AP BIOLOGY

Detailed explanation-1: -∙ Selfing of the F1 plants gave F2 progenies exhibiting 4 different phenotypes: Round yellow (9), wrinkled yellow (3), round green (3), and wrinkled green seeded plants (1). Hence, the phenotypic ratio is 9:3:3:1.

Detailed explanation-2: -RR or Rr is the dominant genotype responsible for round seeds. YY or Yy is the dominant genotype responsible for yellow seeds. rr is the recessive genotype responsible for wrinkled seeds. Hence the seed that has the genotype round and green will be RRyy or Rryy.

Detailed explanation-3: -The shape of the pea seeds is controlled by two alleles. S is dominant alleles and stands for smooth and s is recessive allele and stands for wrinkled. The wrinkled phenotype is shown when the genotype contains both the recessive alleles. The genotype of the wrinkled seeds of pea is ss.

Detailed explanation-4: -The phenotypic ratio for F2 generations in a dihybrid cross between purebred round yellow seed pea plants and wrinkled green seed pea plants is 9:3:3:1. This ratio represents the ratio between seeds as round yellow (YR), round green (yR), wrinkled yellow (Yr) and wrinkled green plants (yr).