A normal
human cell contains 46 Chromosomes.
We inherit 23 of our chromosomes from
our mother (in the egg), and the other
23 from our father (in the sperm), so
that we have 23 pairs of chromosomes,
and therefore two copies of each gene.
The 23rd pair of chromosomes is referred
to as the sex chromosomes and determines
a person's sex. Females have two X chromosomes
and males have one X and one Y chromosome.
If the sperm contains the father's X,
the baby will be a girl; if he contributes
his Y chromosome, you can expect a boy.
