In an experiment, a substance stops an impulse travelling along a sensory neurone. No other part of the pathway is affected. The receptor is stimulated, but no impulse reaches the relay neurone.
Neurotransmitter is then applied directly to the appropriate receptors on the relay neurone.
Which result is expected?
an impulse can start in the relay neurone despite the block in the sensory neurone
an impulse stops in the motor neurone because neurotransmitter blocks every synapse
an impulse starts in the sensory neurone because neurotransmitter repairs its axon
an impulse cannot start in the relay neurone because the sensory neurone is blocked
43 exam-style questions on Edexcel GCSE Biology 2.3 The nervous system and brain, covering 2.3.1 Structures and functions of the brain, 2.3.2 Imaging brain function with scanning, 2.3.3 Limitations in treating nervous system damage, 2.3.4 Neurones and impulse transmission, and 2.3.5 Structure and function of a reflex arc. Each one has a worked solution and a mark scheme showing where the marks go.