I am the random fact lady. For some reason my brain just retains these little snippets of information so I can pull them out of thin air at a moments notice.
There's one that has been sitting on my mind I want to share that really I am surprised we aren't taught about more in school. I did not learn of it til I got into college and took a Reproductive and Physiology course (the same semester I also took Embryology and Breeding, it was a hard time for my husband).
Everyone defaults to female. It is the reason that both sexes have an X chromosome but you only find the Y in males (women have double X because the extra X goes through chromosomal silencing. It is never expressed).
It is the Y chromosome that contains genes encoding for a special enzyme. This enzyme then converts testosterone into a different hormone that causes a change in an early embryonic organ called the wollfian duct. This duct in the presence of secondary testosterone then turns into the male reproductive organs.
While female embryos with no secondary testosterone hormone have their wollfian duct form down a different path and create the female reproductive organs. So it is only with this override of a hormone that you get what is traditionally considered male.
This means that when we were all conceived each of us, regardless of what gender we are now, would be considered women.
Makes the differences between men and women seem a whole lot smaller now, doesn't it?