# T-lymphocytes and B-lymphocytes both play important roles in the immune response. Explain how these two types of white blood cell work together when the body is infected by a pathogen for the first time, and describe what happens to some of the B-lymphocytes after the infection has been cleared.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 5.3 Immune response · Explain · 5 marks

## Mark scheme (5 marks)

1. The pathogen carries antigens on its surface / antigens are unique chemicals on the surface of the pathogen
2. T-lymphocytes detect / respond to the foreign antigen and activate / stimulate B-lymphocytes
3. B-lymphocytes produce antibodies specific to / complementary to that antigen
4. Antibodies bind to / attach to the antigens on the pathogen, leading to destruction / neutralisation of the pathogen
5. Some B-lymphocytes remain as memory cells / are retained after the infection, so the body can respond faster / produce antibodies more quickly if the same pathogen is encountered again

## Key terms

- [B-lymphocyte](https://www.gradenine.co.uk/glossary/b-lymphocyte)
- [T-lymphocyte](https://www.gradenine.co.uk/glossary/t-lymphocyte)

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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/t-lymphocytes-and-b-lymphocytes-both-play-important-81230889) · Published by Druglandscape Ltd.