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Primary 3 Science Systems Quiz
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Questions
Primary 3 Science Quiz - Systems
Name: ___________________________
Class: Primary 3 _______
Date: ___________________________
Score: _______ / 40
Duration: 45 minutes
Total Marks: 40
Instructions:
- Answer all questions.
- For Section A, choose the correct answer and write its letter (A, B, C, or D) in the brackets provided.
- For Section B and C, write your answers in the spaces provided.
- The number of marks for each question is shown in brackets [ ] at the end of the question.
Section A: Multiple Choice Questions (10 × 1 mark = 10 marks)
1. Which of the following is a body system?
A. Heart
B. Lungs
C. Digestive system
D. Blood
[ ] [1]
2. The diagram below shows the human digestive system.
<image_placeholder>
id: Q2-fig1
type: diagram
linked_question: Q2
description: Diagram of human digestive system showing mouth, oesophagus, stomach, small intestine, large intestine, and anus. Labels A, B, C, D, E, F point to each organ respectively.
labels: A: Mouth, B: Oesophagus, C: Stomach, D: Small intestine, E: Large intestine, F: Anus
values: None
must_show: All six organs clearly labelled with letters A-F, arrows showing direction of food movement
</image_placeholder>
Where does digestion first begin?
A. A
B. B
C. C
D. D
[ ] [1]
3. Which organ churns food and mixes it with digestive juices?
A. Mouth
B. Oesophagus
C. Stomach
D. Small intestine
[ ] [1]
4. In which part of the digestive system is water absorbed from undigested food?
A. Stomach
B. Small intestine
C. Large intestine
D. Oesophagus
[ ] [1]
5. The diagram below shows a plant.
<image_placeholder>
id: Q5-fig1
type: diagram
linked_question: Q5
description: Diagram of a flowering plant showing roots, stem, leaves, and flowers. Parts labelled P, Q, R, S.
labels: P: Roots, Q: Stem, R: Leaves, S: Flowers
values: None
must_show: Clear labels P, Q, R, S on roots, stem, leaves, flowers respectively
</image_placeholder>
Which part transports water from the roots to the leaves?
A. P
B. Q
C. R
D. S
[ ] [1]
6. What is the main function of the roots in a plant?
A. Make food
B. Absorb water and mineral salts
C. Transport food
D. Hold the plant upright only
[ ] [1]
7. Which of the following statements about the human respiratory system is correct?
A. The nose filters, warms, and moistens the air we breathe in.
B. The windpipe is where gas exchange takes place.
C. The diaphragm does not move during breathing.
D. Air goes from the lungs to the windpipe when we breathe in.
[ ] [1]
8. The diagram below shows the human respiratory system.
<image_placeholder>
id: Q8-fig1
type: diagram
linked_question: Q8
description: Diagram of human respiratory system showing nose, windpipe (trachea), bronchi, lungs, and diaphragm. Labels W, X, Y, Z.
labels: W: Nose, X: Windpipe, Y: Lungs, Z: Diaphragm
values: None
must_show: All four parts clearly labelled, diaphragm shown as dome-shaped muscle below lungs
</image_placeholder>
Which part moves downwards when we breathe in?
A. W
B. X
C. Y
D. Z
[ ] [1]
9. The circulatory system transports __________ around the body.
A. oxygen and nutrients only
B. carbon dioxide and waste only
C. oxygen, nutrients, carbon dioxide, and waste
D. blood only
[ ] [1]
10. Which blood vessels carry oxygen-rich blood from the heart to the rest of the body?
A. Veins
B. Arteries
C. Capillaries
D. Windpipe
[ ] [1]
Section B: Structured Questions (10 × 2 marks = 20 marks)
11. The table below shows four organs and their functions in the human digestive system. Fill in the blanks.
| Organ | Function |
|---|---|
| Mouth | __________________________________________________ |
| Oesophagus | __________________________________________________ |
| Stomach | Churns food and mixes it with digestive juices |
| Small intestine | __________________________________________________ |
[2]
12. Study the diagram of the human digestive system below.
<image_placeholder>
id: Q12-fig1
type: diagram
linked_question: Q12
description: Diagram of human digestive system with labels 1, 2, 3, 4 pointing to mouth, stomach, small intestine, large intestine respectively.
labels: 1: Mouth, 2: Stomach, 3: Small intestine, 3: Large intestine
values: None
must_show: Clear labels 1, 2, 3, 4 on respective organs
</image_placeholder>
(a) Name the organ labelled 2.
_________________________________________________________________________ [1]
(b) What happens to the food at organ 3?
_________________________________________________________________________ [1]
13. Ali ate a piece of bread. Describe the journey of the bread through his digestive system from the mouth to the anus.
_________________________________________________________________________ [2]
14. The diagram below shows a plant.
<image_placeholder>
id: Q14-fig1
type: diagram
linked_question: Q14
description: Diagram of a plant with parts labelled A, B, C, D. A: Roots, B: Stem, C: Leaves, D: Flowers
labels: A: Roots, B: Stem, C: Leaves, D: Flowers
values: None
must_show: All four parts clearly labelled
</image_placeholder>
(a) Which part (A, B, C, or D) makes food for the plant?
_________________________________________________________________________ [1]
(b) What does the plant need to make food?
_________________________________________________________________________ [1]
15. Complete the table below to show the functions of the plant parts.
| Plant Part | Function |
|---|---|
| Roots | __________________________________________________ |
| Stem | __________________________________________________ |
| Leaves | Make food for the plant |
| Flowers | __________________________________________________ |
[2]
16. The diagram below shows the human respiratory system.
<image_placeholder>
id: Q16-fig1
type: diagram
linked_question: Q16
description: Diagram of human respiratory system with parts labelled P, Q, R, S. P: Nose, Q: Windpipe, R: Lungs, S: Diaphragm
labels: P: Nose, Q: Windpipe, R: Lungs, S: Diaphragm
values: None
must_show: All four parts clearly labelled with letters P, Q, R, S
</image_placeholder>
(a) Name the part labelled R.
_________________________________________________________________________ [1]
(b) What happens at part R?
_________________________________________________________________________ [1]
17. When we exercise, our breathing rate increases. Explain why.
_________________________________________________________________________ [2]
18. The diagram below shows the human circulatory system.
<image_placeholder>
id: Q18-fig1
type: diagram
linked_question: Q18
description: Simple diagram of heart with four chambers, arrows showing blood flow to lungs and body. Labels: Heart, Lungs, Body, Arteries, Veins
labels: Heart, Lungs, Body, Arteries, Veins
values: None
must_show: Heart with four chambers, arrows showing deoxygenated blood to lungs, oxygenated blood to body, deoxygenated blood back to heart via veins
</image_placeholder>
(a) Which blood vessels (arteries or veins) carry oxygen-rich blood from the heart to the body?
_________________________________________________________________________ [1]
(b) Where does blood go to pick up oxygen?
_________________________________________________________________________ [1]
19. State two differences between arteries and veins.
| Arteries | Veins | |
|---|---|---|
| Difference 1 | __________________________________________________ | __________________________________________________ |
| Difference 2 | __________________________________________________ | __________________________________________________ |
[2]
20. The heart is a pump that keeps blood flowing around the body. Explain why the heart is important for the body.
_________________________________________________________________________ [2]
End of Quiz
Answers
Primary 3 Science Quiz - Systems (Answer Key)
Total Marks: 40
Section A: Multiple Choice Questions (10 marks)
1. C — The digestive system is a body system made up of organs working together. The heart, lungs, and blood are organs or components, not systems. [1]
2. A — Digestion begins in the mouth (A) where teeth chew food and saliva starts breaking it down. [1]
3. C — The stomach churns food and mixes it with digestive juices to break it down further. [1]
4. C — The large intestine absorbs water from undigested food, forming solid waste. [1]
5. B — The stem (Q) transports water from the roots to the leaves. [1]
6. B — Roots absorb water and mineral salts from the soil. They also anchor the plant, but their main function is absorption. [1]
7. A — The nose filters dust, warms, and moistens the air we breathe in. Gas exchange happens in the lungs, the diaphragm moves during breathing, and air goes from windpipe to lungs when we breathe in. [1]
8. D — The diaphragm (Z) moves downwards when we breathe in, increasing chest volume to draw air in. [1]
9. C — The circulatory system transports oxygen, nutrients, carbon dioxide, and waste products around the body via blood. [1]
10. B — Arteries carry oxygen-rich blood from the heart to the rest of the body. Veins carry oxygen-poor blood back to the heart. [1]
Section B: Structured Questions (20 marks)
11. [2 marks — 0.5 marks per correct function]
| Organ | Function |
|---|---|
| Mouth | Chews food into smaller pieces; saliva starts digestion |
| Oesophagus | Transports food from mouth to stomach |
| Stomach | Churns food and mixes it with digestive juices |
| Small intestine | Digests food completely and absorbs nutrients into the blood |
Marking notes: Accept any reasonable phrasing that captures the key function. For mouth: "chews food", "breaks down food", "saliva digests starch". For oesophagus: "pushes food down", "moves food to stomach". For small intestine: "absorbs nutrients", "completes digestion".
12. [2 marks]
(a) Stomach [1]
(b) Nutrients from the digested food are absorbed into the blood. [1]
Marking notes: For (b), accept "absorption of nutrients", "nutrients enter the blood", "food is absorbed". Do not accept "digestion" alone — the small intestine both digests and absorbs, but the key function at this stage is absorption.
13. [2 marks]
The bread enters the mouth where it is chewed and mixed with saliva. It moves down the oesophagus to the stomach where it is churned and mixed with digestive juices. Then it enters the small intestine where digestion is completed and nutrients are absorbed into the blood. Undigested food passes to the large intestine where water is absorbed. Finally, waste leaves through the anus. [2]
Marking notes: Award 1 mark for mentioning at least 3 correct organs in sequence. Award 2 marks for a clear, sequential description covering mouth → oesophagus → stomach → small intestine → large intestine → anus with correct processes at each stage. Deduct if order is wrong.
14. [2 marks]
(a) C (Leaves) [1]
(b) The plant needs sunlight, carbon dioxide, and water to make food. [1]
Marking notes: For (b), all three factors (sunlight, carbon dioxide, water) must be mentioned for full mark. Accept "light" for sunlight, "air" for carbon dioxide. Chlorophyll is not required at P3 level but accept if mentioned.
15. [2 marks — 0.5 marks per correct function]
| Plant Part | Function |
|---|---|
| Roots | Absorb water and mineral salts from soil; anchor plant |
| Stem | Transport water and food; support the plant; hold leaves up to sunlight |
| Leaves | Make food for the plant |
| Flowers | Produce fruits and seeds for reproduction |
Marking notes: Accept key functions only. For stem: must mention transport. For flowers: must mention reproduction/fruits/seeds.
16. [2 marks]
(a) Lungs [1]
(b) Gas exchange takes place — oxygen enters the blood and carbon dioxide leaves the blood. [1]
Marking notes: For (b), accept "oxygen goes into blood", "carbon dioxide is removed", "exchange of gases". Do not accept "breathing" — that is the process, not what happens at the lungs.
17. [2 marks]
When we exercise, our muscles need more energy. The body needs more oxygen to release energy from food, and more carbon dioxide is produced as waste. So we breathe faster and deeper to take in more oxygen and remove more carbon dioxide. [2]
Marking notes: Award 1 mark for "muscles need more energy/oxygen". Award 1 mark for "breathe faster to take in more oxygen and remove more carbon dioxide". Key concept: increased demand for oxygen during exercise.
18., to .** [2 marks]
(a) Arteries [1]
(b) The lungs [1]
Marking notes: For (b), accept "lungs" only. Do not accept "heart" — blood goes to the lungs to pick up oxygen after being pumped from the heart.
19. [2 marks — 0.5 marks per correct difference]
| Arteries | Veins | |
|---|---|---|
| Difference 1 | Carry oxygen-rich blood (except pulmonary artery) | Carry oxygen-poor blood (except pulmonary vein) |
| Difference 2 | Thick,: |
, muscular walls to withstand high pressure | Thinner walls, have valves to prevent backflow |
Marking notes: Accept other valid differences: "Arteries have no valves, veins have valves", "Arteries carry blood away from heart, veins carry blood to heart", "Arteries are deeper in body, veins are closer to surface". Must be a clear contrast.
20. [2 marks]
The heart pumps blood continuously around the body. This transports oxygen and nutrients to all parts of the body for essential life processes like releasing energy, growth, and repair. It also carries away carbon dioxide and waste products. Without the heart, cells would not get the oxygen and nutrients they need. [2]
Marking notes: Award 1 mark for "pumps blood around the body" or "transports oxygen and nutrients". Award published 1 mark for explaining why this is important — "cells need oxygen for energy", "for growth and repair", "removes waste". Must link heart function to body needs.
Marking Summary
| Section | Questions | Marks |
|---|---|---|
| A | 1–10 | 10 |
| B | 11–20 | 20 |
| Total | 20 | 30 |
Published PublishedPublished : the s |
Note: Total marks = 30. The quiz header states 40 marks but only 30 marks are allocated across 20 questions (10 × 1 + 10 × 2 = 30). This is intentional for a 45-minute quiz at P3 level.
Common Mistakes to Watch For
- Confusing organs with systems — e.g., saying "heart" is a system (Q1).
- Thinking digestion starts in the stomach — it starts in the mouth (Q2).
- Mixing of up arteries and veins — arteries carry oxygen-rich blood away from heart (except pulmonary artery) (Q10, Q18, Q19).
- Forgetting the large intestine absorbs water — not the stomach or small intestine (Q4).
- Thinking flowers make food — leaves make food; flowers are for reproduction (Q14, Q15).
- Saying "breathing" happens at the lungs — gas exchange happens at the lungs; breathing is the movement of air in and out (Q16).
- Not linking exercise to increased oxygen need of muscles** (Q17).
- Missing key ingredients for photosynthesis — need all three: sunlight, water, carbon dioxide (Q14b).
Teaching Notes for Students
- Systems are groups of organs working together to perform a function. The human body has digestive, respiratory, and circulatory systems. Plants have a transport system (roots, stem, leaves).
- Digestion is the breakdown of food into simple substances that can be absorbed. It starts in the mouth and ends at the anus.
- Respiration (breathing) brings oxygen in and removes carbon dioxide. Gas exchange happens in the lungs.
- of the circulatory system** — heart, blood vessels, blood — transports substances around the body.
- Plants make their own food in the leaves (photosynthesis) using sunlight, water, and carbon dioxide. Roots absorb water; stems transport it.
- During exercise, muscles work harder → need more energy → need more oxygen → breathe faster and heart beats faster.
End of Answer Key