PATHOLOGY

Detailed explanation-1: -The sex chromosomes form one of the 23 pairs of human chromosomes in each cell. The X chromosome spans about 155 million DNA building blocks (base pairs) and represents approximately 5 percent of the total DNA in cells. Each person normally has one pair of sex chromosomes in each cell.

Detailed explanation-2: -X chromosome: Humans and many other mammals have one pair of sex chromosomes in each cell. Females have two X chromosomes, while males have one X and one Y chromosome.

Detailed explanation-3: -An egg or sperm only has half of the parent’s sex chromosome pair. An egg will always have an X chromosome, since the woman’s sex chromosome pair only has Xs. Sperm can have either an X chromosome or a Y chromosome. If a sperm with an X chromosome fertilizes the egg, the new cell will have two X chromosomes.

Detailed explanation-4: -The X chromosome has about 2, 000 genes, whereas the Y chromosome has fewer than 100, none of which are essential to survival. (For comparison, the smallest autosome, chromosome 22, has over 500 genes.) Virtually all of the X chromosome genes are unrelated to sex. Only the Y chromosome contains genes that determine sex.