Eyeless is a recessive gene on chromosome 4 of Drosophila melanogaster. Flies homozygous for ey have tiny eyes or no eyes at all. A male fly trisomic for chromosome 4 with genotype + / +/ey is crossed with a normal, diploid eyeless female.

What proportion of their progeny will be eyeless?

A. 1/6

B. 1/3

C. 1/2

D. 2/3

E. 1/8

F. 1/4

G. 3/8

H. 5/8

I. 3/4

Question

Biology

Adrianna Decker

27 January, 03:24

Eyeless is a recessive gene on chromosome 4 of Drosophila melanogaster. Flies homozygous for ey have tiny eyes or no eyes at all. A male fly trisomic for chromosome 4 with genotype + / +/ey is crossed with a normal, diploid eyeless female.

What proportion of their progeny will be eyeless?

A. 1/6

B. 1/3

C. 1/2

D. 2/3

E. 1/8

F. 1/4

G. 3/8

H. 5/8

I. 3/4

+1

Answers (1)

Know the Answer?

Landin · Answer 1

A. 1/6

Explanation:

A male fly trisomic for chromosome 4 with genotype + / +/ey is crossed with a normal, diploid eyeless female. i. e

δ + / +/ey ey/ey ⊕

+, +, + / +, ey, + / ey, + / ey * ey/ey

ey/+, + / ey, + / +/ey, ey/ey, + / ey/ey, + / ey/ey

ey/+, + / ey, + / +/ey, ey/ey, + / ey/ey, + / ey/ey

=2/12

=1/6