# Explain why simple reflex actions are important for survival, and describe the role of effectors in producing a response.

> AQA A-Level Biology (7402) — 3.6.1 Stimuli and Responses · Explain · 5 marks

> A cat steps on a sharp thorn and immediately withdraws its paw. This response happens without the cat deciding to move its paw.

## Mark scheme (5 marks)

1. Simple reflexes are automatic / do not require conscious thought
2. Reflexes are rapid / faster than voluntary responses
3. This protects the organism from damage / harm (survival advantage)
4. Effectors are muscles or glands that carry out the response
5. The effector receives a motor neurone signal and produces the response (e.g. muscle contracts to withdraw the paw)

## Key terms

- [simple reflex](https://www.gradenine.co.uk/glossary/simple-reflex)
- [effector](https://www.gradenine.co.uk/glossary/effector)
- [response](https://www.gradenine.co.uk/glossary/response)

## Related

- [Revision notes for AQA A-Level Biology (7402)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-simple-reflex-actions-are-fd517c1b) · Published by Druglandscape Ltd.