Answer
d. 9:3:3:1
Work Step by Step
When you cross two dihybrid F1 pea plants (AaBb), assuming complete dominance and independent assortment of genes, you would expect a phenotypic ratio in the F2 generation of 9:3:3:1. This ratio represents the following phenotypes:
9 individuals with the dominant phenotype for both traits (A_B_)
3 individuals with the dominant phenotype for the first trait and the recessive phenotype for the second trait (A_bb)
3 individuals with the recessive phenotype for the first trait and the dominant phenotype for the second trait (aaB_)
1 individual with the recessive phenotype for both traits (aabb)
This ratio arises from the different combinations of alleles that can be formed during gamete formation and their subsequent combinations in the offspring due to independent assortment.
