# A student states: 'Every cell in a human body contains the same genes, so every cell must make the same proteins.' Explain why this statement is incorrect.

> Cambridge International IGCSE Biology (0610) — 17.1 Chromosomes, genes and proteins · Explain · 4 marks

## Mark scheme (4 marks)

1. All cells contain the same genes / same DNA / same genetic information
2. Genes can be switched on or off in different cell types
3. Only the genes that are switched on / expressed are used to make a protein in that cell
4. Different cell types produce different proteins because they have different genes switched on / expressed, giving them different functions

## Key terms

- [gene](https://www.gradenine.co.uk/glossary/gene)

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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-states-every-cell-in-528baf5f) · Published by Druglandscape Ltd.