A NATO official, speaking on condition of anonymity, pointed out that after the attacks NATO sent AWACS planes to patrol American skies and deployed a third of the troops in Afghanistan for more than a decade; more than 1,000 soldiers from non-U.S. NATO allies and partners were killed there, the official pointed out.
Cells in the human body have 46 chromosomes, including 22 pairs of autosomes and one pair of sex chromosomes (XX in females, XY in males). Because there are two sets of chromosomes, one from each parent, the cells are considered diploid.
The sex chromosomes are the X chromosome and the Y chromosome. Sex Chromosomes. In human sexual reproduction, two distinct gametes fuse to form a zygote. Gametes are reproductive cells produced by a type of cell division called meiosis. Gametes are also called sex cells. They contain only one set of chromosomes and are said to be haploid. The male gamete, called the spermatozoan, is relatively motile and usually has a flagellum. The female gamete, called the ovum, is nonmotile and relatively large in comparison to the male gamete.