Cambridge IGCSE Biology 0610: Hormones, homeostasis and tropic responses (by subtopic) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover three subtopics of topic 14, Coordination and response, in the Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028: 14.3 Hormones, 14.4 Homeostasis and 14.5 Tropic responses. Questions and parts marked (Extended) test Supplement content, which only Extended candidates (Papers 2 and 4) need. Everything else is Core. Calculators may be used throughout.

For explanations, read the coordination and response study guide or the revision notes. Nerves, reflexes and the eye (14.1 and 14.2) are practised in the coordination and response practice questions. Course pages: Cambridge IGCSE Biology hub and printable checklist.

Questions

1. Describe what is meant by a hormone. [3]

2. An outline diagram of the human body shows four glands, labelled A to D.

• A: on top of each kidney.
• B: just below the stomach.
• C: in a female, one on each side of the uterus.
• D: in the scrotum of a male.

(a) Name each gland, A to D, and the hormone it secretes. [4] (b) (Extended) Gland B secretes a second hormone. Name it. [1]

3. A cyclist swerves to avoid a car that pulls out in front of her. Her adrenal glands secrete adrenaline.

(a) State the name given to situations like this, in which adrenaline is secreted. [1] (b) State three effects of adrenaline on her body. [3] (c) (Extended) Describe the role of adrenaline in the control of metabolic activity, and explain how this helps her muscles. [3]

4. The cyclist in Question 3 squeezed her brakes within a fraction of a second of seeing the car. Ten minutes later her heart was still beating fast. Use this example to compare nervous and hormonal control. [2]

5.

(a) Describe what is meant by homeostasis. [1] (b) State the effect of insulin on the blood glucose concentration. [1] (c) (Extended) The body has a set point for its core temperature. Explain the concept of homeostatic control by negative feedback, with reference to this set point. [3]

6. (Extended) Two adults, A and B, each drank the same glucose solution after fasting overnight.

Time after drink / min	0	30	60	90	120
A, glucose / mmol per dm³	4.4	7.7	6.6	5.3	4.5
B, glucose / mmol per dm³	6.4	10.8	13.2	14.4	14.2

(a) Calculate the percentage increase in person A’s blood glucose concentration between 0 and 30 minutes. Show your working. [2] (b) Describe how person A’s pancreas and liver return the blood glucose concentration towards normal between 30 and 120 minutes. [3] (c) Calculate the percentage increase in person B’s blood glucose concentration between 0 and 90 minutes. [2] (d) Person B has Type 1 diabetes and has not taken any treatment that morning. Explain why person B’s blood glucose concentration stays high. [1] (e) Outline the treatment of Type 1 diabetes. [3]

7. (Extended) Two hours into a marathon, a runner’s blood glucose concentration falls below its set point.

(a) Explain how the pancreas and liver bring the blood glucose concentration back up. [4] (b) Name one other hormone that increases the blood glucose concentration. [1]

8. (Extended) Identify each structure seen in a diagram of a section through human skin.

(a) A coiled tube deep in the skin, with a duct that opens onto the skin surface. [1] (b) A small muscle attached to the base of a hair. [1] (c) A layer of cells filled with lipid, below the deeper layer of the skin. [1] (d) Nerve endings that detect a rise or fall in temperature. [1] (e) Cells that carry impulses from these nerve endings to the central nervous system. [1] (f) Strands growing out of the skin that can be raised. [1] (g) Tubes that widen or narrow to change blood flow near the surface. [1]

9. (Extended) A cyclist rides hard for 1.5 hours on a hot day. Her body mass falls by 1.35 kg, almost all of it as sweat.

(a) Calculate her mean rate of mass loss in grams per minute. Show your working. [2] (b) Explain how sweating, and the arterioles supplying her skin surface capillaries, help to stop her body temperature rising. [4] (c) Later, in a cold wind, her core temperature starts to fall. Describe three ways her body responds. [3] (d) Describe the role of the brain in this control. [2]

10. A student placed five bean seedlings in a box lit through a slit on one side. After three days every shoot had bent towards the slit, by these angles from vertical: 34°, 29°, 38°, 31° and 28°.

(a) Name this response. [1] (b) Calculate the mean angle of bending. [1] (c) Describe a suitable control for this investigation. [1] (d) State two variables the student should keep the same. [2] (e) In a second investigation she laid germinating bean seeds on their sides on damp paper in the dark. Describe the direction in which the root and the shoot will grow. [2]

11. (Extended) A young shoot is lit from one side only.

(a) Explain how auxin causes the shoot to bend towards the light. [4] (b) In an investigation, 63% of the auxin collected below a shoot tip lit from one side came from the shaded side and 37% from the lit side. Calculate the ratio of auxin on the shaded side to auxin on the lit side. Give your answer to 2 significant figures. [1] (c) The shoot tip of a second seedling is cut off before it is lit from one side. Predict what happens to this shoot, and explain your prediction. [2] (d) Explain why phototropism and gravitropism of a shoot are examples of the chemical control of plant growth. [2]

Answers

1. A chemical substance produced by a gland [1], carried by the blood [1], which alters the activity of one or more specific target organs [1].

Examiner insight: The three marks match the three parts of the syllabus description; “a chemical messenger” alone earns at most one.

2. (a) A: adrenal gland, adrenaline [1]. B: pancreas, insulin [1]. C: ovary, oestrogen [1]. D: testis, testosterone [1].

(b) Glucagon [1].

Examiner insight: Each mark in (a) needs both gland and hormone correct; “glycogen” written for glucagon in (b) scores nothing.

3. (a) Fight or flight [1].

(b) Increased breathing rate [1]; increased heart rate [1]; increased pupil diameter (wider pupils) [1].

(c) Adrenaline increases the blood glucose concentration [1] and increases heart rate [1], so more glucose and oxygen are delivered to her muscles for (faster) respiration / energy release [1].

Examiner insight: “Effects on the heart” or “the eyes change” is too vague; each mark needs the direction of change (increased) and the specific feature, such as pupil diameter.

4. Nervous control is faster: the braking response started in a fraction of a second [1]. Hormonal control lasts longer: her heart rate was still raised ten minutes later [1].

Examiner insight: Each point must be comparative (“faster”, “longer lasting”) and about speed or duration, the only two features the syllabus asks for.

5. (a) The maintenance of a constant internal environment [1].

(b) Insulin decreases the blood glucose concentration [1].

(c) A rise above the set point is detected [1] and responses bring it back down; a fall below it is reversed in the same way [1]. The response always reverses (opposes) the change, which is why it is called negative feedback [1].

Examiner insight: Describing only the response to overheating, with no set point and no reversal of the change, usually scores one mark.

6. (a) (7.7 − 4.4) ÷ 4.4 × 100 [1] = 75% [1].

(b) The pancreas detects the rise and secretes insulin [1]. Insulin causes the liver to take up glucose [1] and convert it to glycogen, which is stored [1].

(c) (14.4 − 6.4) ÷ 6.4 × 100 [1] = 125% [1].

(d) Person B’s pancreas secretes little or no insulin, so the liver does not convert glucose to glycogen [1].

(e) Injections of insulin [1]; regular monitoring of the blood glucose concentration [1]; controlling the diet, especially carbohydrate intake, and planning exercise [1].

Examiner insight: In (a) and (c), divide by the starting value; dividing by the final value loses the method mark.

7. (a) The pancreas secretes glucagon [1], carried in the blood to the liver [1]. The liver converts glycogen into glucose [1] and releases it into the blood, so the concentration rises towards the set point [1].

(b) Adrenaline [1].

Examiner insight: “Glucagon is converted into glucose” loses the conversion mark; it is glycogen that the liver converts.

8. (a) Sweat gland [1].

(b) Hair erector muscle [1].

(c) Fatty tissue [1].

(d) Receptors (temperature receptors) [1].

(e) Sensory neurones [1].

(f) Hairs [1]. (g) Blood vessels (arterioles) [1].

Examiner insight: Use the syllabus names; “nerve” for (e) is not specific enough when the question asks which cells carry impulses to the central nervous system.

9. (a) 1.35 kg = 1350 g; 1.5 hours = 90 minutes [1]. 1350 ÷ 90 = 15 g per minute [1].

(b) Sweat glands release sweat onto the skin [1]; evaporation of sweat removes heat [1]. Arterioles supplying skin surface capillaries widen (vasodilation) [1], so more blood flows near the surface and more heat is lost [1].

(c) Any three of: vasoconstriction of arterioles, so less blood flows near the skin surface; shivering, as muscle contractions release heat from respiration; hair erector muscles contract so hairs trap insulating air; less sweat is secreted. One mark each [1] [1] [1].

(d) The brain receives impulses from temperature receptors and compares body temperature with the set point [1]; it sends impulses to effectors such as sweat glands, muscles and arterioles [1].

Examiner insight: Capillaries that “dilate” or “move nearer the surface” earn nothing; the marks are for arterioles widening or narrowing.

10. (a) Phototropism [1].

(b) (34 + 29 + 38 + 31 + 28) ÷ 5 = 32° [1].

(c) An identical set of seedlings given light from all sides (or evenly from above) [1].

(d) Any two of: temperature; volume of water; type and age of seedling; light intensity [1] [1].

(e) The root grows downwards, towards gravity [1]; the shoot grows upwards, away from gravity [1].

Examiner insight: “A box with no light” changes light intensity as well as direction, so it does not earn the control mark.

11. (a) Auxin is made in the shoot tip [1]. It diffuses through the plant from the tip [1]. More auxin collects on the shaded side than the lit side [1]. Auxin stimulates cell elongation, so cells on the shaded side elongate more and the shoot bends towards the light [1].

(b) 63 ÷ 37 = 1.7 (shaded : lit = 1.7 : 1) [1].

(c) The shoot does not bend (and grows very little) [1], because auxin is made in the shoot tip, so none is produced [1].

(d) The growth response is controlled by a chemical, auxin [1], which is unequally distributed in response to light or gravity, causing unequal cell elongation [1].

Examiner insight: In (a), “light destroys auxin” is not credited; the safe wording is that more auxin is found on the shaded side.

Where marks are usually lost

• Describing a hormone without all three parts: made by a gland, carried by the blood, acting on target organs.
• Comparing nervous and hormonal control on anything other than speed of action and duration of effect.
• Confusing glucagon with glycogen.

Next steps

• Practise nerves, reflexes and the eye with the 14.1 and 14.2 practice questions.
• Take the 0610 Core diagnostic or 0610 Extended diagnostic.
• Browse the Cambridge IGCSE Biology hub and tick off the printable checklist.
• Book a free trial class.

Official syllabus

Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028, topic 14 Coordination and response, subtopics 14.3 Hormones, 14.4 Homeostasis and 14.5 Tropic responses. Published by Cambridge University Press & Assessment.