In humans, brown-eyed prevails over blue-eyed and right-handedness over left-handedness.

In humans, brown-eyed prevails over blue-eyed and right-handedness over left-handedness. Car-eyed left-handed man marries blue-eyed right-handed woman they will have a blue-eyed left-handed child. Determine the genotypes of the mother, father and child.

Let’s designate the gene that causes the development of brown eyes as A, then the gene that leads, in the homozygous variant, to the development of the blue iris will be a.

Let’s designate the gene for right-handedness as C, then the gene for left-handedness will be c.

A left-handed child with blue eyes will be aass, because homozygosity is a condition necessary for the phenotypic realization of these traits.

To be able to give birth to such a child, his parents must be able to inherit genes for recessive traits, even if they are his latent carriers. In other words, parents should be at least heterozygous for these characteristics.

A brown-eyed left-handed man would then be written like this: Aаcc.

Blue-eyed right-hander – mother: aaCc.