YAAKA EXAMINATIONS

PRIMARY LEAVING EXAMINATIONS 2024

INTEGRATED SCIENCE

Time allowed: 2 hours 15 minutes

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Read the following instructions carefully :

1. Do not write your school or district name

anywhere on this paper.

• This paper has two sections: A and B.

Section A has 40 questions and section B has 15

questions. The paper has 15 printed papers

• Answer all questions. All the answers for both sections A and B must be shown in the spaces

• All working must be done using a blue or black ball point pen or ink. Any work done in pencil will NOT be marked except drawings and diagrams.
• Unnecessary changes in your work and handwriting that cannot easily be read may lead to

• Do not fill anything in the table indicated: ”For examiners’ use only” and the boxes inside the

Section A: (40 Questions)

1. Name the type of blood vessel that carries blood away from the heart.
   Answer: Artery
   Explanation: Arteries carry oxygenated blood away from the heart to the rest of the body.
2. What is the main function of the large intestine in the human digestive system?
   Answer: Absorption of water
   Explanation: The large intestine absorbs water and salts from the remaining indigestible food matter.
3. Name the gas that is necessary for combustion.
   Answer: Oxygen
   Explanation: Oxygen is needed for burning or combustion to occur.
4. State one reason why we boil drinking water.
   Answer: To kill germs
   Explanation: Boiling water kills harmful bacteria, viruses, and parasites, making it safe to drink.
5. What part of the plant is responsible for photosynthesis?
   Answer: Leaf
   Explanation: The leaf contains chlorophyll which captures sunlight for photosynthesis.
6. Name the type of soil that has the highest water retention capacity.
   Answer: Clay soil
   Explanation: Clay soil particles are very small and tightly packed, which allows it to retain water well.
7. Give one importance of the ozone layer to humans.
   Answer: Protects from harmful UV rays
   Explanation: The ozone layer absorbs most of the sun’s harmful ultraviolet radiation, protecting living organisms.
8. What is the primary source of energy for the earth?
   Answer: The Sun
   Explanation: The Sun provides the necessary light and heat energy that sustains life on Earth.
9. Which nutrient is essential for the formation of red blood cells?
   Answer: Iron
   Explanation: Iron is needed to produce hemoglobin, which is essential for carrying oxygen in red blood cells.
10. Name the process by which plants lose water through their leaves.
    Answer: Transpiration
    Explanation: Transpiration is the loss of water vapor from the aerial parts of a plant, primarily through stomata.
11. Which part of the human body is responsible for pumping blood?
    Answer: The heart
    Explanation: The heart pumps blood throughout the body, supplying oxygen and nutrients.
12. Name the instrument used to measure temperature.
    Answer: Thermometer
    Explanation: A thermometer measures temperature in degrees Celsius or Fahrenheit.
13. What is the main component of natural gas?
    Answer: Methane
    Explanation: Methane is the primary component of natural gas, used as a fuel.
14. State one way of conserving water in homes.
    Answer: Fixing leaking taps
    Explanation: Repairing leaks prevents water wastage.
15. Which organ in the body filters waste from the blood?
    Answer: Kidneys
    Explanation: The kidneys filter blood, removing waste products and excess water to form urine.
16. What is the function of the chloroplast in plant cells?
    Answer: Photosynthesis
    Explanation: Chloroplasts contain chlorophyll, which captures light energy for photosynthesis.
17. Name the process by which seeds are spread away from the parent plant.
    Answer: Seed dispersal
    Explanation: Dispersal helps reduce competition and increases the chance of survival for new plants.
18. Which part of the eye helps to focus light?
    Answer: Lens
    Explanation: The lens bends light rays to form a clear image on the retina.
19. What is the chemical formula of water?
    Answer: H₂O
    Explanation: Water is made up of two hydrogen atoms bonded to one oxygen atom.
20. Name the mineral necessary for strong bones and teeth.
    Answer: Calcium
    Explanation: Calcium is vital for bone and teeth strength and development.
21. Which sense organ helps us to hear?
    Answer: Ear
    Explanation: The ear detects sound waves and converts them into signals sent to the brain.
22. State one way in which plants help to reduce air pollution.
    Answer: Absorbing carbon dioxide
    Explanation: Plants take in carbon dioxide during photosynthesis, reducing atmospheric CO₂.
23. What is the boiling point of water at sea level?
    Answer: 100°C
    Explanation: At standard atmospheric pressure, water boils at 100°C.
24. Which gas is used by animals for respiration?
    Answer: Oxygen
    Explanation: Animals breathe in oxygen for cellular respiration, which releases energy from food.
25. Name the part of a plant that absorbs water and nutrients from the soil.
    Answer: Roots
    Explanation: Roots anchor the plant and absorb water and minerals from the soil.
26. What is the main function of the human skeletal system?
    Answer: Support and protection
    Explanation: The skeleton provides structural support and protects vital organs.
27. What is the term for animals that eat only plants?
    Answer: Herbivores
    Explanation: Herbivores feed exclusively on plant material.
28. Name the gas used in fire extinguishers.
    Answer: Carbon dioxide
    Explanation: Carbon dioxide displaces oxygen, helping to put out fires.
29. Which process involves the conversion of liquid water into vapor?
    Answer: Evaporation
    Explanation: Evaporation occurs when water molecules gain enough energy to become gas.
30. Name the process by which green plants make their own food.
    Answer: Photosynthesis
    Explanation: Photosynthesis converts light energy, water, and carbon dioxide into glucose.
31. State one way in which farmers can control pests in crops without using chemicals.
    Answer: Crop rotation
    Explanation: Crop rotation disrupts pest life cycles and helps prevent infestations.
32. Which type of simple machine is a seesaw?
    Answer: Lever
    Explanation: A seesaw functions as a lever, with the fulcrum at the center.
33. Name the gas that causes the greenhouse effect.
    Answer: Carbon dioxide
    Explanation: Carbon dioxide traps heat in the atmosphere, contributing to global warming.
34. What is the main source of dietary fiber?
    Answer: Plant foods, such as fruits and vegetables
    Explanation: Dietary fiber is found in plant cell walls and aids in digestion.
35. Which sense organ detects taste?
    Answer: Tongue
    Explanation: The tongue has taste buds that detect different flavors.
36. Name the part of a flower that produces pollen.
    Answer: Anther
    Explanation: The anther is the part of the stamen that releases pollen.
37. Which disease is caused by a lack of vitamin C?
    Answer: Scurvy
    Explanation: Scurvy causes symptoms like bleeding gums due to vitamin C deficiency.
38. What is the function of the respiratory system?
    Answer: To exchange gases
    Explanation: The respiratory system facilitates the intake of oxygen and expulsion of carbon dioxide.
39. Which tool is used to measure force?
    Answer: Spring balance
    Explanation: A spring balance measures the force applied to it using a calibrated spring.
40. Name the organ that controls body temperature.
    Answer: Hypothalamus
    Explanation: The hypothalamus regulates body temperature through feedback mechanisms.

Section B: (15 Questions)

41. (a) Name two types of simple machines found at home.
    (i) Pulley
    (ii) Lever
    (b) Explain how a lever makes work easier.
    Answer: A lever reduces the amount of force needed by increasing the distance over which the force is applied.
    (c) Draw and label a diagram of a wheelbarrow as a lever.
    Explanation: Simple machines make work easier by reducing the effort needed to perform a task.
42. The diagram below shows parts of a human digestive system. Name parts C and E.
    

Answer: C: Stomach, E: Small intestine
Explanation: The stomach stores and breaks down food, while the small intestine absorbs nutrients.
(Diagram: Digestive system with parts labeled.)

43. (a) State any two methods of food preservation.
    (i) Drying
    (ii) Freezing
    (b) Explain why food preservation is important.
    Answer: Preservation prevents spoilage and prolongs the shelf life of food.
    Explanation: Preserving food helps prevent the growth of microorganisms that cause spoilage.
44. The diagram below shows a simple electric circuit. Label the components.
    

Answer: Battery, bulb, wires, switch
Explanation: The circuit allows current to flow from the battery through the bulb, lighting it up.

45. (a) State any two effects of heat gain on matter.
    (i) Expansion
    (ii) Change of state
    (b) Explain why a metal expands when heated.
    Answer: Heat causes particles to move faster and spread apart.
    Explanation: Increased kinetic energy causes atoms in a solid to vibrate more, expanding the material.
46. The diagram below shows an experiment on rusting. What conditions are needed for rusting?
    

Answer: Water and oxygen
Explanation: Rusting occurs when iron reacts with water and oxygen to form iron oxide.
(Diagram: Iron nails in different conditions with labels.)

47. (a) Describe one way of preventing malaria.
    Answer: Using mosquito nets
    Explanation: Mosquito nets prevent bites from malaria-carrying mosquitoes.
    (b) Explain the role of vaccines in disease prevention.
    Answer: Vaccines stimulate the immune system to recognize and fight pathogens.
48. Explain the role of the kidney in excretion.
    Answer: The kidney filters waste from the blood, forming urine.
    Explanation: It removes urea, excess salts, and water from the bloodstream.
49. (a). Name the parts of the flower shown in the diagram.
    

Answer: Petal, stigma, anther
Explanation: The stigma receives pollen, the anther produces pollen, and petals attract pollinators.
(Diagram: Labeled flower.)

50. (a) State one way in which cattle farming contributes to the development of the leather industry.
    Answer: Provides raw hides and skins.
    (b) Name another industry that uses cattle products.
    Answer: Dairy industry
    Explanation: Cattle provide raw materials like hides, milk, and meat for various industries.
51. The diagram below shows an arrangement of teeth. Identify the types of teeth labeled D, C, and A.
    

Answer: D: Incisors, C: Canines, A: Molars
Explanation: Incisors cut food, canines tear it, and molars grind it down.
(Diagram: Labeled human teeth.)

52. Describe the process of photosynthesis.
    Answer: Photosynthesis is the process by which green plants make food using sunlight, carbon dioxide, and water.
    Explanation: The chloroplasts in plant cells capture sunlight, which is used to convert carbon dioxide and water into glucose.
53. Name the parts of the human respiratory system labeled in the diagram.
    

Answer: A: Trachea, B: Bronchus
Explanation: The trachea carries air to the lungs, where gas exchange occurs.
(Diagram: Labeled respiratory system.)

54. (a) State one way to prevent soil erosion on farmlands.
    Answer: Planting cover crops
    (b) Why is it important to prevent soil erosion?
    Answer: To maintain soil fertility and prevent land degradation.
    Explanation: Erosion removes the top layer of soil, which is rich in nutrients.
55. Explain the importance of the water cycle to living organisms.
    Answer: The water cycle provides fresh water to ecosystems, which is essential for all life.
    Explanation: Processes like evaporation, condensation, and precipitation replenish water sources.