The gene for blue eyes is recessive. If your mother has blue eyes and your brown-eyed father has one gene for blue eyes and one for brown eyes, what are your chances of having blue eyes?
Answer
This looks like a simple Punnett square that you should be familiar with. What we know:
bb is homozygous recessive for blue eyes
Bb is heterozygous for brown eyes
BB is homozygous dominant for brown eyes
b b (mother)
B Bb Bb
b bb bb
(father)
The cross equals 50% heterozygous for brown eyes and 50% homozygous recessive for blue eyes.