Autosomes are: any chromosomes that isn't a sex chromosome. Humans consist of 22 pairs of autosomes (which is also sometimes called atDNA or auDNA). Autosomes are used to transfer genetic information from the parents to the offspring.
By contracting, muscles pull on bones and allow the body to move. Muscles can only contract. They cannot actively extend, though they can move or relax back into the non-contracted neutral position. Therefore, to move bones in opposite directions, pairs of muscles must work in opposition
