Question 1

Animals receive different stimuli from their environment. Their synapses can manage multiple stimuli, often resulting in one response (such as a muscle twitching).

What is this action of the synapse an example of?

  A  

spatial summation

  B  

all-or-nothing response

  C  

temporal summation

  D  

cell signalling

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Question 2

The diagram below refers to a synapse.

Which statement describes events occurring at a synapse?

  A  

acetylcholine is broken down by enzymes so that it can bind to structure K

  B  

an action potential causes structure J to close


  C  

structure J is a voltage gated Ca2+ channel

  D  

structure L is released by exocytosis

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Question 3

The diagram below refers to a synapse.

GABA is a neurotransmitter. GABA reduces the number of action potentials in the postsynaptic neurone by opening chloride ion channels in the postsynaptic membrane. 

Which statement describes the action of GABA?

  A  

GABA binds to structure K in competition with acetylcholine

  B  

GABA causes hyperpolarisation of the postsynaptic membrane

  C  

GABA causes depolarisation of the postsynaptic membrane

  D  

GABA inhibits release of neurotransmitter from structure L


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Question 4

Excitatory and inhibitory postsynaptic potentials have similarities and differences.

What is a feature of an excitatory, but not inhibitory, postsynaptic potential?

  A  

all-or-nothing response

  B  

depolarising

  C  

graded in response

  D  

hyperpolarising

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Question 5

Neurotransmitters such as GABA are found at synapses within the human brain and are known as inhibitory neurotransmitters.

GABA binds to receptors in the postsynaptic membrane and causes potassium ion channels to open.

Why does this prevent an action potential in the postsynaptic neurone?

  A  

because potassium ions diffuse out of the postsynaptic neurone causing depolarisation

  B  

because potassium ions diffuse out of the postsynaptic neurone causing hyperpolarisation

  C  

because potassium ions diffuse into the postsynaptic neurone causing depolarisation

  D  

because potassium ions diffuse into the postsynaptic neurone causing hyperpolarisation

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Question 6

What is temporal summation?

  A  

when neurotransmitters are released from multiple locations simultaneously

  B  

when a single presynaptic neuron releases neurotransmitter several times over a short period

  C  

when a neurotransmitter is released continuously without degradation

  D  

when neurotransmitters are released at a slower, more consistent rate

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Question 7

What occurs as a result of hyperpolarisation at an inhibitory synapse?

  A  

it makes it easier for the postsynaptic neuron to reach the threshold of excitation

  B  

it makes it more likely for the postsynaptic neuron to release neurotransmitters

  C  

it makes it less likely that a new action potential will be generated in the postsynaptic neuron

  D  

it makes it necessary for neurotransmitters to bind to their receptors

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Question 8

What happens when neurotransmitter molecules bind to receptor sites on the postsynaptic neuron?

  A  

neurotransmitter molecules are immediately broken down

  B  

an inhibitory postsynaptic potential is always generated

  C  

a new action potential may be initiated in the postsynaptic neuron

  D  

the presynaptic neuron is stimulated

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Question 9

What is the primary purpose of synaptic vesicles?

  A  

to store calcium ions needed for neurotransmission

  B  

to absorb excess neurotransmitter from the synaptic cleft

  C  

to provide energy for the synaptic transmission

  D  

to contain and release neurotransmitters into the synaptic cleft

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Question 10

During synaptic transmission, the opening of which ion channels directly triggers the release of neurotransmitter?

  A  

potassium

  B  

calcium

  C  

sodium

  D  

chloride

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Question 11

What effect does the enzyme acetylcholinesterase have in the synapse?

  A  

it generates action potentials in the presynaptic neuron

  B  

it facilitates the release of more acetylcholine

  C  

it stimulates the growth of synaptic vesicles

  D  

it breaks down acetylcholine in the synaptic cleft

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Question 12

What is the consequence of the influx of sodium ions into the postsynaptic neuron?

  A  

it leads to the neuron becoming negatively charged

  B  

it decreases the likelihood of an action potential

  C  

it inhibits neurotransmitter release from the presynaptic neuron

  D  

it can generate a new action potential

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