n. any chromosome that is not a sex chromosome. A human normally has a total of 44 autosomes (arranged in 22 homologous pairs) in the nucleus of each body cell, although irregular numbers may occur through the loss or addition of one or more autosomes. If a homologous pair of autosomes has an extra chromosome, the condition is called trisomy. If one member of a homologous pair is absent, the condition is called monosomy.