Question

What are the genotypic and phenotypic distributions for the F1 and F2 generations from a cross between a chick with black (BB) feathers and chicken with white (WW) feathers if the color is determined by alleles that show codominance. The heterozygote is an erminette chicken, which is black and white speckled.

Answer 1

Answer:

Please find the punnet square to this question as an attachment

F1 generation:

genotype = BW

Phenotype = Erminette offsprings

F2 generation:

genotype = BB (1): BW(2): WW(1)

Phenotype = 1 Black, 2 Erminette, 1White

Explanation:

This question involves a gene coding for feather color in chickens. The allele for black feathers (B) is codominant with the allele for white feathers (W) to form an erminette chicken (black and white speckles).

According to this question, a cross between a chick with black (BB) feathers and chicken with white (WW) feathers will result in an all erminette chicken (BW) in the F1 generation (see attached image)

Also, in the F2 generation got by self-crossing the Erminette genotype in the F1 generation (BW), the following genotypic and phenotypic ratios are observed:

Genotypic ratio = BB (1): BW(2): WW(1)

Phenotypic ratio = 1 Black, 2 Erminette, 1White