A disease destroys the myelin sheath around the axon of a motor neurone in a sheep. The axon, its synapses and the lower-leg muscle supplied by the neurone are not damaged.
What change in impulse transmission is expected?
The impulse becomes a chemical inside the axon and reaches the leg muscle later.
The impulse jumps across synapses in the axon and reaches the leg muscle sooner.
The impulse travels along each part of the axon membrane and reaches the leg muscle later.
The impulse travels along each part of the axon membrane and reaches the leg muscle sooner.
135 exam-style questions on OCR GCSE Biology 3.1 Coordination and control – the nervous system, covering 3.1.1 Structure of the nervous system, 3.1.2 Coordinated response, 3.1.3 The reflex arc, 3.1.4 Structure of the eye, 3.1.5 Defects of the eye, 3.1.6 Structure and function of the brain, 3.1.7 Difficulties of investigating brain function, and 3.1.8 Limitations in treating nervous system damage. Each one has a worked solution and a mark scheme showing where the marks go.