Cinnabar eye colour is a sex-linked, recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes?
A) 0%
B) 25%
C) 50%
D) 100%

Question

Quizplus · Accepted Answer

Since cinnabar eye color is a sex-linked recessive trait, and the female has cinnabar eyes, she must be homozygous recessive (X^cX^c). The wild-type male is hemizygous dominant (X^+Y). All F1 males will inherit the X^c from the mother and Y from the father, resulting in 100% of the F1 males having cinnabar eyes.

Cinnabar Eye Colour Is a Sex-Linked, Recessive Characteristic in Fruit