If a female who is a carrier for a sex-linked trait mateswith

a male who expresses the trait, what is the chace that her sonwill

express the trait?

A) 1/4

B) 1/2

C) all of her sons will express the trait

D) none of her sons will express the trait

for lifesaver, explain the reasoning for

youranswer ...

B) 1/2

Explanation:

A sex linked trait is passed via sex chromosomes. Here the given trait is X linked recessive because female carrier is not possible for X linked dominant trait.

For X linked recessive trait:

Carrier female = XCXc

Affected male = XcY

Their progeny:

XC Xc

Xc XCXc XcXc

Y XCY XcY

Out of the sons, half will be not affected (XCY) and half will be affected (XcY)

Hence, half of the sons will express the trait.