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Exam questions · Biology · Homeostasis and the Nervous System

Neurones and the Nervous System

  • 7 exam questions
  • 20 marks
  • 8 quick checks
  1. 1 State [2 marks]

    State the two parts of the central nervous system.

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    Model answer

    The brain and the spinal cord.

    Mark scheme

    • Brain — 1 mark
    • Spinal cord — 1 mark
  2. 2 Name [3 marks]

    Figure 1 shows a motor neurone. Name the parts shown at A, B and C.

    A motor neurone with three parts marked A, B and C.
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    Model answer

    A is the cell body. B is the axon. C is the myelin sheath.

    Mark scheme

    • A: cell body — 1 mark
    • B: axon — 1 mark
    • C: myelin sheath — 1 mark
  3. 3 State [3 marks]

    Figure 2 shows the path from a stimulus to a response. Name the parts shown at A, B and C.

    A flow chart with three boxes marked A, B and C.
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    Model answer

    A is a receptor. B is the central nervous system. C is an effector.

    Mark scheme

    • A: receptor — 1 mark
    • B: central nervous system — 1 mark
    • C: effector — 1 mark
  4. 4 Describe [3 marks]

    Describe the functions of sensory neurones, relay neurones and motor neurones.

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    Model answer

    Sensory neurones carry impulses from receptors to the central nervous system. Relay neurones carry impulses inside the central nervous system. Motor neurones carry impulses from the central nervous system to effectors.

    Mark scheme

    • Sensory: receptor to the central nervous system — 1 mark
    • Relay: within the central nervous system — 1 mark
    • Motor: central nervous system to effectors — 1 mark
  5. 5 Explain [3 marks]

    Explain how a nerve impulse crosses a synapse.

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    Model answer

    The impulse arrives at the nerve ending, which releases neurotransmitter. The neurotransmitter diffuses across the gap. It binds to receptors on the next neurone, which starts a new impulse.

    Mark scheme

    • Neurotransmitter released at the nerve ending — 1 mark
    • Diffuses across the gap — 1 mark
    • Binds to receptors on the next neurone to start an impulse — 1 mark
  6. 6 Explain [2 marks]

    Explain why a myelin sheath is an advantage to a long neurone.

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    Model answer

    The myelin sheath insulates the axon. This makes the impulse travel much faster, so the response is quicker.

    Mark scheme

    • Insulates the axon — 1 mark
    • Impulse travels faster — 1 mark
  7. 7 Explain [4 marks]

    Explain how the nervous system produces a coordinated response.

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    Model answer

    Receptors of different types detect stimuli and send impulses. The central nervous system receives the impulses through many connections. It sends impulses along nerves, which reach all parts of the body, to the effectors. The effectors, muscles or glands, then carry out the response.

    Mark scheme

    • Different receptors detect stimuli — 1 mark
    • Many links in the central nervous system — 1 mark
    • Nerves reach all parts of the body — 1 mark
    • Effectors carry out the response — 1 mark

Quick check

  1. 1

    What is the job of a sensory neurone?

    1. ATo carry impulses to a muscle
    2. BTo carry impulses from a receptor to the central nervous system
    3. CTo store memories
    4. DTo release hormones
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    B: To carry impulses from a receptor to the central nervous system

    A sensory neurone carries impulses from a receptor to the central nervous system.

  2. 2

    Which two structures make up the central nervous system?

    1. AThe heart and the lungs
    2. BThe eye and the ear
    3. CThe nerves and the muscles
    4. DThe brain and the spinal cord
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    D: The brain and the spinal cord

    The central nervous system is the brain and the spinal cord.

  3. 3

    What is an effector?

    1. AA muscle or a gland
    2. BA cell that detects light
    3. CA type of neurone
    4. DA part of the brain
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    A: A muscle or a gland

    Effectors are muscles and glands that carry out a response.

  4. 4

    What is the function of the myelin sheath?

    1. ATo store nutrients
    2. BTo make neurotransmitters
    3. CTo speed up the impulse
    4. DTo detect stimuli
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    C: To speed up the impulse

    The myelin sheath insulates the axon and speeds up the impulse.

  5. 5

    What is a synapse?

    1. AA type of neurone
    2. BA gap between two neurones
    3. CA muscle
    4. DThe cell body
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    B: A gap between two neurones

    A synapse is the small gap between two neurones.

  6. 6

    What crosses a synapse?

    1. AMyelin
    2. BBlood
    3. CHormones
    4. DNeurotransmitters
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    D: Neurotransmitters

    Neurotransmitter chemicals diffuse across the synapse.

  7. 7

    Which cells detect a stimulus?

    1. AReceptors
    2. BEffectors
    3. CRelay neurones
    4. DMotor neurones
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    A: Receptors

    Receptors detect stimuli and start impulses.

  8. 8

    Which of these carries impulses from the central nervous system to an effector?

    1. AA sensory neurone
    2. BA relay neurone
    3. CA motor neurone
    4. DA receptor
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    C: A motor neurone

    Motor neurones carry impulses to effectors.