Question

A women with blue eyes, a recessive trait, marries a man with brown eyes, the dominant trait. They have children with both blue eyes and brown eyes. Question:
What are the genotypes of the parents?

Complete the genetic cross and describe the ratio of blue to brown eyes among the children.

What are the genotypes of the children?

list what letter is for what please

Answer 1

The children were given the recessive traits from their mother and the dominant traits from their father because the genes mix when they have children.

Answer 2

Answer:

The man is Bb and the woman is bb. The genotype of the children are Bb (brown eyes), Bb (brown eyes), bb (blue eyes) and bb (blue eyes).

Explanation:

Let the allele for blue eyes be represented by b, and the allele for brown eyes  by B.

They have children with both blue eyes (bb) and brown eyes (BB or Bb). Recall that the two alleles in the children are gotten from the parent, one from each. It simply means that both parent have the b allele in their genotype while one of the parent has, at least one B allele.

Hence, the blue eyes parent must have had bb genotype while the brown eyes parent must have had Bb genotype.

Bb  x   bb will produce Bb (brown eyes), Bb (brown eyes), bb (blue eyes) and bb (blue eyes) progeny.

The genotype of the man is Bb and that of the woman is bb while the genotype of the children are Bb (brown eyes), Bb (brown eyes), bb (blue eyes) and bb (blue eyes)