test Yourself:
1. Which cleaning products contain
strong acids?
2. Why should strong acids NOT be used
to clean aluminium products?
3. Write down the name of ONE
oxidising agent.
Hard and Soft Water
Reviewed
Hard water causes two problems:
■■ Soap does not lather in hard water
■■ Pipes can become blocked with limescale.
water over soft water.
2. How can limescale affect
the efficiency of boilers and
kettles?
Hard
water
Soft
water
Mastered
Remember
S
Test Yourself:
1. List TWO advantages of hard
Revised
Hard water contains dissolved
calcium and magnesium salts. This
is because it flows through rocks
containing these chemicals.
H
Advantages
Disadvantages
Can improve taste
More soap needed
Good for bones and teeth
Scum is made
May reduce heart disease
Can deposit limescale
Lathers with soap easily
No mineral content so no
health advantages
Does not deposit limescale
Does not taste as pleasant
Clothes washed in soft
water last longer
Soap and Soapless Detergents
Reviewed
Revised
Mastered
Soap detergents are called soaps. These are made by heating fats and
oils with concentrated sodium hydroxide to make sodium stearate. This is saponification.
Sodium hydroxide + stearic acid → sodium stearate + water
How detergents work
Water loving head
Water hating
tail
Soap
molecule
84
Water
Grease
Material
The soap or detergent
helps the grease to mix
with the water
Sodium stearate will react with any
calcium ions in water to make calcium
stearate. This stops soap lathering in
hard water.
Remember
Detergents have a detrimental
effect on the environment. This can
be made slightly better by using
biodegradable detergents.
Soapless detergents do not contain
sodium stearate. This means they are not affected by hard water.
The Home and Workplace
Section B
Test Questions for Section B
1. The unit of energy is the:
(a) watt
(b) gram
(c) joule
(d) m/s
2. Chemical → Electrical → Mechanical → Heat
This energy transfer sequence is MOST likely to
occur in a:
(a) solar light
(b) car engine
(c) solar water heater
(d) diesel-powered generator
3. Which of the following machines is MOST likely to
make pushing a pram down steps easier?
(a) Pulley
(b) Lever
(c) Wheelbarrow
(d) Incline plane
4. Current equals:
(a) Voltage × Resistance
(b) Voltage ÷ Resistance
(c) Resistance ÷ Voltage
(d) Voltage + Resistance
5. m in the formula p = mv represents:
(a) mass
(b) pressure
(c) momentum
(d) pressure
6.
(a) What is the function of a simple machine?
(1 mark)
(b) Name TWO simple machines.
(1 mark)
(c) State the formula for the ‘mechanical advantage of a simple machine’.
(1 mark)
(d) A fisherman uses a pulley to apply an effort of 100 N to lift a car engine of weight 1000 N.
Calculate the mechanical advantage of the pulley.
(2 marks)
(e) The pulley was stiff when it was being used. The fisherman applied a lubrication material
to the pulley. Explain why less effort is needed by the fisherman to lift the same load.
(2 marks)
7 The diagram below on the left shows an arm on the completion of lifting an object.
(a) Explain why the action of the biceps, elbow joint and forearm during the lifting
of the object can be referred to as a force multiplier.
(4 marks)
(b) Name the class of lever of the elbow and forearm.
8
The diagram below on the right shows two children playing on a see saw.
Label on the diagram the effort, load and fulcrum.
(1 mark)
(3 marks)
Biceps
Forearm
Elbow joint
85
Earth’s Place in the Universe
Section C
Unit
1
The Universe and Our
Solar System
Concept Map
Location
of Earth
How do
bodies stay in
orbit?
THE UNIVERSE
AND OUR
SOLAR SYSTEM
How Earth
is affected
by other bodies
Human
exploration of
the universe
Self Check
Tick the box that shows how confident you feel
I can list the names of the planets in
order of distance from the Sun.
I know which force keeps the planets in
position.
I can draw the shape of an orbit.
I can list the Moon, Sun and Earth in
order of their mass.
I can explain how we get day and night
on Earth.
I can explain how we get seasons here
on Earth.
I know what a satellite is.
I can describe what we use satellites for.
86
Yes
Maybe
No
Earth’s Place in the Universe
Section C
The Location of the Earth
Reviewed
Revised
Mastered
Test Yourself: Label each of the planets. Use the names of the planets from the box below.
Sun
Sun
Mars
Earth
Mercury
Saturn
Uranus
Venus
Neptune
Explain How Bodies
Stay in Orbit
Jupiter
Reviewed
Revised
Mastered
When objects are close together there is a force between them. This force attempts to pull the objects
together and is called gravity. The force of gravity increases as the mass of the object increases. The
force of gravity on Earth is strong because the planet has a high mass. This keeps us and everything else
on the surface of the Earth. The Sun is 300 000 times bigger than the Earth, which produces a great force
of gravity. The force of gravity from the Sun reaches far out into space. This holds the planets in their
orbit, as they are attracted to the Sun.
Test Yourself:
1. Name the force that keeps bodies in orbit.
2. The force of gravity depends on the mass of a planet . True/False
3. Which solar body holds the planets of the universe in orbit?
Remember
The planets’ orbits are elliptical
(egg-shaped) and not circular.
87
Earth’s Place in the Universe
Section C
How Earth is Affected by
Other Bodies
Reviewed
Revised
Mastered
The Sun and the Moon look about the same size when we look up from Earth. The Sun is actually about
400 times bigger than the Moon. The Moon is much smaller than the Sun but it is closer to Earth. The Sun
is about 400 times further away from Earth than the Moon. The Earth is smaller than the Sun but bigger
than the Moon. As the Moon is closer to Earth it is kept in orbit by the Earth’s gravitational field. It takes
about 28 days for the Moon to orbit Earth.
The Earth spins on its axis. A full rotation takes 24 hours. This gives us day and night. When we are facing
the Sun we have daylight. As the Earth spins away from the Sun we have darkness at night.
Earth also orbits the Sun and this takes 365 and a quarter days. This is the same as a year on Earth.
To incorporate the quarter day we have an extra day in February every four years. Some people call this a
leap year.
The Earth’s axis is slightly tilted. When your part of Earth leans towards the Sun you feel the heat. This is
summer. When it tilts away from the Sun you have less heat and this is winter.
Tilt
Sun
Axis
Earth
Sunlight
Increased
tilt
Northern
Hemisphere
Southern
Hemisphere
88
Sunlight
Earth’s Place in the Universe
Section C
The Solar System
Reviewed
Revised
Mastered
The Earth is not the only planet in the solar system. There are seven others, or eight if you include Pluto.
Here are two examples of mnemonics to help you remember the order of the planets. Try to make
up your own as you will probably remember them better.
Planets in
order of
distance
from the
Sun
Mnemonic
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
My
Very
Easy
Method
Just
Speeds
Up
Naming
Planets
My
Very
Educated
Mother
Just
Served
Us
Nine
Pizzas
Revision Tip: A mnemonic is a good way to remember names and lists. The first letter of the word is
used to make a word that is easy to remember. These easy to remember words are then made into
a sentence.
Human Exploration of
the Universe
Reviewed
Revised
Mastered
Humans have been interested in the universe for many centuries, long before rockets and spaceships.
In the 16th century we believed that the Earth was at the centre of the universe. A Polish astronomer
named Copernicus thought that this was incorrect and that the Sun was at the centre. Galileo agreed
when he observed this with a telescope in the early 1600s.
We have been using satellites to explore space since 1957. Satellites are objects that orbit a planet. The
Moon is the only natural satellite of Earth. Humans have developed man-made satellites that are sent
into space. These satellites provide useful information and photographs of the universe. This is much
safer than sending astronauts into space and less expensive.
89
Earth’s Place in the Universe
Section C
Unit
2
The Terrestrial
Environment
Concept Map
Coastal erosion
Underwater
landslides
Volcanoes
Earthquakes
High/low/spring tides
Causes
Volcanic dust
Tides:
Describe how
formed
Industrial waste
Caribbean
pollutants
Tidal waves
Air masses
Tsunamis
Causes & prevention
of soil erosion
Evaluation of soil
as a resource
Physical & chemical
weathering
Biological action
Radioactive fallout
Cyclonic storms
Types of local
fronts. Consider how
they affect weather
Soil fertility
Composition of humus
Loam
Weather patterns
Hurricanes
THE TERRESTRIAL
ENVIRONMENT
Presence of soil organisms
Sand
Landfill fumes
Seasons
Discuss the factors that
influence soil formation
Soil pH
Sahara dust
Soil
Types and functions
of soil
Clay
Function of seismograph
Soil profiles
Richter scale
Drainage & air content
Volcanic eruptions:
Explain causes of
different types
Relationship
between earthquakes
& volcanoes
Ecological consequences
Kick-em-Jenny
Self Check
Tick the box that shows how confident you feel
I can discuss the factors that influence
soil formation.
I can relate soil fertility to its physical
and chemical properties.
I can identify causes of soil erosion and
methods of prevention.
I can describe the oxygen, carbon and
nitrogen cycles.
I can describe the characteristics of a
cyclonic storm.
I can describe tidal waves.
I can explain the causes of different
types of volcanic eruptions.
90
Yes
Maybe
No
Earth’s Place in the Universe
Section C
Soil Formation
Reviewed
Biological by: movement of plant roots, movement of animals
Revised
Mastered
Physical or mechanical by: water, ice, wind, temperature changes
Chemical by: oxidation, dissolving carbon dioxide
Soil is made up of organic and inorganic materials.
Large rocks are broken down by weathering. There
are three main types of weathering.
Types
and Functions
Physical or mechanical by: water, ice, wind, temperature changes
of Soils
Reviewed
Revised
Mastered
Test Yourself: Match each soil type to its properties.
Sandy
• A mixture of sand and clay,
silt and humus
• Very fertile
Clay
• Large particles
• Spaces between particles trap
air but it is porous
• Limited nutrients as they are
washed away by leaching
Loam
• Tiny particles
• Quite fertile but spaces between
particles hold water that is not
easily drained, causing particles
to swell and stick together
91
Section C
Earth’s Place in the Universe
Physical and Chemical
Properties of Soil
Reviewed
Revised
Mastered
When rocks break down, the minerals they contain are also broken down. That’s why they are different
colours and have different textures and properties. Soil fertility depends on the amount of humus and
the presence of water, air and the right acidity.
Test Yourself:
1. Look at the sedimentation test results. Label the sediments
with the words below.
humus
1
2
clay particles suspended in water
clay
silt
sand
gravel
2. What is humus and how is it formed?
3. Which soil(s) hold(s) the most water? Which soil(s) hold(s) the
3
4
5
6
most air? Which soil is most dense?
4. What other properties could you test the soil for?
Soil Erosion
Reviewed
Revised
Mastered
Soil erosion is the process of removing topsoil. Normally plant roots hold the soil in place, but if there is
little ground cover, rainfall can remove soil.
There are three types of soil erosion:
■■ Sheet erosion – flowing water removes a thin layer of soil
■■ Rill erosion – when water flows quickly over the surface it cuts into the soil. You might have seen this
between rows of crops or where drainage is poor
■■ Gully erosion – flowing water cuts deep into the soil, forming gullies.
If the topsoil dries out during long dry seasons, the surface becomes dusty. The wind can blow the
topsoil away, resulting in soil erosion.
Test Yourself: Suggest ONE method to prevent each process of erosion.
92
Earth’s Place in the Universe
Section C
The Carbon, Water and
Nitrogen Cycles
Reviewed
Revised
Mastered
Test Yourself: Look at the diagrams below and fill in the missing labels.
The Carbon Cycle
Carbon dioxide
in the atmosphere
1
2
Cellular
respiration
Food
Fossil fuels
Death and
decomposition
The Nitrogen Cycle
Excretion, urine,
breathing,
sweating
1
in plant
proteins
Ammonia
in nitrates
and soil
Egestion
Absorption by
2
Decay by
bacteria
The Water Cycle
Precipitation
Condensation
Transpiration
1
Percolation
Run off
Groundwater flow
93
Section C
Earth’s Place in the Universe
Types of Air Masses
Reviewed
Revised
Mastered
The lower section of the Earth’s atmosphere forms air masses. They carry pollutants in addition to
industrial waste and volcanic dust with them.
The four main types are:
■■ Maritime tropical (mT): forms over tropical seas and usually originates in the Gulf of Mexico or the
Caribbean. It is warm and humid
■■ Continental tropical (cT): forms over tropical land. It is dry and hot
■■ Maritime polar (mP): formed over cold ocean water. It is cold and humid
■■ Continental polar (cP): forms in high altitudes over land. It is cold and dry.
Local Fronts and Weather
Reviewed
Revised
Mastered
Air masses move, changing the weather as they go. They don’t mix, they form a boundary when they
meet, called a front or frontal zone. When warm and humid air rises over colder air, any
condensation can result in precipitation at the front of the zone.
A cold front occurs when cold dry air pushes warm, moist air ahead and the warm air rises. Any moisture
condenses and falls as heavy rain. Temperatures drop temporarily.
Warm fronts occur when warm, moist air pushes cold, dry polar air in front. This results in thick clouds
developing, resulting in heavy rain or snow. As the warm front moves forward, the temperature increases
and precipitation decreases.
Stationary fronts result in similar weather to warm fronts and occur when air masses do not move.
Occluded fronts occur when a fast-moving cold front overtakes a slower warm front, resulting in
cloud formation.
Cyclonic Storms
Reviewed
Revised
Mastered
A cyclonic storm is a general name given to all types of storm. They can also be known as hurricanes,
tropical storms or typhoons. They are another result of when air masses meet.
Cyclonic storms need warm seas, greater than 27°C, humidity in the surface air and converging winds.
The warming and cooling of the air causes the winds to blow, resulting in the storm clouds spiralling
towards the centre or ‘eye’. The eye is usually between 15 km and 50 km wide. This is an area of low
pressure and is usually clear and calm. The region surrounding the eye is of high pressure and high
winds. The atmospheric pressure increases as it moves away from the eye to the edge of the storm. The
winds can be up to 240 km/h. Convection currents of rising warm, moist air from the sea and falling
colder air accelerate the force of the winds in the hurricane.
94
Earth’s Place in the Universe
Section C
Tidal Waves
Reviewed
Revised
Mastered
The Earth is made up of plates. If the plates move into each other they can cause earthquakes.
Earthquakes can happen at sea and can push the seabed up by metres. This can displace thousands of
cubic kilometres of seawater. Waves move away from the epicentre at high speeds out in deep water. As
the tidal wave enters shallower water, for example near the coast, the wave slows but increases in size.
The water appears to retreat just before a tidal wave. Tidal waves are NOT the result of tides.
Tides
Reviewed
Moon
Sun
Neap tide
Spring tides
Earth
Revised
Mastered
Tides are the natural rise and fall of sea levels. They are caused
by the gravitational attraction of the Moon and the Sun on
large bodies of water, for example oceans and seas. The Moon
is much closer to Earth than the Sun and as a result has a
greater gravitational attraction than the Sun. Gravity keeps
water on the Earth, but as the Earth spins, the effect changes.
This gives us tides. There are two high tides every day as the
Earth moves closest to the Moon and furthest away. Spring
tides and neap tides occur when the position of the Sun, Earth
and Moon change over a month.
Volcanic Eruptions
Reviewed
Revised
Mastered
A volcano is the result of a build-up of pressure from gases and molten rock below the Earth’s crust.
This finds weakness or faults in the plates at the surface and erupts. As the lava cools, it forms rock
that becomes part of the landscape. The social impact can be devastating. Homes
are destroyed by lava and ash, help cannot get through due to the lava
Remember
and destruction of roads, diseases such as cholera spread because of
Kick-em-Jenny is an underwater
poor sanitation. Jobs are lost and the rebuild is expensive, affecting the
volcano 8 km off the
coast of Grenada.
economy. Volcanic eruptions impact on the environment as the lava
destroys ecosystems and toxic gases are released.
Test Yourself: List as many features for each volcano as you can remember.
1. Cinder cone volcano:
2. Shield volcano:
3. Composite volcano:
95
Earth’s Place in the Universe
Section C
Earthquakes and Volcanoes
Reviewed
Revised
Mastered
The function of a seismograph is to measure the vibrations or seismic waves during an earthquake.
Body
waves
First
P-wave
Surface
waves
First
s-wave
One
minute
(Earlier)
(Later)
Time
Surface waves
P-wave
S -wave
22:20:00
50:00
40:00
50:00
Time (hr-min-sec)
The Richter scale demonstrates the relative size of an earthquake. This is measured by the amount of
damage that results from the tremors of the earthquake.
7
6
Accident
5
4
3
Incident
2
1
0
96
Major accident
Serious accident
Accident with wider consequences
Accident with local consequences
Serious incident
Incident
Anomaly
Deviation
Earth’s Place in the Universe
Section C
Unit
3
Water and the Aquatic
Environment
Concept Map
Hand-fishing
Spear fishing
Nitrates and
phosphates
Eutrophication
Fishing
methods
Pesticides
Oil spills
Life rafts & jackets
Inflatable tubes
Methods of
purifying water
WATER AND THE
AQUATIC
ENVIRONMENT
Chemical and
physical properties
of water
Navigational
devices used
at sea
The conditions for
flotation
Wastage
The home
Sources of water
Desalination
Compass
Sonar
Radar
In life processes
The uses of
water
Upthrust & density
Archimedes’ principle
Dredging
Pots
The effects of
pollution on aquatic
life
Water
safety
devices
Trawling
Compare various
methods
GPS
Growing crops
Drinking
Plimsoll line
Generating electricity
Self Check
Tick the box that shows how confident you feel
Yes
Maybe
No
I can explain the uses of water.
I understand the methods of purifying
water.
I can discuss the chemical and physical
properties of water.
I can state the conditions for flotation.
I can discuss the effects of water
pollution on aquatic life.
I can describe the various methods used
locally for fishing.
I can describe various navigational
devices used at sea.
I can identify water safety devices and
discuss the hazards associated with
scuba diving.
97
Earth’s Place in the Universe
Section C
The Uses of Water
Reviewed
Solutions/solvents/
cleaning agents
Leaking taps
Short showers
Irrigation
Full washing
machine/dishwasher
Reuse water
Mastered
Soap detergent
Growing
crops
Conservation
of water
Running water
Revised
Hydroponics
Washing
Generating
electricity
USES OF WATER
Drinking
Use mulch
Extinguishing
some fires
Water plants
when necessary
Photosynthesis
Aquatic life
Removal
of waste
(toilets)
Test Yourself: Study the concept map. Cover it up and try to recreate it on a blank sheet of paper.
Purifying Water
Reviewed
Revised
Mastered
Most of the water we use comes from freshwater sources. Study the process of purifying freshwater.
Disinfection &
coagulation
Dechlorination
Seawater
Post treatment &
disinfection
Antiscalant
Biocide
RO modules
Product
water
Brine
Multimedia
filter
Filtrate
tank
Safety
filter
High
pressure
pump
Energy
Recovery
Device (ERD)
Test Yourself: Make a step‑by-step guide to the process of desalination.
Remember
Desalination removes the salt
from seawater by a process of
evaporation and condensation.
98
Earth’s Place in the Universe
Section C
Properties of Water
Physical properties of water:
■■ Can exist in all states of matter
■■ Boils at 100°C
■■ Colourless, odourless and tasteless
■■ High specific heat capacity
■■ Good capillary action
■■ 1 cm3 of water has a mass of 1 g
Weight of boat
Revised
Mastered
Chemical properties of water:
■■ pH7
■■ excellent solvent
■■ contains 2 hydrogen and 1 oxygen atom bonded H O
2
Test Yourself: Can you name all of the states of matter
of water?
Flotation
Upthrust of water
Reviewed
Reviewed
Revised
Mastered
Look at the picture of the boat. There are two forces acting on
the boat. The boat is floating because the weight of the boat is
balanced by the upthrust. Archimedes’ principle states that when
an object is immersed in water fully or partially there is an upward
buoyant force acting on it that is equal to the weight of the fluid
that the object displaces. Mass is equal to density multiplied by
volume, so:
upthrust = density of fluid × volume of fluid displaced × g
Remember
density = mass/volume.
(g = acceleration due to gravity = 9.8 m/s2)
The density of water varies according to the temperature and whether it is salty or fresh. Upthrust
depends on the density. The Plimsoll line is a reference mark on the hull of ships. It indicates the
maximum depth that the ship can safely be immersed to when loaded with cargo. The line takes into
account the density of the water in all conditions.
Water Pollution
Reviewed
Revised
Mastered
Most pollutants are from human activity. The main sources of pollution are:
■■ Sewerage from treatment plants and farming
■■ Oil spills from oil rigs and tankers
■■ Effluent from refineries and factories
■■ Hot water from factories
■■ Detergents and washing products
■■ Heavy metals from industrial waste
■■ Pesticides and fertilisers from farming.
Fertilisers and sewerage entering the water system can result in algae and other aquatic plants growing
rapidly. This is known as algal blooming. The plants and algae use lots of oxygen to respire and also
prevent plants underneath them from photosynthesising. The adding of nutrients to the water in this
way is known as eutrophication.
99
Earth’s Place in the Universe
Section C
Fishing
Reviewed
Revised
Mastered
Test Yourself: Look at the diagram of the methods of fishing and highlight which of the methods
are used locally.
Purse-seining
to catch large amounts
of tuna
By hand
Metal
Bamboo
Pots and
traps
METHODS
OF FISHING
Just hands, no tools
Spears
Spearing
Harpoons
Rod
Line
Bait
Using lines
Netting
(commercial
fishing)
Lift net/large scoop
Entanglement between boats
Trawling boats with nets
Navigational Devices
Scoop net
Close to water’s surface
Cast net
Circular net thrown out to sea
Dredging
Dragging along seabed
Reviewed
Revised
Mastered
The magnetic compass is one of the oldest navigational devices. The needle on the compass lines up
with magnetic North on Earth. They are often used with other devices and maps to determine the
position of the vessel.
Sonar or echo sounder finds large numbers of fish. Pulses of sound are sent into the water. If they hit an
object, they reflect back to instruments on the ship.
Radars use radio waves to detect objects, for example ships up to 40 km away. They show up as blips.
GPS (global positioning system) is a satellite navigation system. This reduces the chance of a ship being
lost at sea.
100
Section C
Water Safety Devices
Earth’s Place in the Universe
Reviewed
Revised
Mastered
Life jackets are made from strong but lightweight materials. They can be inflated when needed and act
as a flotation device. Life jackets can also be inflated by blowing into a tube if they do not automatically
inflate. They have adjustable ties to allow them to be used by most people when needed.
Life rafts are for use in an emergency when on or near water. They are also made from strong but
lightweight materials. They inflate automatically to be used as a flotation device.
Inflatable tubes are made from a number of lightweight materials that are capable of floating. These can
be used as a flotation device.
Scuba Diving
Reviewed
Revised
Mastered
Hazards associated with scuba diving are:
■■ Heat loss, as water is a good conductor of heat, better than air. This can lead to hypothermia
■■ Increased amounts of nitrogen absorbed into the blood and tissues can be released
as bubbles if the diver ascends too quickly. This can cause ‘the bends’ or
decompression sickness (DCS)
Remember
■■ Increased amounts of nitrogen are absorbed into the blood and
Scuba stands for Self-Contained
tissues when divers increase the depth of the dive. This can lead to
Underwater Breathing
Apparatus.
nitrogen narcosis
■■ Pressure increases with depth. If the diver descends quickly, it can cause
damage to the ears, lungs and eyes.
101
Earth’s Place in the Universe
Section C
Unit
4
Fossil Fuels and
Alternative Sources
of Energy
Concept Map
Loss of energy
in conversion
Solar water
heaters
Solar cells
Types of
fossil fuels
Appraise the extent
that alternative energy
sources can be used in
the Caribbean
Energy obtained
from petroleum =
stored energy
The sun (solar)
FOSSIL FUELS AND
ALTERNATIVE
SOURCES OF ENERGY
Alternative
sources of
energy
Conduction
Convection
Radiation
Biogas
Geothermal
Hydroelectric
Variables
affecting solar &
wind energy
Biodiesel
Problems
associated with the
use of fossil fuels
Non-renewable
Environmental effects
Acid rain
Global warming
Self Check
Tick the box that shows how confident you feel
I can identify the types of fossil fuel.
I can identify the energy obtained from
petroleum as stored energy.
I can discuss the problems associated
with the use of fossil fuels.
I can identify alternative sources of
energy.
I can discuss the uses of solar and wind
energy and the variables affecting them.
I can appraise the extent to which
alternative sources of energy can be
used in the Caribbean.
102
Yes
Maybe
No
Earth’s Place in the Universe
Section C
Types of Fossil Fuels
Test Yourself:
1. Why are they called fossil fuels?
2. Recall how they were formed and how long
Reviewed
Revised
Mastered
Dead plants and animals decay
Result:
this took.
3. Join the boxes to demonstrate the process of
the formation of fossil fuels. Write the name of
the fossil fuel produced in the space provided.
from trees and animals
from dead marine organisms
from dead marine plants
and animals
Covered with silt adding pressure, raising
the temperature and keeping out oxygen
Energy from Petroleum
Reviewed
Revised
Mastered
Petroleum is used to produce other fuels, for example gasoline, diesel and kerosene.
Petroleum is made from decaying plants and animals.
Remember
Test Yourself: Where do plants and animals get their energy?
Name the process.
Problems Associated with
Using Fossil Fuels
The gasoline used in vehicles today has
been stored as a result of this process
from millions of years ago.
Reviewed
Revised
Mastered
Non-renewable: why can’t we make more fossil fuels? Think back to the process of producing fossil
fuels
■■ Environmental effects of acid rain: when fossil fuels are burned, gases are formed. Sulphur dioxide,
carbon dioxide, carbon monoxide, nitrogen dioxide and lead compounds in addition to water
vapour contribute to environmental problems. Sulphur dioxide and nitrogen dioxide dissolve in rain
water, becoming acidic. This contributes to acid rain
■■ Global warming: radiation from the Sun is trapped on Earth by greenhouse gases such as carbon
dioxide
■■ Acid rain: gases are dissolved in the water in the atmosphere. When they condense they precipitate
as acid rain.
■■
103
Section C
Alternative Sources of
Energy in the Caribbean
Earth’s Place in the Universe
Reviewed
Revised
Mastered
Energy can be generated from other fuel sources as well as from fossil fuels. Examples include: biogas,
wind, wave, biofuels, geothermal, hydroelectric and biodiesel sources.
Test Yourself: Write a short explanation of how energy is obtained from each of the processes
listed above.
Solar energy is readily available in the Caribbean. It has been used to cook and dry food for many
years. A solar cooker has a reflective surface that directs radiation to the centre of the cooker where it is
transferred to the food.
Test Yourself: Why are solar panels and photovoltic cells usually black in colour?
Solar cells or photovoltaic cells convert light energy to small amounts of electricity directly. Only
10% of the energy that radiates towards the cell is transferred to electrical energy; 90% is lost in
the conversion.
Electricity can also be generated from moving water as it falls from a higher level or from high tides in
the Caribbean. Wind energy is used to generate electricity, for crop drying, irrigation and refrigeration.
Biomass from animal excretion and the fermentation of decomposing plants is also used as an
alternative source of energy. This can be used to fuel vehicles as an alternative to gasoline.
Geothermal energy is used to heat water directly or in the production of electricity.
Solar and Wind Energy
Reviewed
Revised
Mastered
Solar cells convert light energy into electrical energy, for example in calculators and lighting. Solar
panels do not result in electrical energy; they use the energy from the Sun to heat up water. This can
be used in heating systems to heat buildings or just to produce hot water. The same method is used to
cook and dry food.
Wind turbines generate electricity without the need to burn fossil fuels. Wind turbines transfer
kinetic energy from the wind to electrical energy.
104
Section C
Variables Affecting Solar
and Wind Energy
Earth’s Place in the Universe
Reviewed
Revised
Mastered
There are many factors that can make an impact on the amount of energy generated from wind. The
output of the wind turbine is dependent on the wind speed. The greater the wind speed, the more
power is generated. Not all of the energy is transferred to electrical energy.
Test Yourself: Suggest an energy transfer that takes place in a wind turbine that is NOT useful.
Solar energy is efficient, but the energy transferred is dependent on the amount of radiation that reaches
and is absorbed in the conversion process.
105
Earth’s Place in the Universe
Section C
Unit
5
Forces
Concept Map
Centripetal force in satellites
Stable
The relationship between height of an
object, centre of gravity & its stability
Types of
equilibrium
Describe gravity
as a force
Maximum of load capacity
Unstable
Neutral
FORCES
Action
Reaction
Types of force
Newton’s Third Law
Wing shape in birds and aircraft
Friction & motor vehicles
Conditions
of equilibrium
& gravity
The principles
of forces
Wind speed and current on aircraft
Self Check
Tick the box that shows how confident you feel
I can discuss the basic principles of
forces.
I can describe gravity as a force.
I can explain the centre of gravity.
I can explain the types of equilibrium as
stable, unstable or neutral.
106
Yes
Maybe
No
Earth’s Place in the Universe
Section C
Principles of Forces
Reviewed
Revised
Mastered
A force is a push, pull or twist that can make a stationary object move, make a moving object change
direction or change the shape of an object. Where two or more forces act on an object, the resultant
force is the sum of them all.
This explains the forward motion of a jet engine. The force (action) of the
exhaust gases pushing backward produces an equal and opposite force
(reaction) called thrust that powers the jet forward.
Test Yourself: Look at the diagram of a wing.
Explain how the shape of birds and aircraft wings exerts
a lifting force.
Remember
Newton’s third law of motion:
for every action there is an equal
and opposite reaction.
Lift
Faster moving air
Slower moving air
Remember
Friction opposes motion.
Gravity and Centre
of Gravity
Reviewed
Revised
Mastered
Gravity is a non-contact force that holds objects on the surface of the Earth. Other planets and satellites
are held in position or orbit by the force of gravity. All objects have mass, and gravity acts on mass.
The centre of gravity of an object is the point where it can balance. The stability of an object is
determined by how easy it is to topple over. Stable objects topple over with great difficulty. Objects with
a wide base and low centre of gravity are the most stable.
Vehicles are given a maximum loading capacity and tare depending on the width of the wheel base and
the height of their centre of gravity to maximise the stability.
Equilibrium
Reviewed
Revised
Mastered
If an object is stationary and is not toppling over then it is in equilibrium. The centre of gravity is directly
above the base that it is standing on.
Centre of gravity
Car topples
Car does not
topple over
Look at the diagram showing the centres of
gravity. The one on the left topples because
the load is not stable. The one on the right
has a much lower centre of gravity and is
much more stable.
Remember
The force of gravity
exerted by Earth pulls on
the centre of gravity.
If the base of a vehicle is small, the weight needs to be added low down.
This will keep the centre of gravity low.
107
Earth’s Place in the Universe
Section C
Test Questions for Section C
1. Which of the following keeps the planets orbiting around the sun?
(a) Gravitational energy
(b) Electromagnetic energy
(c) Nuclear radiation
(d) Electrostatic forces
2. Which of the following gases is thought to be the LEAST likely to contribute to global warming?
(a) Methane
(b) Carbon dioxide
(c) Oxygen
(d) Nitrous oxide
3. The remains of plant and animal matter found in soil is called:
(a) Loam
(b) Clay
(c) Humus
(d) Chalk
4. The major cause of the tides on earth is the:
(a) Solar flares and radiation emitted from the sun
(b) Daily spinning of the earth on its axis
(c) Orbiting of the earth around the sun
(d) Gravitational attraction of the moon and sun
30
440
450
5. The diagram above shows the mass of carbon dioxide released into and removed from the air each year in
billions of tonnes. Describe the three processes shown on the diagram that exchange carbon dioxide with
the air.
(i)
(ii)
(iii)
(3 marks)
6. Explain the overall effect of these processes on the mass of the carbon dioxide in the air.
108
(3 marks)
Paper 1 Practice Questions
Paper 1 Practice Questions
1. Which state of matter has a regular shape and high
density?
(a) Liquid
(b) Solid
(c) Colloid
(d) Gas
2. Which of the following organelles is NOT found in
animal cells?
(a) Chloroplast
(b) Mitochondria
(c) Nucleus
(d) Cell membrane
3. Which of the following is a plant gamete?
(a) Bulb
(b) Sperm
(c) Pollen
(d) Corm
4. Which of the following enzymes digests protein?
(a) Amylase
(b) Lipase
(c) Maltase
(d) Pepsin
5. Which of the following are products of
photosynthesis?
(a) Carbon dioxide and water
(b) Glucose and carbon dioxide
(c) Chlorophyll and oxygen
(d) Glucose and oxygen
6. Which of the following components of blood aid
clotting?
(a) Red blood cells
(b) Platelets
(c) White blood cells
(d) Plasma
8. The energy conversion sequence describes which
mechanism:
chemical → electrical → light
(a) Solar light
(b) Calculator
(c) Solar radio
(d) Solar water heater
9. The formula ρ = mv is used to calculate:
(a) Speed
(b) Temperature
(c) Resistance
(d) Momentum
10.
This symbol represents this part of a circuit:
(a) Battery
(b) Ammeter
(c) Switch
(d) Bulb
11. A class 1 lever has the:
(a) Load and effort on the opposite sides
(b) Fulcrum and effort in the middle
(c) Effort between the load and the fulcrum
(d) Fulcrum between the effort and the load
12. The pH of a strong acid will be:
(a) pH 1
(b) pH 10
(c) pH 7
(d) pH 3
13. Which of the following statements about the moon
is correct?
(a) It is a star
(b) It is a satellite
(c) It orbits the sun
(d) It has oceans of water
7. Water urea and salts are excreted from the:
(a) Kidneys and skin
(b) Kidneys
(c) Lungs
(d) Skin
109
Paper 2 Practice Questions
Paper 2 Practice Questions
1. Distinguish between d.c current and a.c. current.
(2 marks)
2. Name a suitable material that is used to insulate electrical wires.
(1 mark)
3. An electricity company charges $1.00 per kWh for the first 2000 kWh and $3.50 for every kWh after that.
There is a fuel adjustment charge of $0.50 per kWh added to all electricity bills. If the previous meter reading
is 17 800kWh and the current reading is 20 300 kWh, calculate the electricity bill for the current month.
(5 marks)
4. Define the term “machine”.
(1 mark)
5. State the formula used to calculate the mechanical advantage of a machine.
(1 mark)
6. Define the following terms:
(i) Centre of gravity
(1 mark)
(ii) Stable equilibrium
(1 mark)
7. A load of 50 N is applied 10 m away from the fulcrum of a lever.What is the distance at which an effort of 100
N should be applied to ensure that the lever remains at equilibrium?
(5 marks)
110
Answers To Test Yourself Questions
Answers To Test Yourself
Questions
Section A
Three States of Matter: TY#1: 1. fixed volume; 2.
not easily compressed; 3. takes the shape of bottom of
container; 4. no fixed volume; 5. low density; 6. easily
compressed; 7. particles free to move. TY#2: 1. Gas; 2.
There is less space between the particles.
Plant and Animal Cells: TY#1: 1. starch grain; 2.
cell membrane; 3. cell wall; 4. mitochondria; 5. nucleus;
6. vacuoles; 7. cytoplasm; 8. glycogen granule; 9.
Chloroplast. TY#2: Nucleus: both. Cytoplasm: both. Cell
wall: plant only. Cell membrane: both. Mitochondria:
both. Chloroplasts: plant only. Vacuoles: plant only.
Starch grains: plant only. Glycogen granules: animal
only.
Functions of Cell Components: 1. nucleus:
contains the genetic material of the cell; cell membrane:
controls exchange of materials; cytoplasm: where
most of the cell’s chemical reactions occur; chloroplast:
site where photosynthesis takes place; mitochondria:
site where energy is produced during respiration. 2.
Nucleus, cytoplasm, cell membrane, mitochondria. 3.
Mitochondria, cytoplasm. 4. Cell membrane.
Diffusion, Osmosis and
Active Transport: TY#1:
High solute
concentration
Low water
concentration
Low solute
concentration
High water
concentration
Sexual Reproduction In Plants and
Humans: Petal is brightly coloured and scented to
attract insects. Stamen contains anther and filament
produces and contains the male gamete. Pistil is several
carpels fused together and produces and contains the
female gamete.
Fertilisation: 1. Anther. 2. Increases variety in the
offspring. 3. The ovule develops into a seed containing
the embryo. The petals, stigma, style and stamens drop
off as the ovary grows into a fruit that contains one or
more seeds.
The Menstrual Cycle: 1. During the menstrual
cycle an ovum is released into the uterus. The uterus
changes in preparation for supporting a fertilised egg.
If fertilisation does not take place, menstrual bleeding
occurs. This is controlled by hormones. 2. Progesterone
makes the womb’s lining thicker and prepares the
breasts for milk production. 3. Menopause is when the
menstrual cycle and periods stop and a woman is no
longer able to become pregnant.
Ovulation to Birth of a Foetus: 1. An ovum or
egg is mature and is released from a follicle in the ovary
and passes into the fallopian tube. Tiny hairs called
cilia help the ovum to travel along the fallopian tube.
2. A zygote is a fertilised ovum. 3. Oestrogen starts the
building of the lining of the uterus.
Methods of Birth Control: 1. Abstinence and the
condom. 2. This method is not reversible.
Partially permeable
membrane – like a
cell membrane
TY#2: 1. Bacteria, fungi, protozoa, algae, viruses; 2. You
can smell perfume because it diffuses into the air and
makes its way into your nose; 3. Osmosis is important
to plants as they gain water by osmosis through their
roots. Water moves into plant cells by osmosis. Some
cells rely on active transport for their functions – it
allows molecules that cannot enter the cell by osmosis
to enter the cell.
Asexual Reproduction in Plants and
Animals: 1. A bulb is an underground food-storage
organ that develops into the following year’s plants. A
runner is a side branch with plantlets on it. 2. Cutting:
a leafy branch or cutting is taken from a plant and
planted. Grafting: this is similar to budding but this
time a small branch is attached to the other plant.
Pre- and Post-Natal Care of Mothers and
Babies: TY#1: 2. healthy/calcium/vitamins. 3. alcohol
and nicotine. 4. X-ray. TY#2: 1. Breast-feeding helps
with protection against disease as the milk contains
essential nutrients and antibodies against diseases. 2.
Any two from: urine testing for diabetes and urinary
tract infections; weight monitoring to see if the mother
is eating properly and the baby is developing well;
ultrasound to monitor the development of the baby;
blood tests for Rhesus factor, iron level and immunity to
diseases such as rubella.
STDs: 1. abstinence; male and female condoms; keep
to one sexual partner. 2. Antibiotics are used to treat
bacterial infections.
Growth Patterns: 1. 12 years; 2. 14 years.
Human Population Control: 1. open answer;
2. Any of: birth rates are higher where child labour
is prevalent, people living in urban areas tend to
have fewer children, birth rates tend to be lower
in developed countries, where raising children is
expensive, birth rates tend to be low when women
have access to education and paid employment
outside the home, in areas with low infant mortality
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Answers To Test Yourself Questions
rates, people tend to have less children because fewer
children die at an early age, women have fewer children
when their average age at marriage is 25 or older; 3.
Outbreaks of disease are more frequent and severe in
areas with a high population density. Cramped living
conditions also harm family relationships; negatively
affect children’s education and cause depression, stress
and anxiety.
Photosynthesis: 1. sugar (glucose) and oxygen; 2.
Carbon dioxide enters via leaf stomata by diffusion.
Water is absorbed through the roots and is transported
to leaves through the xylem; 3. If it gets too cold, the
rate of photosynthesis will decrease, but plants cannot
photosynthesise if it gets too hot. The rate will rise until
it is too hot and then it will drop off again.
Crop Production: 1. Contour collects and preserves
water and terracing prevents run off. 2. Control of pests,
temperature, water, amount of sunlight to increase
overall yield.
Food Chains and Webs: 1. Omnivore. 2. They
transfer energy from the sun. Animals cannot do this.
3. The herbivores would not have any food and would
die out. The energy along the food chain to the shark
would die out.
The Importance of Food: 1. Rickets, scurvy or
kwashiorkor. 2. Carbohydrates and fats 3. Protein. 4.
The construction will be moving around and lifting
things. He will need more energy to carry out these
tasks. The office worker will be sat down mostly and
using less energy.
Growth of Microorganisms: 1. Keep the food
away from microbes. Keep the essential factors for
microbe growth away from the food, including warmth,
air, moisture and food. Washing hands and cooking
food well reduces the risk of contamination. 2. As
microorganisms grow they can produce toxins. 3. Many
microorganisms reproduce by binary fission. They grow
and then divide in two. This means that every time the
microorganisms reproduce, the population doubles.
Food Preservation: 1. Keep the food away from
microbes. Keep the essential factors for microbe
growth away from the food, including warmth, air,
moisture and food. Washing hands and cooking
food well reduces the risk of contamination. 2. As
microorganisms grow they can produce toxins.
Human Digestion: 1. Absorption: taking food
through the wall of the small intestine. Folds called
villi increase the surface area of the wall. Assimilation:
absorbed food is taken into cells. 2. They are thin with a
large surface area which is increased by a lining of villi.
3. Amylase helps your body break down starch. Lipase
helps your body digest fats.
Human Teeth: 1. 1 incisors, 2 canine, 3 pre-molar, 4
molar. 2. From top to bottom: incisors, canine, molars,
pre-molars.
Transport Systems: 1. Human: 1. veins, 2. brain,
3. lungs, 4. heart, 5. arteries, 6. stomach, 7. rest of
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body, 8. liver; plant: 1. evaporates, 2. leaves, 3. stem, 4.
roots, 5. water and minerals are taken up by the roots,
6. root hairs. 2. In multicellular organisms many of
the cells will not be near the surface. Materials have
to be transported around the organism. 3. Diffusion
pathways and concentrations gradients are more
efficient.
Structure and Function of Transport
Systems: 1. Right atrium, right ventricle, left ventricle
and left atrium. 2. Arteries. 3. The main function is
to carry oxygen. 4. Xylem tubes transport water and
dissolved substances from the roots to the leaves.
Phloem tubes transport food and waste products
from where they are made to where they are needed.
5. Water is transported into the roots and then into
the xylem. The forces of cohesion and adhesion cause
the water molecules to form a column in the xylem.
Water moves from the xylem into the mesophyll cells,
evaporates from their surfaces and leaves the plant by
diffusion through the stomata.
Blood Groups: 1. Only type O. 2. This is a protein
found in the red blood cells of some people. These
people are Rhesus positive (Rh+). If Rh+ blood is given
to a Rh− person then this causes agglutination. If a
mother is Rh+ and her unborn baby is Rhesus negative
(Rh−) this also causes problems.
Cardiovascular Disease: 1. Caused by a
hardening of the arteries, so they are not elastic. This
can be the result of age or fatty deposits of cholesterol.
2. Poor diet, stress, alcohol and nicotine all affect heart
health.
Immunisation: 1. These either burst the cells or
attract white blood cells (phagocytes) which engulf
and destroy the microorganisms. 2. White blood cells
of the immune system recognise a pathogen in the
body. This starts the growth of lymphocytes and their
multiplication and final production of antibodies. The
antibodies stick to the antigens on the pathogens
and destroy them. 3. A vaccine contains weakened or
killed disease microorganisms. The body recognises the
antigens and produces antibodies. This prepares the
body in case a person is infected later with the actual
disease.
Drug Use: 1. Any of: alcohol, prescription drugs,
non-prescription drugs, illegal drugs, steroids, diet
pills and hormonal injections (HCG). 2. Blood is taken
from an athlete and stored. It is later added before a
competition so the athlete has more red blood cells.
The Physiological Effects of Exercise: 1.
Increases; 2. Improves; 3. Fat, increases; 4. Digestion;
5. Circulation; less.
The Human Skeleton: 1. A. Cranium, B. clavicle,
C. humerus, D. scapula, E. vertebral column, F. pelvic
girdle, G. radius, H. ulna, I. femur, J. patella, K. fibula, L.
tibia. 2. Femur, platella, fibula and tibia. 3. Humerus,
radius, ulna.
Function of the Human Skeleton: 1. The rigid
ribs make sure the chest does not collapse onto the
Answers To Test Yourself Questions
lungs. This would stop us breathing. Blood vessels are
also protected by bone. 2. Cranium. 3. Holds organs
and muscles in position.
Joints and Muscles: TY#1: 1. The ball and socket
joint is also known as a spheroidal joint. This is a type
of synovial joint where the ball-shaped surface of a
rounded bone fits into the cup-like shape of another
bone. 2. Ankle, elbow or knee. TY#2: 1. The triceps and
biceps control the movement of the elbow. The bicep
shortens or contracts. This pulls the lower arm up and
the elbow bends. The tricep then relaxes or lengthens.
When the tricep contracts, the lower arm is pulled
back down and the bicep relaxes. 2. It strengthens the
muscle and it increases in size.
Breathing: Notice that when the diaphragm moves
downwards, the intercostal muscles move the rib
cage upwards and out. This decreases the internal air
pressure and so air from the outside moves into the
lungs. The opposite happens during breathing out.
Gaseous Exchange: 1. Diffusion is the movement
of particles from a high concentration to a low
concentration. In the lungs, oxygen moves from
the high concentration in the alveolar air spaces to
the lower concentration in the blood. 2. When the
concentration of carbon dioxide is higher in the lungs,
it moves along the concentration gradient to the
blood. 3. Inhaled air contains a higher concentration of
oxygen and so moves into the blood. Exhaled air has a
higher concentration of carbon dioxide.
Importance of Respiration: 1. Carbon dioxide,
water and energy. 2. Mitochondria in the cell. 3. We use
energy for all life processes.
Aerobic and Anaerobic Respiration: 1.
From top to bottom: Complete/Not needed/Greater
amounts/Energy. 2. The lactic acid builds up in the
muscles and can cause cramp. 3. Anaerobic respiration
produces alcohol as a by-product when it happens in
plants and yeast. 4. The process is incomplete.
Causes of Air Pollution: 1. Combustion of fossil
fuels, incomplete combustion, toxins in batteries,
keeping animals. 2. Incomplete combustion of fuels.
Problems Caused by Air Pollution: 1. Open
answers such as: smoking cigarettes/cigars, chewing
tobacco, smoking cannabis, exposure to other people’s
tobacco smoke (passive smoking), exposure to
chemicals used in industry e.g. arsenic and asbestos. 2.
Smoking, second-hand smoke, smoky environments,
inhaling air pollution at work. 3. Asthma, bronchitis. 4.
The recycling of carbon dioxide from the atmosphere
would be stopped if the gas could not enter the
stomata.
The Effects of Smoking: 1. Damages alveoli and
cilia. Makes it difficult to breathe and gas exchange
is reduced. Increases heart rate and blood pressure.
May cause strokes and heart attacks Bonds with
haemoglobin in red blood cells. Causes breathlessness.
2. This can damage alveoli and cilia. Makes it difficult to
breathe and gas exchange is reduced.
Excretion by the Lungs, Skin and Kidneys: 1.
cortex; 2. Bowman’s capsule; 3. glomerulus; 4. Loop of
henle; 5. medulla.
Waste Products of Flowering Plants: TY#1:
water
carbon dioxide
TY#2: 1. Stomata are openings on the underside of a
plant. They allow the exchanges of gases. 2. Carbon
dioxide and oxygen. 3. Waste products can also be
collected in the bark and leaves of trees. When the
leaves fall this waste material is excreted.
Sense Organs and Their Functions: 1. Top to
bottom: nose, tongue, skin, eye, ear. 2. Touch, pressure,
pain and temperature. 3. Receptors are the groups
of specialised cells that can detect changes in the
environment, which are called stimuli, and turn them
into electrical impulses.
The Mammalian Eye: TY#1: Cornea: Controlling
light. Retina: Detecting images. Optic nerve: Carries
impulses to the brain. Iris: Protection. Lens: Focusing
light. TY#2: 1. Too much would damage the optic
nerve. 2. Rods are light-sensitive cells that allow us to
see black and white. Cones are light-sensitive cells that
allow us to see colour. 3. The focal distance between
the eye and the object is changed.
Natural and Artificial Light: 1. Artificial light is
made by humans. Examples are light bulbs, candles,
televisions and fireworks. 2. The sun, glowing lava,
lightning and glow-worms are sources of natural light.
3. The spectrum of artificial light is not as broad as
natural light.
Transparent, Translucent and Opaque
Materials: 1. 1 opaque; 2 translucent; 3 transparent.
2. To allow light to pass through. 3. Opaque. It blocks
the light.
Components of White Light: 1. The colours in
white light are refracted and dispersed when they enter
a transparent substance. The colours have a different
wavelengths and slow down by different amounts.
2. Red, orange, yellow, green, blue, indigo and violet.
3. No: black is the absence of colour and white is the
blending of all colours together.
Sight Defects: TY#1: Figure 2. TY#2: 1. Corrected
by glasses with concave lenses. 2. Any three from age,
injury, diabetes or life choices such as smoking and
heavy alcohol drinking. 3. Damage to the optic nerve
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Answers To Test Yourself Questions
can result in vision problems and blindness. With early
detection, glaucoma can be treated.
foods. Microorganisms need water to multiply. 3. To
prevent microorganisms contacting the food.
The Mammalian Ear and Function: TY#1: 1
pinna; 2 anvil; 3 hammer; 4 stirrup; 5 semi circular canal;
6 cochlea ; 7 eustacian tube; 8 tympanic membrane;
9 auditory canal. TY#2: 1. It separates the outer and
middle ear. It reacts to sound waves by vibrating and
passes on the vibrations to the ossicles. 2. Sound
waves travel down the auditory canal to the cochlea.
The vibrations are converted into electrical signals in
the cochlea. 3. Semi-circular canals. 4. This is a narrow
passage leading from the pharynx to the cavity of the
middle ear. It equalizes the pressure on either side of
the ear drum.
Types of Waste: 1. Electronic waste includes
unwanted refrigerators, microwaves, phones and
computers. 2. These may contain harmful chemicals
such as the toxic metals lead and mercury. 3. Any
uncovered food waste can attract pests such as flies
that will spread diseases.
The Nervous System: 1. Voluntary actions are
those actions that require thought. Involuntary actions
are reflex actions and occur quickly and without
thought. 2. They protect us from the outside world
by acting quickly to stimulus. 3. Damaged nerve or
neurological signals may not be passed.
The Endocrine System: 1. Thyroxine’s main
function is to stimulate the intake of oxygen and so
impacts on the metabolism of all cells and tissues in
the body. 2. Adrenocorticotrophic hormone (ACTH);
thyroid-stimulating hormone (TSH); luteinising
hormone (LH); follicle-stimulating hormone (FSH);
prolactin (PRL); growth hormone (GH); melanocytestimulating hormone (MSH). 3. It controls the functions
of many of the other endocrine glands.
Personal and Community Hygiene: TY#1: 1. 1,
3, 4 and 5. 2. 1. TY#2: 1. It helps us to stay healthy and
prevent microorganisms causing diseases. 2. To prevent
the spread of infections.
Household Pests and Parasites: TY#1: Rats
and mice: steal human food, damage clothing.
Houseflies: biting. Cockroaches: stealing human food.
Mosquitoes: biting, cause disease. TY#2: 1. Rats and
mice, houseflies, cockroaches, mosquitoes. 2. How
do pests cause problems for humans? They carry
disease. 3. Parasites are organisms that live on or in
another living organism and feed on it. A pathogen is
a microorganism that causes disease. Pathogens are
infectious agents that can cause disease.
Life Cycle of a Mosquito: 1. Mechanical: clearing
bushes near homes, removing stagnant water, covering
windows with mesh. Chemical: removing stagnant
water, covering water with oil, spraying insect repellent.
2. Mosquitos lay their eggs in or near to water.
Control of Pests: 1. physical = 3 e.g. mosquito net;
2. biological = 4 e.g. introducing lady bugs; 3. chemical
= 2 e.g. disinfectant use; 4. sanitary = 1 e.g. cleaning a
floor.
Food Preservation: 1. Microorganisms need
warmth to multiply. 2. Osmosis removes moisture from
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Solid Waste and the Environment: 1. It can end
up on unused land, it can be buried or it can be burned.
This type of disposal looks ugly and causes air and
water pollution as well as attracting pests such as rats.
2. Paper, cardboard, glass, cans 3. They decompose and
do not stay in the environment for many years.
Section B
Thermostatically Controlled
Appliances: Steel, copper and brass.
Concept and Unit of Energy: 1.running; 2.
battery; 3. light bulb; 4. heating water; 5. music; 6. food
; 7. fire; 8. fusion or fission; 9. stored energy in a spring.
Inter-Conversion and Conservation of Mass
Energy: 1. Photosynthesis. 2. It can never be lost or
made but converted from one form to another.
Transfer of Energy: 1. By placing a mirrored sphere
behind the bulb. 2. Transmitter → satellite → receiver →
TV.
Conductors: 1. Any metal would be a good
conductor. Copper is one of the most commonly used.
2. To insulate them and prevent the flow of energy into
us.
V=IR: TY#1: 4 Ω. TY#2: Row 1: ammeter, lamp. Row
2: cell, transformer. Row 3: fuse, switch. Row 4: voltmeter,
resistor.
Fuses Work as Safety Devices: TY#1:
Earth wire
Neutral
wire
Fuse
Live wire
Outer insulation
TY#2: The fuse acts as a safety device and putting
the wrong one in will reduce its effectiveness and be
dangerous. If you put a bigger fuse in then the fuse no
longer becomes the weak link and if you get a surge of
power you are more likely to cause a fire.
Answers To Test Yourself Questions
Calculate the Amperage for Fuses and
Flexes: To allow enough current to travel to the
appliance without melting the wire in the fuse.
Energy Calculations: The equivalent of 1000 watts
used for one hour.
Electricity Bills: TY#1: The flat rate remains the
same. A block rate varies depending on the time of day
and usage. TY#2: $1.30.
Energy Conservation Measures: TY#1: 1 boiler
; 2 steam; 3 turbine; 4 generator. TY#2: 1. They have
been formed from fossilised remains of prehistoric
plants. 2. Sulphur dioxide (SO2), nitrogen oxides (NOx),
ground-level ozone, particulate matter (PM), carbon
monoxide (CO), carbon dioxide (CO2), volatile organic
compounds (VOC) including benzene, some heavy
metals.
Different Bulbs: 1. bulb; 2. tungsten filament; 3.
support wires; 4. electrical foot contact; 5. glass mount;
6. inert gas..
Extinguishing Fires: Humans have a high level of
salt water in their body, which makes them very good
conductors of electricity. The rubber soles act as an
insulator.
Hazards and Electricity: Metal is a good
conductor of electricity. If this is conducted into people
it will cause an electric shock or electrocution.
Protective Gear: 1. Work boots protects against
electric shock, penetration of metals or stones etc, and
dropping objects onto the feet. Helmet protects against
head injury from falling objects or knocks on objects.
Goggles protect the eyes from foreign bodies and
pollutants. Gloves protect the hands from chemicals,
excessive heat or penetration from sharp objects. 2.
Advantages as above. Disadvantages: uncomfortable,
impairing vision or functionality, expense.
Different Types of Levers: TY#1: Increases
the force applied with less effort or multiplies the
effectiveness of a system. TY#2: Class 1 Levers: scissors,
see saw, pliers, hammer, crowbar. TY#3: Class 2
Levers: bottle opener, nutcracker, diving board,
wheelbarrow, spanner.
Simple Machines: 1. wheel and axle; 2. gears; 3.
inclined plane; 4. pulley. 2. The gears transfer energy
from a larger gear to a smaller one. The inclined plane
would be used to elevate objects. The pulley system
uses a system of wheels that transfers energy from a
pulling action, usually to elevate objects. The wheel and
axle allows the wheel to move and reduces friction.
Properties of Metals and Non-Metals: TY#1:
Pan: good heat conductors and high melting point;
Screwdriver: hard; Necklace: shiny; Plug: good
conductor of electricity though part of it is a bad
conductor as it is only the wires that conduct electricity.
TY#2: 1. The particles are packed in a uniform manner.
The layers are able to slide across each other. 2. It is
malleable, relatively cheap, easy to pull into a wire and
conducts electricity. 3. Carbon fibre and polymers.
Uses of Plastics: TY#1: Dustbins, safety helmets
and car seats – hardness and density. Cooking utensils
machine components – resistance to heat. Storage of
chemicals and food for example – organic solvents,
oxidation and ionizing radiation. Recycling plastics
and moulding into shapes for storage and toys –
melt upon heating. Cooking utensils – insulator of
heat. Insulation around wires and electrical devices
– insulator of electricity. TY#2: 1. Any three of the
following: hardness, insulator of heat and electricity,
density, and resistance to heat, organic solvents,
oxidation and ionizing radiation. In particular, most
plastics will melt upon heating 2. Insulation against
heat and electricity. 3. Plastics do not usually degrade
and so stay in the environment for hundreds of years.
Burning plastics causes air pollution. The manufacturing
process uses up oil and causes pollution.
Benefits of Alloys: 1. Lithium 2. It is not very
reactive, it is readily available so inexpensive 3.
Amalgam – dental fillings. Brass – hinges and electrical
plugs. Solder – joining metals.
Rusting: 1. A reaction with oxygen forming an oxide.
2. It can weaken the metal and looks unattractive. 3. A
coating of a metal oxide forming a layer of corrosion on
the metal.
Rate of Rusting: TY#1: A: No rusting. B: High.
C: Highest. D: No rusting. TY#2: 1. Air and water
are essential for the process of rusting. Dissolved
salts increase the rate of rusting. 2. Rusting requires
moisture.
Preventing Rusting: 1. It prevents oxygen
reacting with the metal. 2. It covers the metal in thin
layer of less reactive metals. 3. Galvanising is where
a layer of tin covers iron or steel. Tin is more reactive
so corrodes first. The tin is acting as a sacrificial metal.
Dipping the iron or steel into molten tin makes the tin
layer. Galvanised objects include doors, metal frames,
car parts, buckets and nails. Household appliances such
as washing machines also have galvanised parts.
Household Chemicals: 1. 1. corrosive; 2. explosive;
3. flammable; 4. irritant; 5. oxidising; 6. toxic. 2.
Water, bleach, detergents, cleaning products. 3. Most
chemicals are in a solution of water.
Classification of Acids, Bases and
Salts: TY#1: 1. Open answer. 2. Open answer. 3.
It contains carbon dioxide which is acidic when in
solution. TY#2: 1. The slaked lime is a base so acts as a
neutraliser. 2. Acetic acid 3. Baking soda or bleach.
Classification of Suspensions, Solutions and
Colloids Salts: 1. Juice and water, syrup and water.
2. A solution is a homogeneous mixture made from two
or more substances. A suspension is a mixture where
small particles of a substance are spread through a
liquid or a gas. The particles are likely to settle at the
bottom if the suspension is left. 3. Mayonnaise, milk,
whipped cream, gelatin, butter, coloured glass, paper,
jelly and plaster.
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Answers To Test Yourself Questions
Separation Techniques: TY#1: 1. The filtrate is
the clear liquid in the bottom of the flask. The residue
is the solid matter collected. 2. The particles in the
solution are too small and pass through the gaps in
the paper. TY#2: 1. The particles of salt are too large to
get caught. 2. It cools the water vapour and slows the
particle movement down. This condenses it into a liquid.
3. Different chromatograms can be identified by the Rf
(retardation factor or residue factor), which is basically
the distance travelled by the compound divided by the
distance travelled by the solvent.
Safe and Economic Use of Chemicals: 1. Keep
the chemicals out of reach. 2. To ensure that people do
not mistake them for other products.
Cleaning Products: 1. Drain cleaner and glass
cleaner. 2. They react with the metal and make it dull in
appearance. 3. Hydrogen peroxide or chlorine.
Hard and Soft Water: 1. Some people prefer the
taste. Calcium ions in the water are good for children’s
teeth and bones. 2. The dissolved salts and minerals
can be deposited on the heating elements. Calcium
carbonate or limescale is produced when the water is
heated. More energy is needed to heat the water, which
increases costs and breakdowns.
Section C
The Location of the Earth: From left to
right: Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus, Neptune.
Explain How Bodies Stay in Orbit: 1. Gravity. 2.
True. 3. Sun.
Physical and Chemical Properties of Soil: 1.
Top to bottom: humus, water, clay, silt, sand, gravel. 2.
Humus is formed when dead plants and animals decay.
3. Clay; sand and gravel; clay. 4. pH, colour.
Soil Erosion: Sheet erosion – Prevent water flowing
over the soil. Improve drainage. Maintain plant cover.
Mulch and ground cover. Rill erosion – Prevent flowing
water moving across the land. Improve drainage.
Contour drains. Gully erosion – Divert or modify water flow.
Construct a dam.
The Carbon, Water and Nitrogen
Cycles: Carbon: 1. combustion; 2. photosynthesis.
Nitrogen: 1. nitrogen; 2. roots; Water: evaporation.
Volcanic Eruptions: 1. Cinder cone volcanoes are
usually made of piles of lava and not ash. Cinders of
lava are blown into the air during eruptions and leave
broken fragments around the opening of the volcano
that forms a small, oval-shaped volcano. 2. Shield cone
volcanoes are usually found at constructive or tensional
boundaries. Eruptions tend to be frequent but relatively
gentle. They are low, with gently sloping sides. They are
formed by eruptions of thin, runny lava. 3. Composite
volcanoes are made up of alternating layers of lava
and ash. They are usually found at compressional
boundaries. Eruptions can be pyroclastic flow rather
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than a lava flow. A pyroclastic flow is a mixture of hot
steam, ash, rock and dust. It can move at high speeds,
with temperatures of 400°C.
Purifying Water:
Ocean water
STEP 1
Pre-treatment
STEP 2
Reverse osmosis
STEP 3
Conditioning+disinfection
Leftover high-salinity
water discharged
as brine
Filters remove suspended
solids and other particles
that would interfere with
the desalting process
Reverse osmosis membranes
separate dissolved minerals
(including salts) and other
impurities from the water
Mineral and/or chemicals are
added to ensure produced water
meets health, aesthetic and
anti-corrosion standards
Properties of Water: Solid, liquid, gas, plasma.
Types of Fossil Fuel: 1. They are the fossilised
remains of decomposed ancient matter. 2. Formed
millions of years ago from the remains of decayed
matter. 3. Top to bottom: coal, oil, gas.
Energy from Petroleum: The sun, by the process
of photosynthesis.
Alternative Sources of Energy: TY#1: Wind
and wave – kinetic energy moves a turbine, which
generates electricity. Biofuels –usually made from
plants that have just been harvested. There are
three main types: ethanol, biodiesel, and biojet fuel.
Geothermal – geothermal wells release greenhouse
gases trapped deep within the earth. Hydroelectric –
kinetic energy from the movement of water generates
electricity. TY#2: So they absorb as much sunlight as
possible.
Variables Affecting Solar and Wind
Energy: Sound, heat and kinetic.
Principles of Forces: The wing is a specific shape
called an aerofoil. The air flowing over the wing is
pushed down and forward. As Newton’s third law states,
the air exerts a force on the wings and the aeroplane
that is up and slightly backward.
You
Glossary
Glossary
Absorption The process where one
Blood The mixture of liquid and cells that
substance is taken up by another through tiny
pores or holes.
Acid Sharp-tasting, corrosive substances with a
pH lower than 7.
Active transport The process by which
molecules move across a cell membrane against a
concentration gradient. This requires energy.
Aerobic respiration The process that
releases energy from glucose in the presence of
oxygen.
Agglutination A process in which particles
in a liquid clump together.
Alloys A metal made by mixing two or more
metals.
Ammeter An instrument used for measuring
electric current.
Amperes/Amps The unit of electric current.
Anaerobic respiration The process that
releases energy from glucose without the need for
oxygen.
Artery A muscle-lined vessel that carries
blood from the heart to other parts of the body.
circulates in many animals to transport oxygen and
nutrients to cells and waste products away.
Breathing The process of taking air into and
out of the lungs.
Canine A pointed tooth next to the incisors
that is enlarged in carnivores.
Capillary One of the tiny branching blood
vessels that link arteries and veins.
Carnivore An animal that feeds on other
animals.
Cell (electrical) A device that produces and
electric current from chemical reactions.
Cell (biological) The smallest unit of living
things.
Cell membrane The membrane that forms
the outer surface of cells. The cell membrane
regulates the passage of materials into and out of
the cell.
Cell wall A rigid layer lying outside the cell
membrane of plants, fungi and bacteria.
Centre of gravity A point on which the
weight of a body or system may be considered to
be concentrated.
Chemical energy The energy stored in the
bonds of chemical compounds.
Chlorophyll A green pigment responsible for
the absorption of light in photosynthesis.
Chloroplast An organelle in green plants
containing chlorophyll.
Cilia Tiny hair-like structures.
Circulation The movement of blood around
the body, pumped by the heart.
Clones Identical cells produced from the same
cell.
Conductors Objects or materials that allow
the flow of electricity and/or heat.
Consumer Organisms that need to eat or
consume food as they cannot make their own.
Cross-pollination The transfer of pollen
from one plant to another.
Cytoplasm The jelly-like material within a
cell.
Artificial vegetative
propagation Where pieces of a parent plant
are removed and grown to form another plant or
plants.
Asexual reproduction A type of
reproduction where offspring are produced from
one individual parent.
Assimilation The absorption of nutrients
into the body.
Balanced diet A diet that contains a
healthy proportion of all of the food groups
(carbohydrates, fats, proteins, vitamins, minerals
and water).
Base A chemical compound that combines with
acids to form a salt and water.
Bimetallic strip A bar made up of two
different metals. When heated, the metals expand
at differing rates and the bar bends.
Binary fission A type of asexual
reproduction where cells grow and then split into
two clone cells.
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Decomposers Organisms that break down
Free electrons Electrons that are not
dead and decaying materials for food.
Dialysis The removal of certain substances
from blood using a machine instead of the kidneys.
Diet The types of foods that an animal
commonly eats.
Diffusion The movement of atoms or
molecules from an area of high concentration to
an area of low concentration.
Digestion The mechanical and chemical
breakdown of food molecules into smaller
molecules.
Effort The force needed by a machine to
achieve work.
Egestion The process of discharging
undigested food and waste from the body.
Electric current The flow of electric
charge.
Electrical energy Energy made available
by the flow of electric charge through a conductor.
Embryo A living organism in the early stages
of development.
Energy The capacity for doing work.
Environment The external surroundings,
both biotic and abiotic, that act on an organism or
population.
Erosion The wearing away of rocks and soil
through agents such as ice, water, wind and living
things.
Excretion The process of removing waste
materials from the body.
Fertilisation The fusion of male and female
gamete to produce a zygote.
Food chains A series of organisms each
dependent on the next as a source of energy and
nutrients.
Food group A collection of foods that share
the same nutritional properties.
Forces Interactions that can change the speed,
direction or shape of an object.
Force multiplier Simple machines that
reduce the effort needed to do work.
Fossil fuel A natural fuel, such as oil, coal and
gas, made from the remains of animals and plants.
attached to atoms and are free to move.
Friction The resistance caused by one
material rubbing against another.
Fulcrum The point around which a lever turns.
Fuel A chemical substance that can be burned
to produce energy.
Fuse A safety device consisting of a thin piece
of wire that will melt and break a circuit before
there are any other problems in the circuit.
Gametes The male and female sex cells.
Gases A substance with molecules that are
entirely free to move. Gases have no fixed shape.
Gaseous exchange The movement of
oxygen and carbon dioxide across a membrane in
opposite directions.
Generator A machine or device for changing
mechanical energy into electrical energy.
Gravity The force that attracts a body towards
the centre of the earth or towards any other body
having mass.
Heat energy A form of energy that passes
through materials by means of kinetic energy. Heat
energy moves from areas.
Heart A muscular organ that pumps blood to
help it circulate around the body.
Herbivores Animals that feeds on plants.
Host An animal or plant in which a parasite
lives.
Humus The organic component of soil. It is
made from decomposed plant and animal remains.
Hypermetropia A condition of the eye
where far objects are clear (in focus) and near
objects are not clear (out of focus).
Incisor A narrow edged tooth at the front of
the mouth adapted for cutting.
Insulators Materials that do not readily allow
the conduction of electricity, sound or heat.
Irritant A substance that causes soreness or
inflammation to the body.
Joints A structure where two or more parts of
the skeleton come together. Some allow bending
of the limbs.
Lamp A device for giving out light.
Glossary
Light energy Electromagnetic radiation that
Organelles Structures in eukaryotic cells, for
is sensed by the human eye.
Liquids A phase of matter between solid and
gas.
Load The overall force that a structure is
subjected to when supporting mass.
Loam Fertile soil. A mixture of organic matter,
clay, sand and silt.
Matter A physical substance which occupies
space and has mass.
example, the nucleus and mitochondria.
Osmoregulation The control of the water
content and concentration of salts.
Osmosis Movement of a solvent through
a semi-permeable membrane separating two
solutions of different concentrations.
Ova The mature reproductive cells of female
animals. The plural of ovum.
Ovulation Release of an ovum from the ovary.
Oxidation A chemical reaction resulting in the
loss of electrons.
Oxygen cycle The biogeochemical cycle
of oxygen in the atmosphere, biosphere and the
earth’s crust.
pH A logarithmic scale showing the acidity or
alkalinity of a solution.
Perennating The ability of organisms to
survive from one growing season to another.
Photosynthesis A chemical process where
green plants synthesise starch from carbon dioxide
and water in sunlight.
Phloem Tubes that transport dissolved foods
from the leaves to all parts of the plant.
Placenta The organ that attaches embryo to
the wall of the uterus.
Pollination Transfer of pollen from the
anther to the stigma.
Population Group of organisms of the same
species in a community.
Potential The possibility to develop into
something in the future.
Premolar Broad-ridged tooth in mammals.
Situated behind the canine teeth.
Producer An organism as the source of energy
in a food chain, for example a green plant.
Progesterone Hormone responsible for the
lining of the uterus in preparation for a fertilised
ovum.
Recycle Convert (waste) into reusable material.
Reduce To make smaller in amount or size or
use less.
Reduction A chemical reaction resulting in
the gain of electrons.
Mechanical advantage (Force
ratio) The ratio of the output force (load) of a
machine to the input force (effort).
Metallic bonding A chemical bond binding
together atoms of a solid metal or alloy.
Mitochondria A structure within the
cytoplasm of a cell that is responsible for aerobic
respiration.
Molar A broad-ridged tooth in adult mammals.
Momentum The product of a body’s mass and
velocity.
Muscles A tissue consisting of muscle fibres.
Movement or tension in the body is caused by
muscle contraction.
Myopia Short-sightedness cased by the
refraction of the lens.
Neutralisation The process of an acid
reacting with a base to form a salt and water.
Nitrogen cycle A series of processes
that interconverts nitrogen and its compounds
including nitrogen fixation and decomposition.
Nucleus (cell) Large body in cytoplasm of
plants and animals that contains genetic material
of DNA.
Nucleus (atom) The centre core of an atom
that contains most of its mass.
Nuclear energy Energy obtained as a result
of nuclear fission or fusion.
Oestrogen One of the female sex hormones
produced by the ovaries.
Ohm SI unit of electrical resistance.
Omnivore An animal that eats both animal
and plants.
Opaque A material or substance that cannot be
seen through.
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Renal failure A medical condition in which
Transparent A material that allows light to
the kidneys fail to adequately filter waste products
from the blood.
Reproduction The production of offspring
by a sexual or asexual process.
Resistance A measurement (in Ohms) of
the difficulty a power source has in forcing electric
current through an electrical circuit.
Resistor An electrical component that limits
or regulates the flow of electrical current in a
circuit.
Reuse Use again or more than once.
Rhesus factor An antigen found on the
surface of red blood cells (Rh positive, Rh+). Rh
negative (Rh−) do not have the antigen.
Saponification The production of soap
from fats and lye.
Self-pollination Transfer of pollen from
the anther to the stigma on the same plant.
Semiconductor A substance that has an
electrical conductivity between an insulator and a
conductor.
Skeleton A framework of bone, cartilage, or
other rigid material supporting or containing the
body of an animal or plant internally or externally.
Solar energy Electromagnetic energy from
the sun that can be used in processes to generate
heat or electricity.
Solids Not a liquid or gas with a firm, stable
shape.
Sound energy Produced when an object
vibrates and can be carried in waves through a
medium such as air.
Sperm Male sex cell.
States of matter One of four distinct
forms that matter takes on: solid, liquid, gas and
plasma.
Switch A device for making and breaking the
connection in an electric circuit.
Terrestrial On or relating to earth.
Testa Protective outer covering of a seed.
Transformer A device used to reduce or
increase the voltage of an alternating current.
Translucent A material that allows some
light to pass through but objects behind are not
seen clearly.
pass through so that objects behind can be seen
clearly.
Turbine A machine that uses the power of
a liquid or gas to move a wheel that generates
electricity.
Ultra-filtration The process of removing
small molecules from the blood within the kidneys.
Unicellular Having or consisting of a single
cell, for example, protozoans, certain algae and
spores etc.
Urea The major end product of nitrogen
excretion in mammals.
Urine An aqueous fluid produced by the
excretory organs in animals for the removal of
waste products.
Vaccination A biological preparation used to
improve immunity to a particular disease.
Vacuole A fluid-filled pocket in the cytoplasm
of animal and plant cells.
Vascular bundle A strand of primary
tissues found in the stem of a vascular plant and
consisting of xylem and phloem.
Vector An organism, often a biting insect or
tick, that transmits a disease or parasite from one
animal or plant to another.
Vein A tube which is part of the blood
circulation system that carries blood towards the
heart.
Ventilation The process or provision of
supplying a building with continuous fresh air.
Voltage A quantitative measure of the
potential difference in charge between two points
in an electrical field.
Water cycle A process that circulates water
throughout the earth and atmosphere through
evaporation, condensation, transpiration and
precipitation.
Watt The SI unit of power, equivalent to one
joule per second.
Weather front A boundary that separates
two masses of air at different densities.
Xylem Tubes that transport water and solutes
from the roots to the leaves.
Zygote A fertilised ovum (diploid cell), the
result of the fusion of two haploid gametes.