https://doi.org/10.1351/goldbook.M04074
A heritable change in the @[email protected] @[email protected] of genomic @[email protected] (or @[email protected] in @[email protected] viruses), or in the number of @[email protected] or @[email protected] in a cell, which may occur spontaneously or be brought about by chemical mutagens or by radiation (induced mutation).