As it happens, humans have 23 pairs of chromosomes. Of those, 22 pairs are known as
autosomes, and are inherited the same way in men and women. The remaining pair are known as the
sex chromosomes, because they’re inherited differently in men and women.
If you have two “X”-shaped sex chromosomes, you’re a female. If you have an “X” chromosome plus a smaller “Y” chromosome, you’re a male. You may have noticed that a woman can give
only an “X” chromosome to her child, but a man can give his child either an “X” or a “Y” chromosome. Therefore, it’s the father’s genetic contribution that determines the sex of a child.

The 23 pairs of homologous chromosomes in a human. The autosomes are
the 22 pairs that do not differ between males and females. The last pair
are the sex chromosomes. A female has two "X" chromosomes, whereas a
male has a single "X" chromosome and a smaller "Y" chromosome.