Mutations are genetic alterations in the nucleotide sequence that form the genome of a given organism. In general, mutations have negative effects (i.e., mutations are generally deleterious), but sometimes these genetic changes may be adaptive (and therefore beneficial). Somatic mutations are genetic alterations acquired by somatic cells (they can not be inherited by the offspring), while germline mutations occur in gametes (sperm and egg) and they can be inherited by the offspring, thereby affecting the progeny of the organism.
The genes of an organism can be
either a homozygous or a heterozygous one. When someone is a homozygous
dominant, it means that it has two copies of the same dominant allele. Homozygous
means that the organism has exact copies of the same gene allele.
