What happens when an electrical impulse reaches the end of a neurone at a synapse?
a chemical is released and travels along the axon
a chemical is released and diffuses across the gap
an electrical impulse passes directly across the gap
an electrical impulse passes through the myelin sheath
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.