IUPAC definition : A heritable change in the nucleotide sequence of genomic DNA (or RNA in RNA viruses),
or in the number of genes or chromosomes in a cell, which may occur spontaneously
or be brought about by chemical mutagens or by radiation (induced mutation).;
A heritable change in the nucleotide sequence of genomic DNA (or RNA in RNA viruses),
or in the number of genes or chromosomes in a cell, which may occur spontaneously
or be brought about by chemical mutagens or by radiation (induced mutation).