Question

Black hair is homozygous dominant. Brown hair is heterozygous. Blonde hair is homozygous recessive. (This is an example of incomplete dominance.)

What is the genotype for black hair?
What is the genotype for brown hair?
What is the genotype for blonde hair?

A woman with brown hair marries a man with brown hair.
What are the possible phenotypic outcomes for their kids? (Give the response as percentages)
What are the possible genotypic outcomes for their kids? (Give the response as percentages)

Answer 1

Step-by-step explanation:

Black hair genotype-AA

Brown hair-Aa

Blonde-aa

P Aa×Aa

⬇️ ⬇️

F1 A a => Aa(brown) 100%

F2 A a

A AA Aa

a Aa aa

25% black:50%brown:25%blond

1:2:1 genotype

Answer 2

Genotype of black hair: BB

Genotype of brown hair: Bb

Genotype of blonde hair: bb

Phenotypic outcomes of their kids:

• Black hair color 1/4 = 25%
• Brown hair color 1/2 = 50%
• Blonde hair 1/4 = 25%

Genotypic outcome for their kids:

• BB = 25%
• Bb = 50%
• bb = 25%

Step-by-step explanation:

Let the allele for hair color be represented by B.

Since black hair color is homozygous dominant, the genotype will be BB

Blonde hair color is homozygous recessive, the genotype will be bb

Brown hair color is heterozygous, the genotype will be Bb

A woman with brown hair (Bb) marries a man with brown hair (Bb)

Bb x Bb

Progeny: 1 BB (black), 2 Bb (brown), 1 bb (blonde)

Phenotypic outcomes of their kids:

• Black hair color 1/4 = 25%
• Brown hair color 1/2 = 50%
• Blonde hair 1/4 = 25%

Genotypic outcome for their kids:

• BB = 25%
• Bb = 50%
• bb = 25%