Biology 9700 · AS & A Level · Control and coordination in mammals

Control and coordination in mammals — practice question

Fig. 8.1 shows a diagram of a sensory neurone.
(a(i))[1]

Name the cell type shown as cell A.

(a(ii))[1]

Name a cell type that makes a synapse with structure B.

(a(iii))[1]

Name the cells responsible for forming the myelin sheath.

(b)[4]

State and explain the differences in impulse transmission between myelinated and unmyelinated neurones.

(c(i))[2]

With reference to Fig. 8.2, describe how ion channel A differs from ion channel B.

(c(ii))[4]

Morphine binds to the opioid receptor in the presynaptic membrane, which prevents ion channel A from opening. Suggest and describe the effects of morphine binding to this opioid receptor on the functioning of the cholinergic synapse.

(c(iii))[2]

Morphine also binds to the opioid receptor in the postsynaptic membrane, causing ion channel C to open and allowing potassium ions to diffuse out of the cell. Suggest how this would affect the synapse.

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