autosome

Sort a cell's chromosomes into two groups: the small handful that help set whether the organism develops as male or female, and everything else. That “everything else” group is the autosomes — the chromosomes that carry the bulk of an organism's genes but are not the sex chromosomes.

In humans, 22 of the 23 chromosome pairs are autosomes, numbered 1 through 22 roughly from largest to smallest. The remaining pair is the sex chromosomes (X and Y). Autosomes come in matching pairs in both sexes, so a typical person inherits two copies of each autosomal gene — one from each parent.

Because autosomes are present in two copies regardless of sex, traits and disorders linked to them are inherited in patterns that do not depend on whether one is male or female. Geneticists describe these as autosomal dominant or autosomal recessive, distinguishing them from sex-linked patterns that ride along on the X or Y chromosome.