Question

In sheep, eye color is controlled by a single gene with two alleles. When a homozygous brown-eyed sheep is crosses with a homozygous green-eyed sheep, blue-eyed offspring are produced. If the blue-eyed sheep are mated with each other, what percent of their offspring will most likely have brown eyes?
a) 0%
b) 25%
c) 50%
d) 75%
e) 100%

Answer 1

Answer:

b) 25%

Explanation:

let homozygous brown-eyed sheep = bb

let  homozygous green-eyed sheep = gg

bb × gg = bg, bg, bg, bg

         b           b

g       bg          bg

g       bg          bg

If the blue-eyed sheep are mated with each other

i.e  bg × bg  = bb, bg,bg, gg

            b            g

b          bb         bg

g          bg         gg

Therefore , the percentage of bb (which is brown)

= 1/4

=0.25

= 25%