Mutation
A random change in the DNA of a gene. Most are harmless, some are harmful and a few are useful.
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Analogy
A typo in a recipe. Mostly it makes no difference, sometimes it ruins the dish, rarely it improves it.
In practice
A mutation made some bacteria resistant to an antibiotic.
Practice
Flashcards
- What is a mutation?A random change in the DNA sequence of a gene.
Questions people ask
Are all mutations bad?
No. Most mutations do nothing because they change a part of the DNA that is not important or give the same protein. Some are harmful and can cause disease. A few help the organism, for example by making a bacterium resistant to an antibiotic, and natural selection can then favour them.
What causes mutations?
Mutations happen by chance when DNA is copied, but the rate increases with ionising radiation such as X-rays, ultraviolet light and some chemicals. These are called mutagens. Mutations in body cells can lead to cancer, but only mutations in sex cells can be passed to children.