Sex-linked gene

Definition
noun, plural: sex-linked genes
A gene located in the sex chromosome.
Supplement
In humans, the sex chromosomes are the X chromosome and Y chromosome. Hence, a sex-linked gene may occur in either of these sex chromosomes. Since the X chromosome is a rather large structure than the Y chromosome, the X chromosome carries more genes, which may not be found in Y chromosome. Thus, there are more sex-linked genes found in the X than in Y chromosome.
Examples of sex-linked genes are those genes that code for X-linked traits such as red-green colour blindness and haemophilia.
See also: sex-linked disorder