Which of the following describes a gene located on an autosome, rather than a sex chromosome?

• A. Autosomal
• B. X-linked
• C. Y-linked
• D. Dominant

Answer: (A)

A gene located on an autosome is described as autosomal. Autosomes are the chromosomes that are not involved in determining the sex of an organism; in humans, there are 22 pairs of autosomes and one pair of sex chromosomes (X and Y). Therefore, when referring to genes that are located on these non-sex chromosomes, the term "autosomal" is appropriate.

In contrast, X-linked genes are specifically located on the X chromosome, and Y-linked genes are on the Y chromosome. The term "dominant" refers to a type of inheritance pattern rather than a chromosomal location and can apply to genes on either autosomes or sex chromosomes. Thus, the designation of a gene as "autosomal" directly indicates that it is found on one of the non-sex chromosomes.