A: On 12 September 2001, less than 24 hours after the terrorist attacks against the United States, NATO declared the attacks to be an attack against all NATO member countries within the terms of Article 5 of the North Atlantic Treaty.
Humans have an additional pair of sex chromosomes for a total of 46 chromosomes. The sex chromosomes are referred to as X and Y, and their combination determines a personâs sex. Human females have two XX chromosomes while males possess an XY pairing.
A femaleâs two X chromosomes also have the same genes arranged in the same order. So females have two copies of every gene, including the genes on sex chromosomes. The X and Y chromosomes, however, have different genes. So for the genes on the sex chromosomes, males have just one copy. The Y chromosome has few genes, but the X chromosome has more than 1,000. Well-known examples in people include genes that control color blindness and male pattern baldness.