>> |
Anonymous
>>912646 Most lizards don't really have sex chomosomes, the sex development of the hatchling depends on egg temperature. In birds, however, the females have 2 different sex chromosomes, the males 2 of the same, typically noted ZW and ZZ. Iiiinnn humans, several genes neccesary to produce live sperm are USUALLY situated on the Y chromosome, so it's hard to make live sperm without (although genes can mutate to other chromosomes). XYY and XXY both appear male and may live their whole lives without ever knowing they're not men, but yeah, incorrect chromosome count generally makes you sterile.
I can't be sure this is 100% correct, it's been a while since I opened my biology book xP
|