# Explain how the structure of a DNA nucleotide relates to its function in storing genetic information.

> AQA A-Level Biology (7402) — 3.1.5 Nucleic Acids · Explain · 5 marks

> DNA is a polymer made from nucleotide monomers. The sequence of bases in DNA acts as a code for the sequence of amino acids in a protein.

## Mark scheme (5 marks)

1. A DNA nucleotide contains a deoxyribose sugar, a phosphate group, and a (nitrogenous) base
2. There are four different bases (adenine, thymine, cytosine, guanine) in DNA
3. The sequence / order of bases acts as a code / carries the genetic information / instructions for making proteins
4. Bases pair specifically / complementary base pairing (A with T, C with G) holds the two strands together
5. The double-stranded / double helix structure with complementary base pairing allows accurate copying / replication of genetic information

## Key terms

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

## Related

- [Revision notes for AQA A-Level Biology (7402)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-structure-of-a-564d8b91) · Published by Druglandscape Ltd.