# A student cuts their hand and bacteria enter the body through the wound. Explain how T-lymphocytes and B-lymphocytes work together to destroy the bacteria.

> Pearson Edexcel A-Level Biology A (9BI0) — 5.3 Immune response · Explain · 5 marks

> When the skin is broken, pathogens can enter the body and trigger an immune response involving several types of white blood cell.

## Mark scheme (5 marks)

1. Bacteria have antigens on their surface / antigens are unique chemicals on the surface of the bacteria
2. T-lymphocytes detect / recognise the foreign antigens and activate B-lymphocytes
3. B-lymphocytes produce antibodies specific to the antigen on the bacteria
4. Antibodies bind to the antigens on the bacteria, marking / clumping them for destruction / neutralising them
5. Memory cells are produced so that if the same bacteria enter again, the response is faster / greater quantity of antibodies is produced more quickly

## 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 Pearson Edexcel A-Level Biology A (9BI0)](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/a-student-cuts-their-hand-and-b47b96cd) · Published by Druglandscape Ltd.