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.
Picture 1: Genes, chromosomes and DNA. The chromosomes (see Picture 2) numbered 1 to 22 look the same in males and females. These are called the autosomes. Pair number 23 is different in males and females and they are called the sex chromosomes. There are two kinds of sex chromosome, one called the X chromosome and one called the Y chromosome.