2020
George Emmanuel
College
Form 1
Combined Science Notes
By Kwari C
C
[Type here]
FORM 1 COMBINED SCIENCE
SECTION
-
BIOLOGY
-
CHEMISTRY
-
PHYSICS
BIOLOGY:
1. Cells and levels of organization
2. Nutrition
3. Respiratory system
4. Transport systems
5. Reproduction in plants and animals
6. Health and diseases
LABORATORY RULES AND SAFETY
Syllabus objectives

explain laboratory rules

identify laboratory apparatus

demonstrate use of laboratory apparatus
What is combined science?
It is a compound subject made up of three broad sections namely physics, chemistry and biology.
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What is a scientist?
A person who investigates the world around him and try to discover things. A scientist uses his
senses and the brain to make observations, discoveries and gather information. He also uses
apparatus scientist carry out experiments in a special room called laboratory.
Laboratory safety
1. Do not eat in the laboratory
2. Do not taste anything in the laboratory unless you are told to do so.
3. Do not touch anything chemicals with bare hands.
4. Do not run in the lab
5. Do not make noise in the lab
6. Do not enter the lab without teachers permission
7. All accidents must be reported to the teacher immediately as well as unusual smells.
8. Understand all the instructions before carrying out an experiment
Laboratory apparatus
CELLS AND LEVELS OF ORGANIZATION
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Syllabus objectives
•
describe the structure of a plant and an animal cell
•
list similarities and differences between plant and animal cells
Biology
-Biology is the study of living organisms.
-All things are classified as living and non-living
Plant cell
Animal cell
What is a cell
It is the basic unit of all living things . Tissues are grouped together from organs and organs form
a system. Examples of systems are blood circulatory system, urinary system. Organs and organ
system together form an organism.
Structure of a plant cell
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Part
Function
Cell wall
A Gives cell the same rigid shape and
protects the cell
Cell membrane
Helps the substance move in and out
Cytoplasm
Thick jelly which contain the nucleus food
particles and some waste
Nucleus
Controls the activities of the cell
Permanent vacuole
Helps to stretch the cell
Chloroplast
Traps sunlight
Question
Differentiate a plant and an animal cell
Explain the functions of the following
1. Cell membrane
2. Cell wall
3. Vacuole
4. Chloroplast
5. Nucleus
Identify similarities between the plant and animal cell
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NUTRITION
Syllabus objectives

define balanced diet

list component of balanced diet

state functions of nutrients
Plant produce food using raw material obtained from the soil and air. The production of food in
plants only take place in the presence of sunlight (solar) energy by a process called photosynthesis.
The food made by plants contain chemical energy.
The word equation for photosynthesis
Water + carbon dioxide +sunlight →carbohydrates and oxygen
Other food nutrients produced by the plant proteins are proteins, fats, oils, mineral salts, vitamins,
roughage (fiber) including water
NB
Plants are they only organisms that can use solar energy to chemical energy plants are called
producers. Other organisms are consumers. Food chains is a linear feeding relationship.
Maize plant- cow –person and lion
Animal nutrition
Diet is the pattern of what one eats every day. Balanced diet is the diet that contains all nutrients
in their right amounts and proportions. Components of a balanced diet .A balanced diet is consist
of carbohydrates, fats, iron, vitamins, roughage
Carbohydrates
The word carbohydrate refers to a chemical compound that contain the elements carbon, hydrogen
and oxygen.
Functions of carbohydrates.
Carbohydrates give the body energy to do all the activities like walking, talking, thinking etc.
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Sources of carbohydrates
Proteins
Functions of proteins.
Are needed or building new tissues and for repairing the worn out tissues.
Sources of proteins
Sources of proteins are meat, milk and eggs
Fats
Functions of fats.
Provide more energy than carbohydrates.
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Sources of fats
Cooking oil, margarine, peanut butter and fatty meat.
Mineral salts
Mineral salts functions. Mineral salts are needed in smaller quantities . calcium and phosphorus
are used for bone and teeth formation.
Sources
Fish , eggs, dried vegetables, beans, meat and liver
Vitamins
They are needed in small quantities. They prevent certain diseases and malfunctions .
Sources
Fruits such as apples, pine apples, oranges etc
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Water
Functions
Makes up more than 70 percent of the body.
It enables all chemicals reactions to the place in the body.
It dissolves nutrients. It is used to make body fluids
Sources
Fiber or roughage
Functions
It is used to help proper functioning of digestive system. It helps smooth movement of food and
waste particles in the digestive tract.
Sources
Roughage are vegetables and fruits
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RESPIRATION
Syllabus objectives

State the percentage composition of air

Identify respiratory gases

describe the test for carbon dioxide gas

test for oxygen gas
Energy is that which makes the things move and happen.
The energy needed by animals to do all activities is obtained from food. After nutrients have been
absorbed they are transported in the blood to body cells where they are needed. In the cells nutrients
are further broken.
Energy nutrients (simple /glucose simple sugar molecules) are processed in the body cells by
oxygen obtained in the lungs through breathing. in the cells oxygen is used to burn oxidise sugar
(glucose) to release energy. The products of oxidation are carbon dioxide, water and energy. This
chemical process is called respiration
The word equation for respiration
Glucose+ oxygen →carbon dioxide + water +energy (heat)
Respiratory system
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Air is the mixture of gasses. Air is invisible. Air has mass and volume.
Inhailing – taking in air
Exhailing – taking out air
Composition of air
Gases present in air and their proportions
Gases in the air
Inhaled air
Exhaled air
Oxyen
20
16
Carbon dioxide
0,03
4
Nitrogen
78
78
Water vapour
Variable
Variable
Breathing movements Breathing out (exhailing ) .The chest cavity moves inwards and down wards
. the diaphragm moves upwards contracting expelling the air out. .Breathing in The chest cavity
moves outwards. The ribs move outwards and upwards the diagragm moves upwards flattering the
lungs expand taking in air
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Experiment
Aim
Oxygen test
Materials
Wooden splint, burner gas jar containing air
Method
1. Light the end of the glowing splint
2. Extinguish the flame so that the splint glow red.
3. Put the glowing wooden splint in gas jar A \
Observations
Record the observation
Conclusion
Experiment
Aim
To test for carbon dioxide
Materials
Lime water, bicarbonate indicator, straws, test tubes
Method
1. Pour a small amount ofg lime water or bicarbonate indicator into a test tube
2. Blow into the solution using a straw
Observations
Lime water
Clear - milky
Bicarbonate indicator
Red to yellow
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Conclusion ……Exhaled air has carbon dioxide
TRANSPORT SYSTEM
Syllabus objectives

describe water movement in plants

identify components of blood stating the functions of each component
In an organism there are vast numerous numbers of cells. These cells need special living transport
system to move various substances from place to place. Plant cells need carbon dioxide for
photosynthesis to manufacture carbon dioxide. Oxygen is needed for respiration.
Diffusion
Diffusion is the movement of particles from the region of higher concentration to the region of
lower concentration.
Osmosis
Is the movement of water molecules from the region of higher concentration to the region of lower
concentration through a partially permeable membrane
Outline the differences between diffusion and osmosis
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TRANSPORT SYSTEM IN ANIMALS
Syllabus objectives
• Identify components of blood stating the functions of each component
The body needs system to transport nutrients of the body.
Oxygen should be carried from the lungs to all cells for them to respire and release energy.
The transport system needs to remove waste materials e-g carbon dioxide , urine etc .Blood is a
component that is used to transport materials around the body.
The blood has four components these are plasma, red blood cells, white blood cells and Platelets
Red blood cells
Contain a substance called hemoglobin which blood its red color. The red blood cells absorb and
transport oxygen
White blood cells
These defend the body against diseases by killing germs. White blood cells are for defense
Platelets
Are small components which initiate blood clotting to stop excessive bleeding.
Plasma
A clear liquid which contains 92 percent water. It has dissolved nutrients, antibodies, and proteins.
It contains urea and carbon dioxide
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REPRODUCTION
Syllabus objectives

describe structure of a simple flower

describe pollination and fertilization

state signs of puberty
Reproduction
Refers to the increase in population of organisms of one type.
Reproduction is a process where young ones are produced by both plants and animals.
In plants the main functions of flowers is sexual reproduction
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1
2
3
4
5
Stigma
Style
Ovary
Ovule
Petals

Receives pollen grains during the process of pollination

Produces a sticky substance to ensure pollen grains get stuck

Supports the stigma

Provides pathway for pollen tube to the ovules

Produces ovules

Later develops into fruit after fertilisation

Are the female sex cells

Develops into a seed after the process of fertilisation

Attract insects for pollination by their bright colour and nice scent

Their shape promotes pollination as they direct insects towards the nectaries
6
Sepals

Protects the flower bud
7
Anther

Produces pollen grains
8
Pollen
grains

These are the male sex cells
Question
Outline the functions of the Parts of the flower
Fruit and seed dispersal
This is the scattering of fruits and seeds by
1. Animals
2. Water
3. Wind
4. Self explosive mechanism e-g the munondo seeds.
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Comparing wind pollinated and insect pollinated flower
Wind –pollinated flower dull
Insect pollinated flower
1. Are not small
Are usually large
2. Do not produce a scent nector
Produce a scent and nectar
3. Have long filament out of flower
Have short filament
4. Usually do not have petals
Have filaments that do not hang out
Questions
Explain the functions of the stigma, style, anther, filament
Identify the male sex cells and the female sex cells
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REPRODUCTION IN HUMANS
Syllabus objectives
•
state signs of puberty
Puberty or adolescence
Is the stage at which children become sexually mature. In girls /females puberty is attained at 910 yrs .
Sexual maturity in females
The girls internal reproductive organs change. The vagina becomes deeper. Vaginal discharge
occurs. The uterus become longer and the ovaries enlarge. Hips widen. Pubic hair grows and so
does the armpit. Breast become bigger.
Sexual maturity in males
Pubic hair grows as well as hair take place under the armpit. Body hair may also grow on the chest.
The voice breaks and the sound deeper. The penis becomes larger. Production of sperms begins.
The shoulder become broader. Beard grows. Wet dreams start wet dreams is the release of sperms
whilst asleep.
Adolescence is the difficult stage for most people. At this stage adolescence get bossy, aggressive,
shy, scared, outgoing to reserved. Sometimes teenagers become angry for nothing. Adolescence
want to become independent. Boys and girls start relationships.
Questions
1. Identify the similarities between the changes in girls and the changes in boys
2. Identify the differences between the changes in girls and the changes in boys
3. State any four pre-menstrual symptoms
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Male Reproductive System
Male and female sex cells
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Female Reproductive System
HEALTH AND DISEASES
Syllabus objectives

describe a healthy person

state importance of maintaining personal hygiene

list ways of disposing litter/ waste, stating their advantages and disadvantages

describe methods of transmission of diseases
Health is a state of physical mental and social well being. It does not simply mean the absence of
diseases.
Community health
Avoid of diseases by proper sanitation and good hygiene. Use toilets, latrines avoid bush system
Wash your hands each time you use the toilet. Drink clean water. put all waste in the bins and
rubbish pits. houses should be kept clean. all liter should be placed in bin
Individual / personal hygiene
1. our hands are the dirtiest parts of the body always wash your hands before handling food
and after using the toilet
2. wash your hands with warm soapy water before handling food and always after using the
toilets
3. the fingernail should be kept short
4. hair should be kept short and well combed.
5. underwear’s and shorts should be changed regularly and washed with soap and clean water
6. bath everyday and wear clean clothes
7. eat clean , warm or hot food
8. eat a balanced diet
9. relax and exercise regularly
10. get enough sleep of at least 8 hours
11. keep food covered
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Causes of diseases
Pathogens
A pathogen is a disease causing micro-organisms e-g bacteria, virus, fungi, protozoa. The
organisms are transmitted through air , water, food . a pathogen may stay on 1 part of the body can
the whole body.
Pathogen
Way of transmission
Disease
Virus
Air
Influenza , measles, small pox
Bacteria
Water
Cholera, typhoid
Bacteria
Air
TB leprosy
Fungi
Contact
Ring worm
Protozoa
Water
Dysentery
Worm
Water
Bilharzia
Chemicals and poisons
Smoke from factories, cigarettes, vehicle exhaust pollute the air. Factories produce poisons waste
which causes fish and people to die.
In the asbestos, cement and gypsum industries people get diseases like silicosis and asbestos which
affect lungs. Alcohol, drugs, marijuana, glue, heroine cause people to engage in fights
unreasonable arguments, stealing. Alcoholic suffer from liver and brain damage
There are also some diseases which are called deficiency diseases. Genetic defects are diseases
inherited from the parents such as dwarfism, albinism as well as down syndrome. Dwarfism –this
is when the limb and the bones. Albinism –lack of pigment, melanin in the skin. Down syndrome
–leads to mental retardation
Disease transmission
Is the spread of diseases? It can be by water, food, vectors, close contact and air
Water
Needed by all organisms makes about 70 percent of body. Pathogens spread through urine and
faeces. They are discharged into the water sources. Pathogens are also spread through dirty water
if used to clean clothes or wash utensils
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Food
As the house files walk on the faeces, hock and their sticky pads on its feet and its hairy body pick
up pathogens. These pathogens are then deposited on food when the houseflies settle on food. The
contamination of water and are cholera, dysentery and typhoid.
Close contact
Besides food and water, close contact can cause the spread of diseases. This happens mostly in
crowded places. Close contact can lead to spread of scabies. When people share bed linen. Skin
diseases are spread by skin to clothing to skin
Air
We need air to breathe in order to survive, but is the air that we breathe germs free. Air free can
also be a means to the spread of diseases. The pathogens are carried in the air and spread to the
other people. The method is called droplet infection. Tiny droplets containing germs may suffer
from diseases like cold, TB, influenza if the pathogens are present in the large enough amounts.
Leprosy is also transmitted by droplets infections
Vectors
Organism which transmit pathogens are called vectors. Examples are insects, rats and dogs.
Mosquitoes spread malaria and files spread diarrhea.
Prevention of spread of diseases
The spread of diseases can be prevented by proper sanitation and good hygiene. Instead of using
the bush system use toilets. Every time you use the toilet wash your hands with soap and clean
water
Symptoms of bilharzia
The symptoms of bilharzia are itchy skin, fever, blood stained urine, diarrhea,
Methods of preventing spread of bilharzia
1. Breaking the spread of bilharzia
2. Boiling drinking and washing water
3. Chlorination of water
4. Proper sanitation
5. Avoid playing in snail infested water
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6. Wearing protective boots
7. Building bridges over streams
8. Killing snails
Malaria
Malaria is a disease that is spread by female anopheles mosquito. Where do mosquito live in.
mosquitoes live in marshy areas, tall grass and dark corners
Transmission of malaria
When the mosquito bites a person they suck blood containing malaria parasite called plasmodium.
The plasmodium is a protozoa
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