Brown eyes is dominant to green eyes. Blue eyes is recessive to all eyes. Kate has green eyes (Her mother had brown eyes and her father had blue eyes). She marries Tom, who has brown eyes (his mother had blue eyes and his father had brown eyes). What are the odds that their child will have blue eyes?

There is a possibility that 1 in 4 progeny or 25% progeny is blue eyed.

Explaination:

Given in the question:

Dominant eye color is brown

Recessive to brown is green

blue is recessive to both green and brown

Kate = green eyes (mother brown eyed X father blue eyed)

The gey gene has two alleles one of blue and other of green.

Thus genotype of mother was Bbgreen

genotype of father bb

Bbgreen X bb

Bb bb bgreeb bgreenb  Kate's genotype

genotype of kate = bgreenb

Tom = brown eyes (mother blue eyed X father brown eyed)

            bb X BB

Tom, genotype is Bb

Cross between Tom and Kate

Bb X bgreenb

Punnet square shows that:

                 B           b

bgreen   Bbgreen bgreenb

b             Bb              bb

phenotype ratio

2 brown: 1 green: 1 blue

25% progeny is blue eyed.

the real answer is b. scintillation counter