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

Control and coordination in mammals — practice question

Nerve impulses may travel along a myelinated motor neurone to a neuromuscular junction at high speeds, reaching up to $100\,\mathrm{m\,s^{-1}}$.
(a)[3]

Outline how the neurone achieves a transmission speed of $100\,\mathrm{m\,s^{-1}}$.

(b)[4]

When a nerve impulse arrives at the neuromuscular junction, acetylcholine is released and diffuses to the sarcolemma. Describe how the release of acetylcholine can result in the binding of calcium ions to troponin in the sarcomere.

(c)[3]

A low blood glucose concentration may influence muscle contraction. Suggest how a low blood glucose concentration would affect the functioning of the sarcomere.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Myelin sheath / Schwann cells serve as an insulator or stop ion movement

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