1. An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell typically have the same morphology (homomorphic), unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes is collectively known as atDNA or auDNA. == Nomenclature == The number of autosomal chromosomes an organism has can vary across species and cell types. They are typically identified by sequential numbers beginning with 1 (as opposed to the sex chromosomes which are indicated by letters). In diploid organisms, a somatic cell will contain two copies of each autosomal chromosome, one from each parent while germline cells (eggs or sperm) will typically contain a single copy of each autosome. The homologous chromosome pairs are identified with the same number (e.g. a somatic cell will have two copies of chromosome 1, two copies of chromosome 2...). === Humans === The human genome contains 44 autosomal chromosomes, or as a diploid... from wikipedia.org