Why are there not more females than males if chromosome pairs split into gametes to be paired up again?

Question

This might not make much sense but I just read that gametes come from XX splitting to X and X and the same for XY into and X and a Y. Assuming these are evenly occurring then there are 75% X and only 25% Y, surely there’s more chance for XX pairs than XY occurring?

In: Biology

Answer 1

The 2 X’s that split can’t join with each other… plus, on the female side, in humans, there’s usually only 1 X allowed per month… and it joins with the 50/50 X-Y splits