Autosomes refer to those pairs of Chromosomes found in the nucleus of the cell that has the Genes for somatic traits and is not useful in determining the sex of an individual. In the human cell, there are 23 pairs of autosomes. They code proteins for the normal metabolism of the human body that is not directly associated with the production of sexual characteristics and related molecules (sex hormones, etc.) in the life cycle of the species. The number of autosomes varies from species to species. It is however fixed for a particular species and does not alter (except during genetic disorders such as Down syndrome, Klinefelter syndrome, etc.)