Color blindness occurs more frequently in males than in females because it is
A) dominant.
B) rare.
C) quite common.
D) a recessive sex-linked trait.
E) both A and B

Question

Quizplus · Accepted Answer

Color blindness is a recessive sex-linked trait, meaning that it is carried on the X chromosome. Females have two X chromosomes while males have one X and one Y chromosome. If a female has one X chromosome carrying the color blindness trait and one X chromosome carrying the normal vision trait, she will have normal vision because the normal vision trait is dominant. However, if a male inherits the X chromosome carrying the color blindness trait, he will express color blindness because he does not have another X chromosome with the normal vision trait to dominate it. Therefore, color blindness occurs more frequently in males than in females due to their sex-linked genetic inheritance.

Color Blindness Occurs More Frequently in Males Than in Females