Practise 37 exam-style questions on Structure and function for AQA GCSE Biology. Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.
37 questions
1–5 marks each
Instant marking
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20 questions, marked as you go
Sample questions with model answers
Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.
Question 1
2 marks
Define a reflex action and give one reason why reflexes are important.
Model answer
reflex action = rapid, involuntary response to a stimulus without conscious thought; important for protection (e.g., withdrawal from hot object).
Explanation
Reflex actions are fast, automatic responses that bypass conscious processing to protect the body and maintain vital functions, such as preventing injury or stabilising blood pressure.
Mark scheme
1 mark
rapid, involuntary automatic response to a stimulus (does not involve conscious brain)
1 mark
protects from harm / maintains homeostasis (example: blink, withdraw from pain)
Question 2
3 marks
Explain why synapses can filter out low-frequency impulses but reliably pass high-frequency bursts.
Model answer
low-frequency release leads to insufficient neurotransmitter to reach threshold on postsynaptic cell; high-frequency increases amount of neurotransmitter accumulating and temporal summation produces an action potential.
Explanation
A single presynaptic impulse may produce a subthreshold postsynaptic potential. Repeated high-frequency firing leads to temporal summation of neurotransmitter action and excitatory postsynaptic potentials, enabling the postsynaptic neuron to reach threshold and fire.
Mark scheme
1 mark
single/low-frequency impulses release small amounts of neurotransmitter
1 mark
high-frequency impulses cause more neurotransmitter release and accumulation
1 mark
temporal summation of EPSPs reaches threshold and triggers postsynaptic action potential
Question 3
3 marks
Explain why increased myelination during development improves cognitive processing speed in children.
Model answer
myelination increases conduction velocity by saltatory conduction, reducing synaptic delays and enabling faster neural communication across networks important for cognitive tasks, leading to improved processing speed.
Explanation
As axons become myelinated, signals travel faster and brain networks can communicate more rapidly, supporting quicker information processing and cognitive development.
faster transmission reduces delay between regions/neurones
1 mark
enables quicker integration and processing in networks ? improved cognitive processing speed
Question 4
4 marks
Describe how the structure and arrangement of sensory receptors in the skin affect spatial resolution (two-point discrimination).
Model answer
receptors are denser in areas with high spatial resolution (fingertips) and receptor receptive fields are smaller allowing discrimination of two nearby points; less dense and larger fields in areas like the back give poor resolution.
Explanation
Spatial acuity depends on how many receptors are present and the size of receptive fields. Dense packing and little convergence support fine discrimination in regions such as fingertips.
Mark scheme
1 mark
high receptor density increases spatial resolution
1 mark
small receptive fields allow discrimination of two close points
1 mark
areas with low density and large receptive fields (e.g., back) have poor two-point discrimination
1 mark
convergence of multiple receptors onto single neurones reduces resolution
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