Biology 9700 · AS & A Level · Control and coordination in mammals
Control and coordination in mammals — practice question
A neuromuscular junction makes it possible for an action potential to pass from a motor neurone to a striated muscle fibre, which then contracts. Fig. 9.1 shows the graph of an action potential in a motor neurone.
(a)[4]
Using Fig. 9.1 and Fig. 9.2, compare the action potential in a motor neurone with the action potential in a striated muscle fibre.
(b(i))[3]
Using Fig. 9.3, explain what is occurring in the striated muscle fibre during the latent phase.
(b(ii))[1]
State 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 of motor neurone is less negative” …