In humans, brown eye color dominates over blue, and the ability to better control the right hand over the left.

In humans, brown eye color dominates over blue, and the ability to better control the right hand over the left. A blue-eyed right-hander, heterozygous for the second trait, married a brown-eyed left-hander, heterozygous for the first trait. What phenotypic offspring can be expected among their children?

Let’s designate the gene responsible for brown-eyed as C, then the blue-eyed gene will be designated as c.

Let’s designate the gene for predominant right-handedness as P, then the gene for left-handedness will be p.

Blue-eyed right-hander – the father, according to the condition, is heterozygous on the second basis. Let’s write it as ssRr. The spermatozoa produced by it will have the form: CP and Wed.

The brown-eyed left-handed mother is heterozygous for the gene for eye color. Let’s write it down as Ссрр, and eggs produced by it as Ср and cр.

The expected offspring of this married couple will look like this:

brown-eyed children with better control of the right hand (CcPр) – 25%;

brown-eyed children with better control of the left hand (Ссрр) – 25%;

blue-eyed right-handed children (ссРр) – 25%;

children with blue eyes and left-handedness (ссрр) – 25%.