# A chromosome is described as a long, coiled molecule of DNA that carries genetic information in the form of genes. State what is meant by the term 'gene' and explain how the sequence of bases in a gene determines the specific protein produced in a cell.

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

## Mark scheme (4 marks)

1. A gene is a length of DNA that codes for the production of a specific protein.
2. The sequence of bases in the gene determines the sequence of amino acids in the protein.
3. Different sequences of amino acids produce proteins with different shapes.
4. Each protein has a specific shape that allows it to carry out a specific function.

## Key terms

- [gene](https://www.gradenine.co.uk/glossary/gene)
- [chromosome](https://www.gradenine.co.uk/glossary/chromosome)
- [sequence of bases](https://www.gradenine.co.uk/glossary/sequence-of-bases)
- [protein](https://www.gradenine.co.uk/glossary/protein)

## 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-chromosome-is-described-as-a-50a85721) · Published by Druglandscape Ltd.