External Web sites
- Brooklyn College at Brooklyn - Mutation Definition
- Fact Monster - Science - Mutation
- Kansas State University - Mutation, Mutagens, and DNA Repair
- National Center for Biotechnology Information - Types and Causes of Mutations
- North Dakota State University - Types of Mutations
- Understanding Evolution - Mutations
Britannica Web sites
Articles from Britannica encyclopedias for elementary and high school students.
- mutation - Children's Encyclopedia (Ages 8-11)
A mutation is a mistake or a change in a living thing’s DNA. DNA, or deoxyribonucleic acid, is a chain of chemical units found in each cell of a living thing. The chemical units are arranged in a particular sequence, or order. This sequence forms a kind of code, called a genetic code, that tells cells what to do. If the chain gets out of order, breaks, or changes in some other way, a mutation has occurred.