Biology 9700 · AS & A Level · Control and coordination in mammals
Control and coordination in mammals — practice question
A neuromuscular junction is the site at which an action potential is passed from a motor neurone to a striated muscle fibre, leading to contraction of the fibre. Fig. 9.1 shows the graph of an action potential in a motor neurone. Fig. 9.2 shows the graph of an action potential in a striated muscle fibre.
(a(i))[4]
With reference to Fig. 9.1 and Fig. 9.2, Describe how the action potential in a motor neurone differs from the action potential in a striated muscle fibre.
(b(i))[3]
With reference to Fig. 9.3, Explain what is occurring in the striated muscle fibre during the latent phase.
(b(ii))[1]
Suggest why the relaxation phase shows a gradual fall in muscle tension.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “resting potential higher in motor neurone” …