Why are se-linked traits such as red-green color blindness N hemophilia more commonly found in boys than grl?

Question

plz help the d**n teacher didn't explain for S**t heh

Answer 1

The trait is linked to the X chromosone. Females have one, males two. So if the mom is a carrier (she has two x's, one has the trait) she will give one x to the baby boy and he has no other x to counteract it the way baby girl does

Answer 2

because if a girl has one defective X from a parent the other X can take over for it. if a boy has a defective X it is the only one they have.  girls are XX and boys are XY.  does this make sense if not i can explain it more thoroughly

Answer 3

These disorders have their genes located on those parts of the X-chromosome that has no corresponding part on the Y-chromosome. A female needs two of these genes, one on each X-chromosome, to be affected. A male needs only one (on the X-chromosome) to be affected. Therefore, females have 50% less chance of contracting these disorders, but they can be genetic carriers.

Answer 4

s*x linked traits are on the X chromosomes so a female (XX) could have one recessive allele on one X and one normal dominant allele on the other X and although she would be a carrier for the recessive allele her phenotype would be normal.

Males on the other hand are XY and so are either normal or have the recessive allele - they cannot be carriers.

Answer 5

Probably the simplest answer is this:  Because those genes only need one single copy of themselves to become expressed in males.  In females, they require two copies of the gene for them to be expressed.

Boys have an X and a Y chromosome...think of the Y chromosome as a smaller X chromosome with fewer genes.  Two of the genes that are usually missing on the Y chromosome are the ones that control color blindness and haemophilia.  So, in effect, if the male has one defective gene for these traits on the X chromosome, there is NO counterpart on the Y chromosome to counteract the effect of the bad gene.

In females, since there's two X chromosomes, there is still a chance that one of the two genes for color blindness or haemophilia will be a good gene and will take precedence.

I hope this helps.