# Describe how a nerve impulse is transmitted from one neurone to the next across a synapse.

> WJEC A-Level Biology (Wales) — 4.2 Inheritance · Describe · 5 marks

## Mark scheme (5 marks)

1. When an impulse arrives at the presynaptic neurone, a neurotransmitter is released
2. The neurotransmitter is released into the synaptic cleft
3. The neurotransmitter diffuses across the synapse
4. The neurotransmitter binds to receptors on the postsynaptic neurone
5. This triggers a nerve impulse in the postsynaptic neurone, propagating the impulse

## Key terms

- [synapse](https://www.gradenine.co.uk/glossary/synapse)

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-a-nerve-impulse-is-fa428199) · Published by Druglandscape Ltd.