A s*x trait on an X chromosome carried by the mother will be expressed in the son about half of the time why?

Question

A s*x trait on an X chromosome carried by the mother will be expressed in the son about half of the time why?

Answer 1

Women have two X chromosomes and unless all are carrying for this genetic trait...as in she recieved it from both parents...it would only be incoded on half of her eggs, thus only half the time would it show up.

Answer 2

50/50.

Answer 3

That's not necessarily true.  It depends on a few things, like is the trait dominant or recessive?  Does it require a double gene to be expressed?  If a gene is expressed only half the time, it would have to be one that the mother carries both as dominant and recessive, which would mean that when the zygote splits, only one egg will get the gene.  And the father would also have to carry it the same way, with half the sperm carrying the gene.  Otherwise, you would either have the gene expressed all the time or it might only be expressed one time out of four.  And when you say a "s*x trait", do you mean gender or sexual characteristic?

Answer 4

Assuming that the mother is only carrying a the s*x trait on one of her own X chromosones, then it will be passed on half the time, here's a link...

http://www.nearingzero.net/screen_res/nz...

Hehe