Question

What would the cross between a plant of genotype RrAa and one of genotype RRaa

Answer 1

The cross between RrAa and RRaa genotypes represent a dihybrid cross because the genes of two traits are simultaneously being considered.

Since characters are not specified here, let's suppose that these are R represent dominant allele for seed shape Round while r represent recessive allele for seed shape wrinkled.

Similarly, A represent the dominant allele of flower color that is yellow while a represents the recessive allele of flower color that is green. (just supposing)

Let's cross them:

P1: RrAa x RRaa

gametes: RA: Ra : rA : ra X RA: Ra : rA : ra

Genotypic ratio

1/16: RRAA Round yellow

2/16: RRAa Round yellow

2/16: RrAA Round yellow

4/16: RrAa Round yellow

1/16: RRaa Round green

2/16: rrAa Wrinkled yellow

2/16: Rraa Round green

1/16: rrAA Wrinkled yellow

1/16: rraa Wrinkled green

You can see attached image for better understanding.

Hope it helps! :)