What Student Need to Know about Structural Abnormalities Involving Human Chromosomes

DNA molecules are tightly wrapped around proteins called histones, nonhistone proteins that make structures called chromosomes, and are present in the cell nucleus as unconcentrated during the cell cycle. Chromosomes are structures inside cells that contain an individuals genes. The human genomes have 46 chromosomes, composed of 22 pairs of autosomes and a pair of sex chromosomes (X and, or Y). All of the somatic cells in females carry two X chromosomes, and all of the somatic cells in males carry one X and one Y chromosome. One half of each pair of chromosomes comes from through the egg cells; one half of each pair comes from through the sperm cells. As a result, females carry two copies of each Xlinked gene, while males carry only one copy of Xlinked and Ylinked genes. They vary in size and appearance, the X being much somewhat bigger than the Y and contain entirely separate genes, but they do have small areas of resemblance. Both individuals of a species contain the same number of chromosomes speci