1 Colored Egg Layer Chickens. The Araucana is a pure breed of chicken originating in Chile. 2  Ameraucana chickens were developed in the 1970âs in the United States from Araucanas. They were developed as a practical barnyard fowl that laid pastel shelled eggs, but without some of the limiting genetic factors related to rumplessness and tufts.
sex chromosome. a chromosome, differing in shape or function from other chromosomes, that determines the sex of an individual.
A gene located on any chromosome other than the sex chromosomes (X or Y). a gene found on an AUTOSOME. A gene found on one of the 22 autosomal chromosome pairs; i.e., not on a sex (X or Y) chromosome. Mentioned in: Glycogen Storage Diseases. a gene located on a chromosome other than the sex chromosomes.