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Punnet square for cross between brown and blue eye color

In humans, brown eyes (B) are dominant over blue (b)*. A brown-eyed man marries a blue-eyed woman and they have three children, two of whom are brown-eyed and one of whom is blue-eyed.

Draw the Punnett square that illustrates this marriage.

What is the man's genotype?

What are the genotypes of the children?

(* Actually, the situation is complicated by the fact that there is more than one gene involved in eye color, but for this example, we'll consider only this one gene.)

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The couple have children with eyes of both brown and blue color.

The dominant trait is the brown eye color, so denoted as B.

The recessive trait is blue eye color, hence denoted as b.

The woman has blue eye color, so her genotype should be 'bb'.

If the man ...

Solution Summary

This solution deals with Mendelian inheritance for the eye color in humans. It gives the outcome for the cross of brown eyed man and blue eyed woman. It deals with the construction of the Punnet square for the same and determination of the genotype of the man as well as the children.