Ok? Would you link something that proves this fact wrong? Its in a textbook because its a universally accepted scientific fact.
What, that sex chromosomes exist? How exactly does that have anything to do with what is being discussed here? Turns out that human development is a lot more complicated than elementary school genetics.
Scientific fact is kinda a silly phrase. The only "facts" are data, not the conclusions generated by them, and even then data has uncertainty around it.
*insert list of known chimeras here, insert list of fish that change sex and can procreate as either here, etc.*
*insert list of hum- oh wait this isnt possible
Human chimeras have been recorded. *laughs* some bioengineer you are.
Not a single human chimera has been able to have both sexes. Unlike the lab rats you are citing. If you were honest and not merely pushing a narrative, you would know that human chimeras are from blood transfusions or absorbing a dead twin fetus. Neither of which would lead to a transgender.
Quoth the raven
Oh wait that joke doesn't work here
Says the guy who works at fed ex and used a picture from a kid's text book
A) I dont work there B) its in a textbook because its a basic scientific fact. Thats not really helping your case. C) ---