The number of chromosomes varies, but is constant and its specific type. In all chromosomes somatic cells found in pairs. Thus a person owns 23 pairs of chromosomes means a total of 46 chromosomes. Chromosomes of a pair of homologous chromosomes mark as originating in one of the other father of the mother. However, the masculine and feminine it, chromosomes of a couple distinguish between them by symbols. They male marked with signs x, y while those feminine marked with signs x, x. Chromosomes of this couple to couple respectively 23, call the sex chromosomes, while the other 22 chromosomes autozomale couples.
