If a man and a woman produce a colorblind son, which of the following MUST be true?

Question

**Background info: in humans, red-green color blindness is a sexlinked recessive trait.**
(A) The father is colorblind
(B) Both parents carry the allele for color blindness
(C) Neither parent carries the allele for color blindness
(D) The father carries the allele for color blindness
(E) The mother carries the allele for color blindness

Answer 1

E, the father doesn't need to be color blind because color blindness is X linked and he'd give his Y chromosome to his son. Mom doesn't have to be color blind because only 1 color blind X chromosome is needed in a male. There's no other X in the son to 'cover it up' as in a female. Mom can be color blind, but doesn't have to be.

Answer 2

E. The mother carries the allele for color blindness. Color blindness is a sex-linked disease which located in X chromosome. The colorblind son inherited the X which carries the color blind gene from his mother. The father contributes only Y chromosome and it got nothing to do with the color blindness of his son

Answer 3

Letter E. The mom was hybrid for that trait and passed on the recessive gene to her son. The father could not pass on an X chromosome so he could not give the child a gene for colorblindness.

Answer 4

If it's sex linked, it's on the X chromosome. The son got that from his mom. So the answer is E, the mom carries the allele (she doesn't express it because she has another X chromosome without the allele)

Answer: E

Answer 5

the mother has to be a carrier. my dad is colorblind. i know.

Answer 6

I think the answer is E.

Answer 7

F. They had sex

Answer 8

E