Sex determination in humans, you are probably
all fairly familiar with the female has a
possibility of contributing X and X and the
male could contribute and X or a Y. And the Y
chromosome is a little bit special. First
of all, it is tiny, but it also has a gene
on it that is involved in sex determination.
It is called the SRY region of the Y chromosomes.
It is the sex-determining region of the Y
chromosome. And if that gene is present and
expressed, then we will see maleness, but
if that gene is not present maybe there is
no Y chromosome or maybe the gene is broken,
then by default we will see the female phenotype
in human condition. We know how this works
out. We have an X and a Y. We can have male
progeny or X is in excess, we have female
progeny. Fifty percent chance of boys or girls
based on this sex determining system.