In fruit flies, the color of the eyes is sex linked (on the X chromosome). Complete the cross of the flies in the image to determine the possible offspring produced. (Homozygous white eyed female x red eyed male)
Red eyes are dominant (R), White eyes are recessive (r).
What percentage of the male offspring are expected to have red eyes?
a
100%
b
75%
c
50%
d
25%
e
0%
The inheritance pattern for eye color in fruit flies is sex-linked, meaning it is determined by genes located on the X chromosome. In this case, red eyes (R) are dominant and white eyes (r) are recessive.
The female parent is homozygous for white eyes (rr) and the male parent has red eyes (R). Since the female is homozygous for the recessive white eye allele, all of her offspring will receive a white eye allele from her.
The possible offspring from this cross would therefore be:
- All female offspring will have white eyes (XrXr).
- All male offspring will inherit the red eye allele from their father (XRY), since they receive their X chromosome from the mother and the Y chromosome from the father.
Therefore, 100% of the male offspring are expected to have red eyes.
Answer: a) 100%