Human Chromosomes
Normally there are 23 pairs of human chromosomes.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, (X/Y)
The combination of X and Y chromosomes determine the sex of the person.
In the middle East, many times a 24th pair of chromosomes come into...