A permanent change in the genetic sequence of an organism or virus.
Mutations can involve a change in one or more nucleotides, larger sections of DNA, or, in some contexts, changes affecting chromosomes. They can arise from errors during genetic-material replication, exposure to certain environmental factors, or other biological processes.
Mutations can have different effects. Some have little or no detectable effect, some alter biological functions, and others can contribute to disease. In viruses and microorganisms, mutations can sometimes contribute to changes in characteristics such as susceptibility to medicines.
QUICK FACT
A mutation is not necessarily harmful. Many mutations have no noticeable effect, while some can be beneficial or harmful depending on the circumstances.
COMMONLY CONFUSED WITH
Genetic variation: A mutation is a change in genetic sequence; genetic variation refers more broadly to differences in genetic characteristics between individuals or populations, which can arise from mutations and other processes.
SEE ALSO