Home / IB DP Biology C3.1 Integration of body systems-FA 2025- IB Style Questions For SL Paper 1

IB DP Biology C3.1 Integration of body systems-FA 2025- IB Style Questions For SL Paper 1

Question

What is a function of the pancreas?

A. To control the rate of metabolism by releasing thyroxine when metabolic rate is low

B. To release glucagon when blood glucose levels are low

C. To release insulin when blood glucose levels are low

D. To secrete an endopeptidase which lowers the blood glucose levels

▶️Answer/Explanation

Ans. B

Question

What distinguishes capillaries from other blood vessels?

A. They have valves which allow blood flow in one direction only.

B. They have a thin layer of muscle to help pump blood to the veins.

C. They have thin, permeable walls to allow exchange of materials between tissue and blood.

D. They have a thin layer of elastic fibre to resist changes in blood pressure.

▶️Answer/Explanation

Ans. C

Question

The diagram shows how heart sounds are aligned with the changes in blood pressure in the cardiac cycle.

What can be deduced about the cause of the heart sounds?

A. The 1st heart sound is caused by the closing of the atrio-ventricular valves

B. The 2nd heart sound is caused by the opening of the atrio-ventricular valves

C. The 1st heart sound is caused by the closing of the semi-lunar valves

D. The 2nd heart sound is caused by the closing of the atrio-ventricular valves.

▶️Answer/Explanation

Ans. A

Question

What is a function of luteinizing hormone (LH) in the female menstrual cycle?

A. To promote secondary sexual characteristics

B. To inhibit progesterone secretion

C. To stimulate the follicle to release estrogen

D. To trigger ovulation

▶️Answer/Explanation

Ans:D

Question

On the graph, which curve represents the change in FSH levels during the menstrual cycle?

▶️Answer/Explanation

Ans:D

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