# Explain how memory cells protect the body more effectively when the same pathogen enters the body for a second time.

> WJEC A-Level Biology (Wales) — 3.4 Population size and ecosystems · Explain · 5 marks

> When a person recovers from an infection, a small number of white blood cells remain in the body as memory cells. These memory cells can provide long-lasting protection against the same pathogen.

## Mark scheme (5 marks)

1. Memory cells remain in the body after the first infection / are long-lasting
2. Memory cells recognise the same antigen / pathogen when it enters the body again
3. Memory cells divide rapidly / more quickly than during the first infection
4. Large quantities of the specific antibody are produced more quickly
5. The pathogen is destroyed before symptoms develop / the person does not become ill

## Key terms

- [memory cell](https://www.gradenine.co.uk/glossary/memory-cell)
- [pathogen](https://www.gradenine.co.uk/glossary/pathogen)

## Related

- [Revision notes for WJEC A-Level 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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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-memory-cells-protect-the-78a7c361) · Published by Druglandscape Ltd.