Question

A horticulturist is breeding a new variety of houseplant in which two genes control leaf color. G (allele for green) is dominant to g (yellow) and B (second allele for green) is dominant to b (yellow). The recessive homozygous condition of either gene will mask a dominant allele. What color is a plant with the genotype Ggbb?

A. An intermediate yellow-green
B. Yellow
C. Variegated (yellow and green spots or stripes)
D. Green
E. The color cannot be determined with the information given.

Answer 1

A plant with the genotype Ggbb will be yellow in color, as the homozygous recessive condition (bb) masks the dominant green allele. The correct answer is B.

Step-by-step explanation:

The question involves a plant with the genotype Ggbb. According to Mendelian genetics, G (green) is dominant to g (yellow) and B (green) is dominant to b (yellow). However, the condition here is that the recessive homozygous condition of either gene will mask the presence of a dominant allele. Since the genotype Ggbb includes a homozygous recessive pair for the second gene (bb), the dominant green allele G is masked, resulting in the plant having a yellow leaf color. Thus, the color of the plant with the genotype Ggbb is yellow (option B).