sex chromosomesex chromosome
a sex-determining chromosome in the germ cells of most animals and a few plants: in most animals, including human beings, all the eggs carry an X chromosome and the spermatozoa either an X or a Y chromosome, and an egg receiving an X chromosome at fertilization will develop into a female (XX) while one receiving a Y will develop into a male (XY)
Either of a pair of chromosomes in diploid cells, or a single chromosome in haploid cells, carrying genes that determine the sex and sex-linked characteristics of an organism. Most mammals, including humans, have one pair of sex chromosomes in diploid cells, designated XX in females and XY in males.
(plural sex chromosomes)