In a certain species of plant, flowers occur in three colors: blue, pink, and white. A pure-breeding pink plant is mated with a pure-breeding white plant. All of the F 1 are blue. When the blue F 1 plants are selfed, the F 2 plants occur in the ratio 9 blue : 3 pink : 4 white. The genotype that produces white is ww. The presence of one W allele allows pink or blue color to occur. The alleles at the hypostatic locus are B (blue) and b (pink).
- What is the genotype of the white parent?
A) bb WW
B) bb Ww
C) Bb Ww
D) Bb ww
E) BB ww

Question

Quizplus · Accepted Answer

The white parent must be homozygous recessive for the W allele (ww) to produce white flowers, and since it is pure-breeding, it must also be homozygous for the B locus, hence BB ww.

In a Certain Species of Plant, Flowers Occur in Three