Lesson 8.1.1

8.1.1 Sensory, relay and motor neurones and responses to stimuli Quiz: Pearson Edexcel Biology A (Salters-Nuffield), Unit 8

20 questions

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Lesson 8.1.1, Sensory, relay and motor neurones and responses to stimuli: 20 multiple choice questions for the Pearson Edexcel Biology A (Salters-Nuffield) (9BI0), Unit 8: Grey Matter, written with Revision Ninja.

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The 20 questions

  1. Which type of neurone carries impulses from receptors towards the central nervous system?

    • Relay neurone, which lies entirely within the central nervous system and connects one neurone to another
    • Sensory neurone, which carries impulses from receptors in the body towards the central nervous system
    • Glial neurone, a supporting cell type that insulates axons and helps to maintain the environment around neurones
    • Motor neurone, which carries impulses from the central nervous system out to effectors such as muscles and glands

  2. Which type of neurone carries impulses from the CNS to an effector such as a muscle or gland?

    • Motor neurone, which carries impulses away from the central nervous system to muscles and glands
    • Bipolar neurone in the retina only, which carries light signals from the rods and cones towards the brain
    • Sensory neurone, which carries signals from receptors in the skin and organs towards the central nervous system
    • Relay neurone only, which passes signals within the brain and spinal cord but not to any effector

  3. Where are relay neurones found?

    • Only at the neuromuscular junction, where they release acetylcholine onto the muscle fibre membrane
    • Only in skeletal muscle, where they control the contraction of individual fibres during movement
    • Entirely within the central nervous system, connecting sensory and motor neurones
    • Only in the peripheral nerves, which run from the spinal cord out to the muscles and the skin

  4. What is the role of Schwann cells in a myelinated neurone?

    • They produce neurotransmitter molecules that are released into the synaptic cleft to stimulate the next neurone
    • They wrap around the axon to form a myelin sheath that insulates it, in the peripheral nervous system
    • They make up the synaptic cleft and hold the presynaptic and postsynaptic membranes apart from one another
    • They detect stimuli at the receptor and convert the stimulus energy into an electrical signal

  5. Which structure of a motor neurone contains the cell nucleus and most of the organelles?

    • Myelin sheath, the fatty layer formed by Schwann cells that wraps around the axon at intervals
    • Axon terminal, the swollen end of the axon where neurotransmitter vesicles are stored and released
    • Node of Ranvier, the short gap between two adjacent myelin sheaths where the membrane is exposed
    • Cell body, the region that contains the nucleus and most of the organelles needed to maintain the neurone

  6. What is the function of the dendrites of a neurone?

    • To receive impulses from other neurones and carry them towards the cell body
    • To produce myelin, which is secreted by the dendrites to insulate the axon of the neurone
    • To release neurotransmitter into the synapse only, once the impulse has arrived at the end of the neurone
    • To carry impulses away from the cell body along the length of the neurone to the synaptic knob

  7. Which pathway correctly describes a simple reflex arc?

    • Effector, sensory neurone, relay neurone, motor neurone, receptor, with the impulse starting at the muscle
    • Receptor, sensory neurone, relay neurone, motor neurone, effector, in the order the impulse travels
    • Effector, motor neurone, relay neurone, sensory neurone, receptor, in the order the signal travels back to the body
    • Receptor, motor neurone, relay neurone, sensory neurone, effector, with the signal moving in the opposite direction

  8. A student touches a hot object and quickly withdraws her hand. Which statement best describes the response?

    • The response is slow and requires conscious thought, since the student must first recognise that the object is hot
    • The response is a rapid, involuntary reflex co-ordinated by the spinal cord, without waiting for the brain to decide
    • The response is controlled only by hormones released from the adrenal glands during the moment of contact
    • The response happens only after the brain has fully analysed the stimulus and decided on a suitable action

  9. Which statement describes the role of an effector in a response to a stimulus?

    • It transmits the impulse to the CNS along a sensory neurone, where the signal is processed
    • It stores information about the stimulus so that the body can respond faster the next time it occurs
    • It detects the stimulus and converts it into an electrical signal that can be sent to the central nervous system
    • It carries out the response, such as contraction of a muscle or secretion from a gland

  10. Which feature of myelinated neurones allows impulses to travel faster than in unmyelinated neurones of the same diameter?

    • Myelin stores extra ions for the impulse, which are released in a burst to drive the impulse forward
    • Impulses jump between nodes of Ranvier, a process called saltatory conduction, which speeds up transmission
    • Impulses travel continuously along the membrane, which gives a steady speed along the whole length of the axon
    • The axon is wider at the myelin sheath, which lowers the resistance and so increases the speed of the impulse

  11. A motor neurone has an axon of length 1.2 m and an impulse travels along it at 100 m per second. How long does the impulse take to travel the full length of the axon?

    • 1.2 s, found by taking the distance of 1.2 m as the time for the impulse to travel the axon
    • 0.12 s, found by multiplying the distance of 1.2 m by one tenth of the speed in metres per second
    • 0.012 s, found by dividing the distance of 1.2 m by the speed of 100 m per second
    • 120 s, found by multiplying the speed of 100 m per second by the distance of 1.2 m for the axon

  12. In an experiment, a student measures a reflex response time of 0.25 s, but estimates from the distance involved that the impulse conduction alone should take 0.02 s. What accounts for the difference?

    • Synaptic delays and processing time in the CNS, plus the time taken for the effector to produce its response
    • Impulses travel faster than light, so the conduction time is always shorter than the time measured in the experiment
    • Receptors take 0.23 s to detect any stimulus, and this time is always added before the impulse begins to travel
    • Motor neurones do not conduct impulses at all, so the measured time reflects only the muscle's own contraction

  13. A student records a stimulus-response time for a reflex and finds it shorter when the reflex arc has fewer synapses. Which statement is best supported by this result?

    • Synapses speed up impulses, since each synapse boosts the strength of the signal as it passes between neurones
    • Synapses stop impulses entirely, which means a shorter pathway allows the signal to bypass the blockage
    • Each synapse adds a delay, so fewer synapses give a faster response
    • Fewer synapses cause hormones to be released, which speeds up the response by a chemical route

  14. Which statement describes the difference between a sensory neurone and a motor neurone in terms of the position of their cell bodies?

    • Motor neurones have no cell body, since the axon connects directly to the effector without a central region
    • Both have cell bodies in the same position, which is inside the spinal cord in every case of the reflex arc
    • Sensory neurones have cell bodies in ganglia outside the CNS, whereas motor neurones have cell bodies inside the CNS
    • Sensory neurones have cell bodies in the CNS, whereas motor neurones have cell bodies in the peripheral nervous system

  15. Which term describes the gap between two neurones where neurotransmitter passes?

    • Synapse, the junction between two neurones where chemical transmission takes place
    • Node of Ranvier, a gap in the myelin sheath of a single axon where the membrane is exposed to the fluid
    • Myelin sheath, the fatty layer formed by Schwann cells that wraps around the axon at intervals
    • Axon hillock, the region at the cell body where the axon begins and where action potentials are initiated

  16. Which adaptation of a sensory neurone allows it to carry the impulse from a receptor?

    • It has a cell body inside the muscle, which allows the impulse to be generated at the effector
    • It has no axon at all, so the impulse passes directly from the receptor to the cell body
    • It has a very short axon with no myelin, which makes the impulse travel more slowly to the CNS
    • It has a long dendrite connecting the receptor to the CNS, with the cell body lying along the pathway

  17. A patient has damage to the myelin sheath of their motor neurones. What is the most likely consequence?

    • Faster conduction of impulses along the neurones, since the exposed membrane allows ions to move more quickly
    • Slower conduction of impulses, leading to slower responses, since saltatory conduction is lost
    • Complete loss of all sensory input, since the myelin is the only link between the receptors and the spinal cord
    • Increased production of hormones by the spinal cord, which compensates for the damage to the motor neurones

  18. Which statement best explains why a reflex response is described as involuntary?

    • It is caused by hormones acting slowly over several minutes, which triggers the response only after a delay
    • It is controlled by conscious thought in the cerebral cortex, which decides when the reflex should occur
    • It is a rapid, automatic pathway through the spinal cord that does not require conscious decision
    • It happens only during sleep, when the cerebral cortex is inactive and the reflex can take over control

  19. An axon is myelinated at intervals of 2 mm, leaving nodes of Ranvier between the sheaths. If an axon is 10 mm long, how many nodes of Ranvier are there between the sheaths, assuming one node between each pair of adjacent sheaths?

    • 4, which is one fewer than the number of sheaths, since there is one gap between each pair of adjacent sheaths
    • 5, which is the number of sheaths of 2 mm that fit along the 10 mm length of the axon
    • 10, which is the total length of the axon in millimetres, since there is one node per millimetre of axon
    • 6, which is the number of 2 mm sections plus one extra node at the start and the end of the axon

  20. Which evaluation is best for the claim that all neurones in the body have the same structure?

    • Incorrect, because only motor neurones contain a nucleus, while sensory and relay neurones have no genetic material
    • Incorrect, because neurones differ in structure, with dendrites, axons and cell bodies arranged to suit their function
    • Correct, because all neurones have identical axons and cell bodies, which is why they all carry impulses in the same way
    • Correct, because all neurones have no dendrites, which is why their impulses are carried only along the axon

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