Pigment of chicken feathers is regulated by two genes, the gene for feather pigment C, and a gene that inhibits pigment production, I. A mother chicken, who is heterozygous for gene C, and heterozygous for gene I, is crossed with a father chicken, who is homozygous recessive for the pigment gene, and heterozygous for gene. 1) What are the potential haplotypes of the gametes produced by the mother for these two genes?
2) What are the potential haplotypes of the gametes produced by the father for these two gametes?
3) What is the probability of one of the offspring of these two chickens having pigmented feathers?
4) In a population of 100 chickens, produced from the same parents, how many chickens would you expect to have white feathers?

(1)CI Ci cI ci

(2)CI Ci

(3)25

(4)75

Explanation:

Mother is in this case is heterozygous for C & I, genotype of mother would be : CcIi

Father is on other hand is homozygous for C (dominant) and heterozygous for I, genotype : CCIi

1. Gametes produced by the mother will be:

 CI Ci cI ci  by the combinantion of C, I, c, and i alelles present in mothers genotype.

2. Gametes produced by the father :

CI Ci  by the combinantion of alleles present i genotype of father CCIi

3. probability of one of the offspring of these two chickens having pigmented feathers:

 2/8 × 100 = 25% ( punnet is attached)

4. chicken with white feather in population of 100 chickens:

 probability of being white ×  100

probability of being white : 1 - 2/8

thus, (1-2/8) × 100 = 6/8 × 100

    = 75%

the correct answer is d