a permanent structural alteration in DNA. In most cases, DNA changes either have no effect or cause harm, but occasionally a mutation can improve an organism's chance of surviving and passing the beneficial change on to its descendants
A permanent change in a cell's genetic material (DNA). Can be the result of natural errors that occur during thecell division process, or can be caused by external factors such as radiation, chemicals, or viruses.
(genetics) any event that changes genetic structure; any alteration in the inherited nucleic acid sequence of the genotype of an organism