Question Paper: Human Respiratory & Circulatory Systems | Class 5th

Total Marks: 50
Time: 1 Hour 30 Minutes

Instructions:

• Answer all questions in Sections A and B.

• Choose any two questions from Section C.

• Write neatly and use scientific terms where possible.

Marks Allocation:

• Section A: 1 mark per question (10 total).

• Section B: Marks as indicated per question (20 total).

• Section C: 5 marks per question (10 total, if two answered).

Section A: Multiple Choice Questions (10 Marks)

(Circle the correct answer)

1. Which organ filters dust from inhaled air?
   a) Lungs
   b) Nose
   c) Windpipe
   d) Diaphragm

2. Gas exchange in the lungs occurs in tiny sacs called:
   a) Bronchi
   b) Alveoli
   c) Capillaries
   d) Trachea

3. During inhalation, the diaphragm:
   a) Relaxes
   b) Contracts
   c) Disappears
   d) Stops moving

4. Which blood vessel carries oxygen-rich blood away from the heart?
   a) Vein
   b) Artery
   c) Capillary
   d) Vena Cava

5. The largest artery in the body is the:
   a) Pulmonary Artery
   b) Aorta
   c) Coronary Artery
   d) Jugular Vein

6. The heart chamber that pumps blood to the lungs is the:
   a) Left Atrium
   b) Left Ventricle
   c) Right Atrium
   d) Right Ventricle

7. Which component of blood fights infections?
   a) Red Blood Cells
   b) White Blood Cells
   c) Platelets
   d) Plasma

8. The “lub-dub” sound of the heart is caused by:
   a) Blood flow
   b) Valve closures
   c) Lung expansion
   d) Muscle stretching

9. Breathing through the nose is better than the mouth because the nose:
   a) Has no hairs
   b) Filters and warms air
   c) Absorbs oxygen faster
   d) Makes louder sounds

10. Which system works with the circulatory system to deliver oxygen?
    a) Digestive
    b) Respiratory
    c) Nervous
    d) Skeletal

Section B: Short Answer Questions (20 Marks)

11. Label the diagram of the heart (4 Marks)
    (Provide a diagram with blanks for: Right Atrium, Left Ventricle, Aorta, Pulmonary Artery)

12. Explain the difference between breathing and respiration. (3 Marks)

13. List the three types of blood vessels and one function of each. (3 Marks)

14. Describe what happens to the diaphragm and chest during inhalation. (2 Marks)

15. Why does the left ventricle have a thicker wall than the right ventricle? (2 Marks)

16. How do alveoli help in gas exchange? (3 Marks)

17. What is the role of platelets in the blood? (2 Marks)

18. Name two habits that can harm the respiratory system. (1 Mark)

Section C: Long Answer Questions (20 Marks)

19. Explain the pathway of blood through the heart, including chambers and major blood vessels involved. (5 Marks)

20. Compare arteries, veins, and capillaries in terms of structure and function. (5 Marks)

21. **Describe an experiment to measure pulse rate before and after exercise. Include:

    • Steps

    • Expected results

    • Why the pulse rate changes (5 Marks)**

22. How do the respiratory and circulatory systems work together to supply oxygen to the body? (5 Marks)

Bonus Question (Optional, +2 Marks)

Why do doctors use a stethoscope to listen to the heart and lungs?

End of Paper