Examination on Basic Science
Class: Primary 3
Term: Third Term
Time: 1 Hour
Total Marks: 70

SECTION A: OBJECTIVES (40 Marks)
Instruction: Answer all questions.

1. ________ is the ability of an object to stay up in the air. (a) Floatation (b) Sinking (c) Gravity
2. A stone will ________ when placed in water. (a) float (b) sink (c) stay
3. The main reason a balloon floats in air is because it is filled with ________. (a) heavy air (b) light gas (c) water
4. Which of these objects does NOT float on water? (a) Wood (b) Plastic bottle (c) Iron nail
5. The part of the human body responsible for thinking is the ________. (a) heart (b) brain (c) liver
6. An example of a harmful substance is ________. (a) water (b) alcohol (c) fruit
7. Which of the following body parts helps us to chew food? (a) Nostrils (b) Teeth (c) Ankle
8. ________ is a harmful substance found in cigarettes. (a) Water (b) Tobacco (c) Sugar
9. All of these are harmful substances except ________. (a) Alcohol (b) Cocaine (c) Clean water
10. Which of these is not a function of the human brain? (a) Thinking (b) Feeling (c) Pumping blood
11. Water that is unsafe to drink because it contains harmful substances is called ________ water. (a) clean (b) contaminated (c) boiled
12. Cholera is a disease caused by ________. (a) clean water (b) unsafe water (c) fresh air
13. The correct step in purifying water by boiling is to boil it for at least ________ minutes. (a) one (b) five (c) thirty
14. Adding ________ helps to settle dirt particles in water. (a) sand (b) alum (c) sugar
15. Which of the following parts of a plant absorbs water and nutrients from the soil? (a) Stem (b) Root (c) Leaf
16. All of these are functions of plant leaves except ________. (a) making food (b) absorbing sunlight (c) holding the plant upright
17. A seesaw is an example of a ________. (a) pulley (b) lever (c) wheel
18. Which of these simple machines helps to lift heavy loads using a rope over a wheel? (a) Lever (b) Pulley (c) Inclined plane
19. A hot air balloon uses the concept of ________ in air. (a) sinking (b) floatation (c) gravity
20. Which is NOT a method of purifying water? (a) Boiling (b) Filtering (c) Freezing

SECTION B: THEORY (30 Marks)
Instruction: Answer any THREE questions.

Question 1
(a) Define floatation in air. (2 marks)
(b) List two objects that can float on water and two that sink. (3 marks)
(c) State three dangers of taking harmful drugs like cocaine. (3 marks)
(d) Name one product that uses floatation in air. (2 marks)

Question 2
(a) Identify two parts of the human body and state one function for each. (2 marks)
(b) Explain briefly two methods of purifying water. (3 marks)
(c) Describe the importance of the brain in the human body. (3 marks)
(d) What is the purpose of adding alum to water during purification? (2 marks)

Question 3
(a) What is contaminated water? (2 marks)
(b) List three diseases that can be caused by drinking unsafe water. (3 marks)
(c) Explain the functions of the roots and leaves of a plant. (3 marks)
(d) Name two common contaminants found in water. (2 marks)

Question 4
(a) Define a lever as a simple machine. (2 marks)
(b) Give two examples of levers. (3 marks)
(c) Explain how pulleys help to lift heavy loads. (3 marks)
(d) State two reasons why people might take harmful substances. (2 marks)

Objective Marking Scheme

Question 1 – ✅ (a) Floatation
Question 2 – ✅ (b) sink
Question 3 – ✅ (b) light gas
Question 4 – ✅ (c) Iron nail
Question 5 – ✅ (b) brain
Question 6 – ✅ (b) alcohol
Question 7 – ✅ (b) Teeth
Question 8 – ✅ (b) Tobacco
Question 9 – ✅ (c) Clean water
Question 10 – ✅ (c) Pumping blood
Question 11 – ✅ (b) contaminated
Question 12 – ✅ (b) unsafe water
Question 13 – ✅ (b) five
Question 14 – ✅ (b) alum
Question 15 – ✅ (b) Root
Question 16 – ✅ (c) holding the plant upright
Question 17 – ✅ (b) lever
Question 18 – ✅ (b) Pulley
Question 19 – ✅ (b) floatation
Question 20 – ✅ (c) Freezing