Sample Quizzes For Preparation: The Circulatory System
AS Level Biology – The Circulatory System
Questions
1. What type of circulatory system do mammals possess?
A. Open single circulation
B. Open double circulation
C. Closed single circulation
D. Closed double circulation
2. Which blood vessel carries oxygenated blood from the lungs to the heart?
A. Pulmonary artery
B. Pulmonary vein
C. Vena cava
D. Aorta
3. Which statement is true about veins?
A. They have thick muscular walls
B. They carry blood away from the heart
C. They have valves to prevent backflow
D. They always carry oxygenated blood
4. What is the function of capillaries?
A. Pump blood
B. Exchange substances
C. Prevent backflow
D. Filter blood
5. Which blood vessel carries blood at the highest pressure?
A. Vein
B. Capillary
C. Artery
D. Venule
6. Which structure in the artery wall allows it to withstand high pressure?
A. Thin endothelium
B. Smooth muscle
C. Valves
D. Elastic fibres
7. Which of the following correctly matches a vessel with its function?
A. Pulmonary artery – carries oxygenated blood to body
B. Vena cava – carries oxygenated blood to heart
C. Aorta – carries oxygenated blood to body
D. Pulmonary vein – carries deoxygenated blood to lungs
8. What is a characteristic feature of capillaries?
A. Thick wall
B. Large lumen
C. One-cell-thick wall
D. Valves
9. Which of the following is not a type of white blood cell?
A. Lymphocyte
B. Neutrophil
C. Monocyte
D. Erythrocyte
10. Red blood cells are adapted for oxygen transport because they:
A. Have a large nucleus
B. Are spherical
C. Contain haemoglobin
D. Contain enzymes
11. What is the main function of lymphocytes?
A. Phagocytosis
B. Blood clotting
C. Antibody production
D. Oxygen transport
12. Which of the following cells has a multilobed nucleus?
A. Lymphocyte
B. Monocyte
C. Neutrophil
D. Red blood cell
13. Tissue fluid is formed at the capillary bed due to:
A. High osmotic pressure
B. Low hydrostatic pressure
C. High hydrostatic pressure
D. Presence of lymph
14. At the venous end of a capillary bed, fluid returns due to:
A. High hydrostatic pressure
B. Osmotic pressure
C. Capillary leakage
D. Pressure from lymph
15. Which statement about the pulmonary circulation is correct?
A. It supplies oxygen to body tissues
B. It removes urea from the kidneys
C. It sends blood to the lungs for gas exchange
D. It carries nutrients from intestines
16. What is the correct sequence of blood flow in systemic circulation?
A. Left ventricle → body → vena cava → right atrium
B. Right ventricle → lungs → pulmonary vein → left atrium
C. Aorta → lungs → heart → vena cava
D. Right atrium → lungs → left ventricle → aorta
17. Which vessel carries deoxygenated blood to the lungs?
A. Pulmonary vein
B. Pulmonary artery
C. Aorta
D. Vena cava
18. Which of the following best defines ‘closed circulatory system’?
A. Blood flows freely in body cavities
B. Blood is pumped by multiple hearts
C. Blood is confined to vessels
D. Blood is oxygenated at each organ
19. Which of the following is correct for capillary exchange?
A. Plasma proteins move out freely
B. Gases and nutrients diffuse across thin walls
C. Capillaries have valves
D. Blood pressure is higher than in arteries
20. Which component is absent from tissue fluid?
A. Glucose
B. Plasma proteins
C. Water
D. Oxygen
21. Which is the correct order of size (largest to smallest)?
A. Vein > artery > arteriole > capillary
B. Artery > vein > capillary > arteriole
C. Artery > arteriole > capillary > venule
D. Artery > vein > venule > capillary
22. Why do arteries have thicker walls than veins?
A. To carry more oxygen
B. To hold more blood
C. To resist high pressure
D. To accommodate valves
23. Which blood cell is responsible for phagocytosis?
A. Lymphocyte
B. Neutrophil
C. Platelet
D. Erythrocyte
24. What prevents backflow of blood in veins?
A. Muscular walls
B. Elastic recoil
C. Valves
D. Blood pressure
25. What is the key difference between plasma and tissue fluid?
A. Only plasma contains water
B. Only tissue fluid contains ions
C. Plasma contains proteins
D. Tissue fluid contains more COâ‚‚
26. Which property of water helps maintain body temperature?
A. Cohesion
B. High latent heat
C. High specific heat capacity
D. Solvent property
27. Which is not a function of the circulatory system?
A. Hormone transport
B. Gas exchange
C. Immune defence
D. Nutrient delivery
28. Which part of the heart receives blood from the body?
A. Right atrium
B. Left atrium
C. Right ventricle
D. Left ventricle
29. Which of the following best defines ‘haemoglobin’?
A. Hormone in blood
B. Enzyme for digestion
C. Protein carrying oxygen
D. Protein fighting infection
30. Which vessel contains the highest concentration of COâ‚‚?
A. Aorta
B. Pulmonary artery
C. Pulmonary vein
D. Hepatic vein
31. Why are valves not present in arteries?
A. Arteries are thin-walled
B. Arteries do not carry blood
C. Blood pressure is too low
D. Blood flows under high pressure
32. How are neutrophils identified microscopically?
A. Round nucleus
B. No nucleus
C. Multi-lobed nucleus
D. Kidney-shaped nucleus
33. How is the lymphatic system involved in circulation?
A. Forms blood cells
B. Pumps blood
C. Drains excess tissue fluid
D. Produces red blood cells
34. What makes capillaries ideal for diffusion?
A. Valves
B. High pressure
C. Thin walls
D. Large lumen
35. Which term best describes fluid formed from plasma filtering out of capillaries?
A. Lymph
B. Tissue fluid
C. Interstitial protein
D. Plasma
Marking Key and Explanations
1. D. Closed double circulation
- Mammals have a closed system (blood in vessels) and double circulation (pulmonary + systemic).
2. B. Pulmonary vein
- The only vein that carries oxygenated blood from the lungs to the left atrium.
3. C. They have valves to prevent backflow
- Valves maintain one-way flow in veins due to low pressure.
4. B. Exchange substances
- Capillaries are the site for exchange of gases, nutrients, and waste.
5. C. Artery
- Arteries carry blood away from the heart under high pressure.
6. D. Elastic fibres
- Elastic fibres stretch and recoil, maintaining high pressure in arteries.
7. C. Aorta – carries oxygenated blood to body
- Aorta distributes oxygen-rich blood from the left ventricle to the body.
8. C. One-cell-thick wall
- Capillary walls are one-cell thick to allow diffusion.
9. D. Erythrocyte
- Erythrocytes (red blood cells) are not WBCs; they transport oxygen.
10. C. Contain haemoglobin
- Haemoglobin binds oxygen in RBCs for efficient transport.
11. C. Antibody production
- Lymphocytes produce antibodies to fight specific pathogens.
12. C. Neutrophil
- Neutrophils have multi-lobed nuclei, aiding phagocytosis.
13. C. High hydrostatic pressure
- High pressure forces plasma out of capillaries to form tissue fluid.
14. B. Osmotic pressure
- At the venous end, osmotic pressure pulls water back in.
15. C. It sends blood to the lungs for gas exchange
- Pulmonary circulation sends deoxygenated blood to the lungs.
16. A. Left ventricle → body → vena cava → right atrium
- This describes the systemic circulation.
17. B. Pulmonary artery
- It carries deoxygenated blood to the lungs.
18. C. Blood is confined to vessels
- A closed system keeps blood inside vessels.
19. B. Gases and nutrients diffuse across thin walls
- Capillaries allow diffusion due to their thin walls.
20. B. Plasma proteins
- Proteins are too large to pass into tissue fluid.
21. C. Artery > arteriole > capillary > venule
- Correct descending size order of blood vessels.
22. C. To resist high pressure
- Arteries have thick walls to withstand high pressure from the heart.
23. B. Neutrophil
- Neutrophils are phagocytes that engulf pathogens.
24. C. Valves
- Veins contain valves to prevent backflow of blood.
25. C. Plasma contains proteins
- Plasma has plasma proteins; tissue fluid doesn’t.
26. C. High specific heat capacity
- Water absorbs large amounts of heat, helping regulate temperature.
27. B. Gas exchange
- Gas exchange occurs in lungs, not the circulatory system itself.
28. A. Right atrium
- It receives deoxygenated blood from the vena cava.
29. C. Protein carrying oxygen
- Haemoglobin is a protein that binds and transports oxygen.
30. B. Pulmonary artery
- It carries COâ‚‚-rich blood to the lungs.
31. D. Blood flows under high pressure
- Arteries don’t need valves due to high pressure flow.
32. C. Multi-lobed nucleus
- Neutrophils have segmented or multi-lobed nuclei.
33. C. Drains excess tissue fluid
- Lymphatics return tissue fluid to the circulatory system.
34. C. Thin walls
- One-cell-thick walls enable efficient diffusion.
35. B. Tissue fluid
- When plasma filters out of capillaries, it becomes tissue fluid.