BIOL 1107 Chapter Notes - Chapter 13: Aneuploidy, Trisomy, Somatic Cell
Document Summary
During sexual reproduction, a male reproductive cell (sperm) and a female reproductive cell (an egg) unite to form a new individual, this processing of uniting sperm and egg is referred to as fertilization. During the formation of gametes (reproductive cells such as sperm and egg) there must be a distinctive type of cell division that leads to a reduction in chromosome number. If the sperm and egg contribute to an equal number of chromosomes to the fertilized egg, they must each contain half of the usual number of chromosomes. Then, when sperm and egg combine, the resulting cell has the same chromosome number as its mother"s cells and father"s cells have. Meiosis is nuclear division that leads to a halving of chromosome number and ultimately to the production of sperm and egg. Males have an unpaired set of chromosomes that are x and y, while females lack a y chromosome and instead have two x chromosomes.