a sex chromosome found as one copy in male somatic cells.

The partner of the X-chromosome in the male of many animal species.

One of the two types of sex chromosome, X and Y. In humans, females have two X-chromosomes, while males have one X and one Y. The Y chromosome contains relatively few genes.

The sex chromosome associated with male characteristics in mammals, not occurring in females and occurring with one X-chromosome in the male sex-chromosome pair.

One of the two sex chromosomes, X and Y. The Y-chromosome passes down from father to son. Females do not receive it. The fact that the Y-chromosome goes down the paternal line makes it valuable for genealogy studies, since it typically follows a surname line.

See sex chromosome.

See X-chromosome.