However, these females are sterile and that's because that second X sex chromosome is needed to actually fully develop the ovaries. And so these individuals are basically sterile because they do not have developed fully developed ovaries and fully developed female genitalium. Now let's move on to the final type of sex chromosome abnormality, the XYY. Now, unlike the XXY and the XO, this is not actually a syndrome because individuals that have this type of caraotype live normal lives and they don't really have too many abnormalities. They have a normal phenotype and they are fully fertile. So suppose that instead of combining sperm cell number four we took sperm cell number three.