# A scientist extracts DNA from a sample of wheat cells. Explain how the structure of DNA allows it to carry the genetic information needed to produce different proteins.

> AQA A-Level Biology (7402) — 3.4.1 DNA, Genes and Chromosomes · Explain · 5 marks

## Mark scheme (5 marks)

1. DNA is made up of (repeating) nucleotides / DNA is a polymer of nucleotides
2. Each nucleotide contains a base, and there are four different bases (A, T, C, G)
3. The sequence / order of bases in a gene codes for a specific sequence of amino acids
4. Different genes have different base sequences, so different amino acid sequences are produced
5. The sequence of amino acids determines the shape / structure of the protein, which determines its function / different proteins are produced

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](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-scientist-extracts-dna-from-a-1e0fb114) · Published by Druglandscape Ltd.