Question

In fruit flies, the allele for white eyes is recessive to the allele for red eyes. In a generation of fruit flies, 45 males with white eyes, 46 females with white eyes, 44 males witIh red eyes, and 47 females with red eyes are produced. Which of the following is the best conclusion you can make about the parents of this generation?
a. One parent was heterozygous for eye color and the other was homozygous with red eyes. Incorrect
b. Both parents were homozygous with red eyes.
c. One parent had white eyes and the other was heterozygous for eye color.
d. Both parents were heterozygous for eye color.

(I know it isnt A)

Answer 1

B should be the right answer

Answer 2

Answer:

C

Explanation:

White eyes (r) are recessive to Red (R).  a) Rr x RR produces 50% RR and 50% Rr, both express with red eyes so there can be no white eyed offspring.   b) RR x RR produces all RR, red eyes so there can be no white eyed offspring.  c) rr x Rr produces Rr, rr, Rr, rr.  50% white, 50% red which is close to the generation given.  d) Rr x Rr produces RR, Rr, Rr, rr: 75% Red, 25% white. not as close to the data as c.