IGCSE Biology: Coordination and response — Practice Questions (Cambridge 0610)

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 — Cambridge International holds copyright in its own papers. Use these alongside the official past papers available from your board.

Each question practises a skill tested in the June 2024 Paper 42. After each answer there is an examiner insight, a mark-scheme insight or a tip, and (where a close match exists) the real question to try next. Questions marked (Extended) test Supplement content.

Tier note: questions marked (Extended) go beyond 0610 Core: events at a synapse (14.1), accommodation, and rods, cones and the fovea (14.2). All other questions are answerable by a 0610 Core candidate.

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Questions

1. The tongue and the skin are both sense organs. Define the term sense organ. [2]

2. A cook touches a hot oven tray and immediately pulls her hand away before she feels any pain.

(a) Name the type of neurone that carries impulses from the receptors in her skin to the spinal cord.

(b) Name the type of neurone that carries impulses from the spinal cord to the effector.

(c) Name the effector in this response. [3]

3. (Extended) An impulse arrives at the end of one neurone, where it meets the next neurone at a synapse. Describe the events at the synapse that lead to an impulse being generated in the next neurone. [4]

4. (Extended) A cyclist looks up at a road sign far ahead, then looks down at a map clipped to her handlebars. Describe and explain the changes in her eye that bring the map into focus. [4]

5. (Extended) Give the position of rods and of cones in the retina, and what each type of cell does. [4]

6. A man walks out of a dark cinema into bright afternoon sunshine.

(a) State what happens to the size of his pupils.

(b) Explain why this response is useful.

(c) State why this response is described as a reflex. [3]

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Answers

1. A group of receptor cells [1] that respond to a specific stimulus such as light, sound, touch, temperature or chemicals [1].

Examiner insight (Cambridge 0610 June 2024 examiner report, Paper 42, Question 2(a)): Fewer candidates gained the mark for receptors than the mark for detecting stimuli. Include both parts: what a sense organ is made of and what it does.

Source for the examiner insights on this page: Cambridge IGCSE Biology 0610 June 2024 Principal Examiner Report for Teachers, Paper 0610/42 section, paraphrased.

Try the real question next: Cambridge IGCSE Biology 0610, June 2024, Paper 42, Question 2(a).

2. (a) Sensory neurone [1].

(b) Motor neurone [1].

(c) A muscle in her arm (which contracts to pull the hand away) [1].

Tip: work out which way the impulse travels before naming the neurone: sensory neurones carry impulses towards the brain or spinal cord, and motor neurones carry them away to an effector.

Try the real question next: Cambridge IGCSE Biology 0610, June 2024, Paper 42, Question 2(b)(i).

3. (Extended) The impulse causes vesicles to release neurotransmitter molecules [1] into the synaptic gap [1]. The neurotransmitter diffuses across the gap [1] and binds to receptor proteins on the membrane of the next neurone, which stimulates a new impulse [1].

Examiner insight (Cambridge 0610 June 2024 examiner report, Paper 42, Question 2(b)(ii)): A few candidates called the receptor molecules “cells” or invented names such as “receiver molecules”. Use the precise term: receptor proteins (or receptor molecules) on the next neurone.

Try the real question next: Cambridge IGCSE Biology 0610, June 2024, Paper 42, Question 2(b)(ii).

4. (Extended) The ciliary muscles contract [1], so the suspensory ligaments slacken [1]. The lens becomes more convex (fatter) [1], so light is refracted more and is focused on the retina [1].

Examiner insight (Cambridge 0610 June 2024 examiner report, Paper 42, Question 2(b)(iii)): A common error was to treat the ciliary muscles and suspensory ligaments as an antagonistic pair of muscles; ligaments are not muscles. Another was saying the lens “refracts more light” rather than that light is refracted more.

Try the real question next: Cambridge IGCSE Biology 0610, June 2024, Paper 42, Question 2(b)(iii).

5. (Extended) Any four of: both are found in the retina [1]; the fovea contains mainly cones and no rods [1]; there are no rods or cones at the blind spot [1]; rods are sensitive to dim light and give black-and-white vision [1]; cones work in bright light and give colour vision, with different cones absorbing different wavelengths of light [1]. Max [4].

Examiner insight (Cambridge 0610 June 2024 examiner report, Paper 42, Question 2(c)): Only a few candidates mentioned that there are no rods or cones at the blind spot. Some said cones “are red, green or blue” instead of absorbing different wavelengths, or said receptors “see” light rather than detect it.

Try the real question next: Cambridge IGCSE Biology 0610, June 2024, Paper 42, Question 2(c).

6. (a) His pupils become smaller (narrower / constrict) [1].

(b) Less light enters the eye, which protects the retina from damage by bright light [1].

(c) It is automatic: it happens without conscious thought [1].

Tip: Be clear about cause and effect: the muscles of the iris change the size of the pupil, which controls how much light reaches the retina. Say “the pupil gets smaller”, not “the eye gets smaller”.

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Where marks are usually lost

• Defining a sense organ without mentioning receptor cells.
• Describing ligaments as muscles, or saying the lens “refracts more light”.
• Forgetting the blind spot has no rods or cones.
• Saying cones “are red, green or blue” instead of absorbing different wavelengths.
• Vague synapse answers that miss diffusion across the gap or binding to receptor proteins.