# Explain why a second infection by the same pathogen is usually overcome much more quickly than the first infection.

> WJEC GCSE Biology (Wales) — 2.6.2 The immune system · Explain · 4 marks

> When a person catches a disease for the first time, it can take the immune system up to two weeks to overcome the infection. If the same pathogen enters the body again at a later date, the person rarely becomes ill at all.

## Mark scheme (4 marks)

1. Memory cells are produced after the first infection
2. Memory cells recognise the same antigen when the pathogen enters again
3. Antibodies are produced more rapidly / in greater quantities on second exposure
4. The pathogen is destroyed before it can multiply enough to cause symptoms / illness

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](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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