Coordination and response — Paper 2 · IGCSE Biology (9-1) 0970

23 Four processes occur when impulses cross a synapse. P neurotransmitter diffuses across the gap Q neurotransmitter binds with receptors R impulse stimulates vesicles S release of neurotransmitter What is the correct sequence for these processes? A P → R → Q → S B R → P → Q → S C R → S → P → Q D S → Q → R → P

1 marks

Answer: C

This question in 0970/21 May/June 2018

23 What does the central nervous system consist of? A brain, spinal cord and peripheral nerves B brain and spinal cord only C brain only D spinal cord and peripheral nerves only

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2018

24 A student used two seedlings X and Y to investigate phototropism. The diagram shows their investigation. light light piece of glass piece of glass X X at the start of after some time the experiment no curvature towards light light light piece of glass piece of glass Y Y at the start of after some time the experiment gives curvature towards light Which statement explains the difference in results between X and Y? A The piece of glass destroyed the auxin on the shaded side of the seedling. B The piece of glass destroyed the auxin on the side of the seedling facing the light. C The piece of glass in X stopped the auxin travelling down the shaded side of the seedling. D The piece of glass in X stopped the auxin travelling down the side of the seedling facing the light.

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2018

24 The components of a reflex arc are shown in the flow diagram. receptor → sensory relay motor → synapse → → synapse → neurone → effector neurone neurone Which component is responsible for ensuring that the nerve impulses travel in one direction only? A motor neurone B receptor C sensory neurone D synapse

1 marks

Answer: D

This question in 0970/21 May/June 2019

24 Which statement about involuntary responses is correct? A They always result in the same response to the same stimulus. B They are learned responses. C They are slower than voluntary responses. D They never use voluntary muscles.

1 marks

Answer: A

This question in 0970/22 May/June 2019

28 The diagram shows a synapse. Heroin affects the neurone. Which labelled part does the heroin directly affect? direction of A movement of impulse B C D

1 marks

Answer: C

This question in 0970/22 May/June 2019

22 Which process transmits an impulse across a synapse? A active transport B diffusion C gravity D osmosis

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2019

23 The diagram shows the muscles that control the size of the pupil in an eye. iris circular muscles radial muscles pupil How do the muscles make the pupil smaller? circular muscles radial muscles A contract contract B contract relax C relax contract D relax relax

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2019

1 The diagram shows what happened in an experiment with plant seedlings. start next day light light Which characteristic of living things made the seedlings grow towards the light? A excretion B nutrition C respiration D sensitivity

1 marks

Answer: D

This question in 0970/21 May/June 2020

24 The diagram shows a synapse. W nerve ending of neurone 1 Y X Z membrane of neurone 2 What are the labelled parts? W X Y Z A synaptic cleft neurotransmitter vesicle receptor B synaptic cleft receptor vesicle neurotransmitter C vesicle neurotransmitter synaptic cleft receptor D vesicle receptor synaptic cleft neurotransmitter

1 marks

Answer: C

This question in 0970/21 May/June 2020

24 Which responses occur in the iris of the eye when a person walks from a brightly lit area to a dimly lit area? circular muscle radial muscle A contract contract B contract relax C relax contract D relax relax

1 marks

Answer: C

This question in 0970/22 May/June 2020

23 Which structure contains relay neurones? A gland B muscle C spinal cord D synapse

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2020

24 A man injures his arm in an accident. Afterwards, he can move his hand but cannot feel objects touching his hand. What could cause this? A Both sensory and motor neurones are cut. B Effectors are damaged. C Motor neurones are cut. D Sensory neurones are cut.

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2020

26 The diagram shows the appearance of an eye when in bright light. bright light Which row gives the correct states of the iris muscles in bright light? radial muscles circular muscles A contracted contracted B contracted relaxed C relaxed contracted D relaxed relaxed

1 marks

Answer: C

This question in 0970/21 May/June 2021

25 The structures listed are part of the nervous system. 1 brain 2 effector 3 receptor 4 relay neurone In a reflex arc, which structures are connected to a motor neurone by synapses? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2021

27 Which row shows the pupil reflex in bright light? muscles in iris size of pupil circular radial A contracts relaxes larger B contracts relaxes smaller C relaxes contracts larger D relaxes contracts smaller

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2021

25 Which hormone causes an increase in breathing rate, an increase in heart rate and the widening of pupils? A insulin B adrenaline C oestrogen D testosterone

1 marks

Answer: B

This question in 0970/22 Oct/Nov 2022

24 The events listed involve neurotransmitter molecules at a synapse. 1 They bind with receptor proteins. 2 They diffuse across the synaptic gap. 3 They enter the synaptic gap. 4 They are released from vesicles. What is the sequence of events that occur when an impulse arrives at the synapse? A 3 → 2 → 1 → 4 B 4 → 3 → 1 → 2 C 3 → 4 → 1 → 2 D 4 → 3 → 2 → 1

1 marks

Answer: D

This question in 0970/21 May/June 2023

24 Which statement describes what happens during the transmission of an electrical impulse along a reflex arc? A The relay neurone has receptor proteins which bind with neurotransmitter molecules. B The relay neurone has vesicles which bind with neurotransmitter molecules. C The sensory neurone causes receptor proteins to release neurotransmitter molecules. D The sensory neurone impulses cause vesicles to release receptor protein molecules.

1 marks

Answer: A

This question in 0970/22 May/June 2023

25 During the pupil reflex in bright light, what describes the actions of the muscles in the iris? A The circular muscles of the iris contract and the radial muscles relax. B The circular muscles of the iris contract and the radial muscles contract. C The circular muscles of the iris relax and the radial muscles contract. D The circular muscles of the iris relax and the radial muscles relax.

1 marks

Answer: A

This question in 0970/22 May/June 2023

26 The diagram shows a reflex arc in a human nervous system. The person’s finger has just made contact with a sharp object. Which part is the motor neurone? A B C D

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2023

26 The diagram shows a synapse in a reflex arc. P Q What are the identities of the two neurones and in which direction does the neurotransmitter pass? direction of passage neurone P neurone Q of the neurotransmitter A motor relay P  Q B motor sensory P  Q C relay motor Q  P D relay sensory Q  P

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2024

27 Which responses occur in the iris of the eye when a person walks from a brightly lit area to a dimly lit area? circular muscles radial muscles A contract contract B contract relax C relax contract D relax relax

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2024

21 The diagram shows a synapse. P neurone 1 R Q S neurone 2 What are the labelled parts? P Q R S A synaptic gap neurotransmitter vesicle receptor B synaptic gap receptor vesicle neurotransmitter C vesicle neurotransmitter synaptic gap receptor D vesicle receptor synaptic gap neurotransmitter

1 marks

Answer: C

This question in 0970/21 May/June 2025

24 The diagram shows a vertical section through part of a human eye. A fly is coming nearer to the eye. The eye begins to focus the image of the fly on the retina. Q fly R S How do the labelled parts of the diagram change? Q R S A contracts becomes thinner becomes tighter B relaxes becomes fatter becomes slacker C contracts becomes fatter becomes slacker D relaxes becomes thinner becomes tighter

1 marks

Answer: C

This question in 0970/22 May/June 2025

18 The diagram shows the parts of the nervous system involved in a reflex arc. Which letter identifies a synapse? section of the spinal cord A B D C

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2025