Explain what is meant by a reflex action and why reflex actions are important for survival.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A person accidentally touches a sharp nail and immediately pulls their hand away before they feel pain.
Model answer (4 marks)
A reflex action is a rapid, automatic response to a stimulus that does not involve conscious thought.
It protects the body from damage or harm.
Because it is rapid, the response occurs before conscious awareness, so no time is wasted processing information in the brain.
It protects the body from damage or harm.
Because it is rapid, the response occurs before conscious awareness, so no time is wasted processing information in the brain.
Examiner tips
- Use the exact wording ‘rapid, automatic response’ and ‘does not involve conscious thought’.
- Explain the protective function and the speed advantage.
Common mistakes
- Confusing a reflex with a voluntary action or including unnecessary detail about the nervous system.
Mark scheme (4 marks)
- A reflex action is a rapid response to a stimulus
- A reflex action is automatic / does not involve conscious thought
- Reflex actions protect the body from damage / harm
- Because they are rapid, there is no time wasted processing information in the brain / response happens before conscious awareness
Key terms in this question
Related
- Revision notes: The human nervous system →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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