Question

Hair color is determined in Labrador retrievers by alleles at the B and E loci. A dominant allele B encodes black pigment, whereas a recessive allele b encodes brown pigment. Alleles at a second locus affect the deposition of the pigment in the shaft of the hair; dominant allele E allows dark pigment (black or brown) to be deposited, whereas recessive allele e prevents the deposition of dark pigment, causing the hair to be yellow. A black female Labrador retriever was mated with a yellow male. Half of the puppies were black and half were yellow. If the genotype of the black female parent was Bb Ee, then what was the genotype of the other parent?
a) bb EE
b) BB EE
c) Bb ee
d) BB ee
e) bb ee

Answer 1

Answer:

D) BB ee

Explanation:

As the black pigment is encoded by the allele B.

Brown pigment is encoded by allelle b.

Allele E allows dark pigment to be deposited in the shaft.

Allele e prevents the deposition of pigment in the shaft.

As genotype of the black female is Bb Ee , that means she has a dominant black pigment ( due to presence of allelle B )and is deposited in the shaft (due to allelle E ).

The genotype of the other parent must be BB ee in order to have half of the puppies yellow and the other half being yellow.

All the other options doesn't form the sequence of 50% black and 50% yellow puppies.

The table of probabilities is attached below .