Download SCIENCE ANSWER SHEET 1. C -Veins carry blood towards the

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SCIENCE ANSWER SHEET
C -Veins carry blood towards the heart. Blood moving in veins flows under low pressure. Veins
have thin walls and wide lumen that reduces the pressure of blood while flowing.
C-The diagram shows a flower. The flower is the reproductive part of a plant. The part marked X
represents the anthers. The development of ovules into seeds will not take place because self
pollination and fertilization won’t take place.
D-Foods are grouped into 3 main groups namely; Energy giving foods also known as
carbohydrates. They provide the body with energy for working and playing e.g. cassava, rice,
wheat, maize, potatoes, green bananas, fats and oils. Body building foods are also known as
proteins. They build and repair worn out body tissues e.g. meat, pork mutton, milk, eggs, beans,
peas, groundnuts. Protective foods are also called vitamins. They are used to protect the body
against diseases. Majorly are fruits and vegetables.
C-The diagram shown is a mammalian heart. The parts marked H and F are all arteries. Part H
is a pulmonary artery while F is an aorta. Blood flows in them under high pressure because they
thick elastic walls and narrow lumen.
B-The act of domesticated animals obtaining their feeds is known as grazing. The methods of
grazing animals are: a) Rotational grazing which includes strip grazing, tethering and
paddocking. Stall feeding is a method of controlled grazing, also known as zero grazing.
B-Drug abuse is the excessive use of drugs and depending on them therefore leading to
addiction. Health effects caused by drug abuse are; poor health, fits, lack of concentration,
withdrawal, addiction, impaired judgment, loss of consciousness, coma and death.
B-Water is lost in the soil through evaporation. Evaporation is the process by which liquid
changes into gaseous state. Water changes into water vapor.
C-Hydrophytes are plants which are adapted to grow in wet areas. They have developed special
features to combat their major problems of excessive water in the environment. They include;
water lettuce, duck weed, arrowroot and moss. Waves make hyacinth for example, unable to float
on water.
9. A-Air is a mixture of gases. From the chart S is Nitrogen gas (78%), Q is inert gases (0.97%),T
is carbon dioxide (0.03%). Carbon dioxide is used in fire extinguishers, photosynthesis,
preserving soft drinks and baking cakes.
10. D-Plants are classified into green plants and non-green plants, flowering and non-flowering.
Flowering plants are classified into monocotyledonous and dicotyledonous plants. Plants X, Y, Z
are algae, moss and hibiscus respectively.
11. B-Special groups are people with special nutritional requirements. Examples are infants,
lactating mothers(nursing mothers), expectant mothers, invalids(sick), convalescents(person
recovering from illness). The first breast milk from the mother soon after giving birth is known as
colostrum. It is thick and yellowish in colour. The main function of colostrums is to boost the
baby’s immunity.
12. D-Oxygen is part of a mixture of gases. It is used for burning, breathing, germination and
rusting. Carbondioxide is used during photosynthesis.
13. C-Energy transformation means energy conversion or changing from one form to another.
Energy transformation in a radio using dry cells produces chemical energy-radio circuit
produces electrical energy-speakers produces magnetic energy-speaker produces kinetic
energy-speaker produces sound energy.
14. C-A maize grain is an example of a monocot seed. The embryo consists of the plumule, part
marked B, and radical which is marked C. The plumule grows to form the shoot while the radical
grows to form the roots.
15. D-Clouds are classified according to their: appearance, shape and height. There are four types
of clouds: nimbus, stratus, cumulus and cirrusNimbus is dark-grey in colour and brings rain.
Cumulus indicates fine weather. Cirrus are found high above the sky and are white, thin and
feather-like.
16. B-Food chains are relationship of living organisms where one organism feed on the one that
feeds on another. From the food chain when all snakes are killed the Secretary birds would die of
starvation.
17. A-Tin snip is a second class lever. The load is usually in between the effort and fulcrum. It
belongs in the same group with a nutcracker, wheelbarrow, foot and door hinges.
18. D-The path followed by electricity is known as an electric circuit. The electrical path is made up
of: a source of electricity, a bulb, connectivity wires and switch. When the switch is closed, the
lamps will light.
19. B-Biogas is a type of energy that can be renewed. Examples of renewable sources of energy
are; solar, wind, biogas, waterfall etc. Examples of non-renewable sources are kerosene, petrol,
diesel and coal.
20. B-Immunization is the process of giving special drugs to healthy people to protect them from
being infected by certain diseases. The drug is called vaccine. Giving a vaccine is called
vaccination or immunization. Examples of immunisable diseases are T.B, measles,
poliomyelitis, Diphtheria, pertusis, Tetanus.
21. C-The beak drawn belongs to a flesh feeder. Feeders are birds that feed on flesh. They are
also called birds of prey. They have beaks which are sharp, hooked and strong.
22. A-A fish is an animal that moves by swimming, it has a streamlined body that allows for easy
movement in water.
23. A-A drug abuse is the excessive use of drugs and depending on them therefore leading to
addiction. Both legal and illegal drugs are abused. Illegal are commonly called narcotics drugs.
They include cocaine, bhang, heroin, mandrax.
24. B –A spoon belongs to the second class levers. These are levers with load as the centre that is,
load is between effort and fulcrum.
25. C-Light has 3 main properties namely: Light travels on a straight line, light can be reflected and
light can be refracted. From the experiment below when the cards are arranged on a straight
line, the viewer is able to see the light from the candle. It shows that light travels on a straight
line.
26. B-Excretory system deals with the removal of waste products from the body. Excretory organs
are skin, kidney and lungs. Lungs remove the following wastes: carbon dioxide excess and
water.
27. C-Malaria is spread from one person to another by the female anopheles mosquitoes. Ways of
preventing malaria are: sleeping under a treated mosquito net, draining stagnant water, taking
anti-malarial drugs. Treating drinking water is not a way of preventing Malaria.
28. B- One easily slides on a smooth surface because making a surface smooth reduces friction.
This means there is reduced opposing forces between the person and the surface.
29. A-Environment is the surrounding of a living thing. Air is a mixture of gases. Air is found
everywhere in all the components of environment.
30. B-Some industries release poisonous gases like sulphur dioxide and carbon dioxide which
dissolve in water and end up forming acid rain. Acid rain pollutes water.
31. B-Capillarity is the process by which water rises in soil. It is the process by which underground
water reaches the top soil.
32. C-Fertilization is the fusion of the male and female gametes to form a zygote. An Embryo
develops to become a foetus after 6-8 weeks. The foetus develops and at birth it is called a
newborn baby. The stages of development after fertilization are: zygote-embryo-foetus-baby.
33. B-Water conservation means to protect, preserve in good condition for future use. The following
are ways we conserve water; harvesting rain water, recycling water, re-using water, mulching
and shading. Overhead irrigation does not help to conserve water because water is sprinkled
anywhere hence a waste.
34. B-Environment is the surrounding of a living thing. Major components of the environment are
plants, water, air, soil and animals.
35. A-The diagram shown is a bottle opener. It’s a lever. A lever is a simple machine that has
effort(E), fulcrum(F) and load(R). It belongs to the 1st class levers. These are levers with their
turning points or fulcrum at the centre. The examples of 1st class are crowbar, claw hammer and
lid opener. F-fulcrum, R-load, E- effort.
36. A- A wind vane is used to show the direction of wind. The tail points where the wind is blowing
to while the arrow points where the wind is blowing from. If the tail is pointing east the wind is
blowing from west to east.
37. D- Roughages are also called fibre. Fruits and vegetables are important sources of roughages.
They have no nutritive value but assist in egestion.
38. D-Matter exists in three forms; solid, liquid and gases. Characteristics of liquids are; have
definite volume, definite mass and has no definite shape. Liquids therefore have no definite
shape.
39. C-Hard water does not lather easily with soap. It contains mineral salts. The minerals cause
hardness. Deposit of scales on sufuria and boilers makes them look dirty. Scales formed on hot
water pipes may cause blockage or clogging of pipes over a long period of time. Scum is the
substance that is formed on water pipes by hard water.
40. D-Bilharzia is a disease caused by bilharzia flukes. It affects the bladder and intestines. Its
symptoms are fever, blood in stool and urine, skin rash, coughing may also develop. Chronic
diarrhea is not a symptom of Bilharzia.
41. C- The diagram shows a beam balance. Pupils were using it to find the heaviness of an object.
It is used to the measure mass of objects.
42. B-Weeds are plants that grow in an unwanted area. Wandering jew has the following
characteristics. It has blue or purple flowers, grows along the ground, doesn’t easily dry, keeps
branching in different directions and has succulent fruits.
43. D-Adolescence is stage where one changes from childhood to adulthood. Physical changes are
changes that are visible and can be seen. In boys shoulders broaden, voice breaks, pubic hair
grows. In girls hips broaden and breasts enlarge. Showing moodiness is an emotional change
caused by hormonal imbalance.
44. B-Oesophagus is part of the digestive system. It is also known as the gullet or food pipe. The
diaphragm, bronchi, trachea are parts of the breathing system.
45. B-The diagram shows a female reproductive system. The part marked D is the uterine wall.
This is where implantation takes place. Implantation is the attachment of the zygote to the wall
of the uterus.
46. C-Immunization is the process of giving special drugs to healthy people to protect them from
being infected by certain disease. The drug is called a vaccine. Polio vaccine is given orally.
Injection is not used. Malaria, BCG and Typhoid are administered through an injection.
47. C-Hard water is water that does not lather easily with soap. It contains minerals. Boiling water
can make hard water to be soft water.
48. B-Tobacco can be taken through smoking, chewing, sniffing. When you burn tobacco three
substances are produced. Tar which causes cancer of the mouth, lips and lungs. Tobacco also
contains carbon monoxide which destroys the haemoglobin. Nicotine in tobacco causes
addiction.
49. A-Mass is the quantity of matter in a substance. Mass cannot change in an object. Weight,
volume and density of an object can change.
50. A-The diagram shows a fish. A fish is a vertebrate. It breathes through gills and has fins that
help in movement. The fins labeled A, B, C, D are: A –Pectoral, B-Caudal, C-Pelvic and D-Anal
fin.