# A student investigating immunity injects a mouse with a specific antigen. The mouse produces lymphocyte cells that make antibodies complementary to that antigen. The student then fuses the lymphocyte cells with tumour cells to produce hybridoma cells. Explain why the student fuses the lymphocyte cells with tumour cells, and describe what happens next to produce large numbers of monoclonal antibodies.

> WJEC A-Level Biology (Wales) — 3.2 Respiration · Explain · 5 marks

> Monoclonal antibodies are used in diagnostic tests for diseases such as HIV and Chlamydia. They are produced in a laboratory using hybridoma cells.

## Mark scheme (5 marks)

1. Lymphocyte cells alone cannot divide continuously / will die out
2. Tumour cells divide continuously / indefinitely
3. Hybridoma cells both divide continuously AND produce the specific antibody
4. Hybridoma cells producing the correct antibody are selected
5. Selected hybridoma cells are cultured to produce large numbers of identical / monoclonal antibodies

## Key terms

- [monoclonal antibodies](https://www.gradenine.co.uk/glossary/monoclonal-antibodies)
- [hybridoma cells](https://www.gradenine.co.uk/glossary/hybridoma-cells)
- [lymphocyte](https://www.gradenine.co.uk/glossary/lymphocyte)
- [antigen](https://www.gradenine.co.uk/glossary/antigen)

## 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/a-student-investigating-immunity-injects-a-e0b94003) · Published by Druglandscape Ltd.