# Explain how the structure of a DNA nucleotide allows DNA to store genetic information and to be replicated accurately.

> Edexcel GCSE Biology (1BI0) — 3.3 DNA structure · Explain · 4 marks

## Mark scheme (4 marks)

1. A nucleotide contains one of four chemical bases (A, T, C or G)
2. The sequence / order of bases along the DNA strand codes for / stores genetic information
3. Complementary base pairing means A pairs with T and C pairs with G
4. Complementary base pairing ensures an accurate copy of the base sequence is made during replication / each strand acts as a template

## Key terms

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

## Related

- [Revision notes for Edexcel GCSE Biology (1BI0)](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/explain-how-the-structure-of-a-32819f0c) · Published by Druglandscape Ltd.