# Explain how the immune system responds when a pathogen enters the body for the first time and produces antibodies to destroy it.

> Edexcel GCSE Biology (1BI0) — 5.2 Pathogens and immunity · Explain · 4 marks

## Mark scheme (4 marks)

1. The pathogen carries antigens on its surface
2. B-lymphocytes are activated / respond to the specific antigen
3. B-lymphocytes produce antibodies specific to that antigen
4. Antibodies bind to the antigens, triggering destruction / neutralisation of the pathogen, and the response is slower on first exposure (no memory cells yet)

## Related

- [Revision notes for Edexcel GCSE Biology (1BI0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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