# Describe the structure of a DNA molecule.

> WJEC GCSE Biology (Wales) — 2.3.1 DNA structure · Describe · 4 marks

## Mark scheme (4 marks)

1. DNA is made up of two strands / is double-stranded
2. The two strands are twisted / coiled to form a double helix
3. Each strand is made up of nucleotides / the molecule is made of nucleotides
4. Each nucleotide contains a base, and the bases pair up / complementary base pairing holds the two strands together (A with T; C with G)

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/describe-the-structure-of-a-dna-e2e5a239) · Published by Druglandscape Ltd.