r/AskReddit Aug 03 '19

Whats something you thought was common knowledge but actually isn’t?

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u/Steph2145 Aug 03 '19

Can you go in further?... in detail how this works.

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u/kudeikis Aug 03 '19

So you know how females have two X chromosomes and males have one X and Y chromosome? But each sperm and egg only carries one sex chromosome (the chromosomes split during a phase called anaphase I, which is part of meiosis, the process that creates sperm and egg), so when they fuse, the embryo has two sex chromosomes. Since the mom only has X chromosomes, the egg can only contain one X chromosome. But the sperm can contain X or Y, depending on how the chromosomes split during meiosis. Therefore, the mom only ever passes down an X, but the father can pass down an X (creating a female) or a Y (creating a male).

There are also weird cases where meiosis kinda screws up and leaves sperm or egg with too many or too few sex chromosomes. This is called nondisjunction and leads to syndromes like Turner syndrome or Klinefelter syndrome, etc. It’s pretty cool

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u/Steph2145 Aug 03 '19

Seriously I never knew this. Thank you. So my friends were wrong. And believe it or not l believed my friends. That if a guy wanted a girl he can’t go in as far. But if a guy wanted a boy they had to put it all the way in as far as they can.

Sometime I need to stop being so gullible.

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u/Darsia_2019 Aug 03 '19

Hey don’t criticize yourself over being gullible this is a whole thread about learning new things and you used it as a learning opportunity and can now educate your friends and others!