How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous?

Question

View Available Hint(s)for Part A

Cross the green-pod plant with another green-pod plant.
Cross the green-pod plant with a yellow-pod plant.
Self-pollinate the green-pod plant.

Answer 1

To determine whether the genotype of the green-pod plant is homozygous or heterozygous, the best approach would be to cross the green-pod plant with a yellow-pod plant.

Here’s why this method is effective:

1. Homozygous Green-Pod Plant: If the green-pod plant is homozygous (e.g., GG), all offspring from the cross with a yellow-pod plant (assuming the yellow-pod plant is homozygous for the yellow trait, gg) would show the green phenotype (Gg), since green is dominant over yellow.

2. Heterozygous Green-Pod Plant: If the green-pod plant is heterozygous (Gg), the offspring would show a 1:1 phenotypic ratio: approximately half would show the green phenotype (Gg) and half would show the yellow phenotype (gg).

By examining the phenotypes of the offspring from this cross, the botanist can infer the genotype of the green-pod plant: if all offspring are green, the parent is homozygous; if there is a mix of green and yellow offspring, the parent is heterozygous.