IGCSE · Practice questions · Hormones

Slower, but longer.

Six original Cambridge-style questions on hormones and endocrine glands, the effects of adrenaline, heart-rate data and the comparison of nervous and hormonal control.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.

Keep these straight

Gland, blood, target.

Hormone: chemical, made by a gland, carried by the blood, alters specific target organs.
Pairs: adrenal glands and adrenaline, pancreas and insulin (and glucagon), testes and testosterone, ovaries and oestrogen.
Adrenaline: breathing rate up, heart rate up, pupils wider; (Extended) blood glucose up.
Nerves vs hormones: faster and shorter versus slower and longer-lasting.

Recall

[3 marks]

Define the term hormone.

A chemical substance produced by a gland. ✓
Carried by the blood. ✓
Which alters the activity of one or more specific target organs. ✓

Recall

[4 marks]

Name the hormone secreted by each of these glands: adrenal glands, pancreas, testes, ovaries.

Adrenal glands: adrenaline. ✓
Pancreas: insulin (Extended: also glucagon). ✓
Testes: testosterone. ✓
Ovaries: oestrogen. ✓

Explain

[4 marks]

A cyclist sees a car pull out in front of her. Describe three effects of the adrenaline secreted and explain how they help her react.

Adrenaline is secreted by the adrenal glands in a fight or flight situation. ✓
Heart rate increases, so blood carries oxygen and glucose to the muscles faster. ✓
Breathing rate increases, taking in more oxygen for respiration in the muscles. ✓
Pupil diameter increases, letting more light into the eyes. ✓

Data

[4 marks]

A student's heart rate was measured before and during a frightening film scene.

Time / min	0	1	2	3	6	10
Heart rate / beats per min	72	72	118	110	90	76

The scene began at 1 min and ended at 2 min. (a) Calculate the percentage increase in heart rate between 1 min and 2 min. (b) Use the data to explain why this response is thought to be hormonal, not only nervous.

(a) (118 − 72) ÷ 72 × 100 = 64% (63.9%). ✓
(b) Heart rate stayed high for several minutes after the scene ended. ✓
It took about 8 minutes to return close to the starting value. ✓
A long-lasting effect is typical of a hormone (adrenaline) carried in the blood; a purely nervous response would fade quickly. ✓

Analysis

[4 marks]

Compare nervous control and hormonal control in terms of speed of action and duration of effect, and explain the difference in speed.

Nervous control acts faster than hormonal control. ✓
The effect of nervous control is shorter-lived; the effect of hormonal control lasts longer. ✓
Impulses travel as electrical signals along neurones, which is very fast. ✓
Hormones must be carried in the blood to the target organ, which takes longer. ✓

Explain

[3 marks]

Extended. Describe the role of adrenaline in the control of metabolic activity.

Adrenaline increases the blood glucose concentration (the liver releases glucose into the blood). ✓
It increases the heart rate, so glucose and oxygen are delivered to the muscles faster. ✓
More respiration can take place in the muscles, releasing more energy for action. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.