A genetic cross between two F1-hybrid pea plants for
spherical seeds will yield what
percent spherical-seeded plants in the F2 generation? (Recall, spherical-shaped seeds are dominant over dented seeds.)
Crossing two heterozygotes
The parent plants are heterozygous for an allele that determines seed
shape. We can use a Punnett square to predict the phenotypes of their offspring.
The F1-hybrid plants have the dominant (S), spherical seed phenotype. In the Punnett square, we see that one out of four possible combinations of F2-generation plants has the homozygous recessive genotype (ss).