Question

The diagram below is of a Punnett square for the cross between two heterozygous flowers, Rr and Rr.

Image

Assuming the flowers in this cross display complete dominance, and the allele, R, is dominant for a red pigment and the allele, r, is recessive for a white pigment, what percent of the offspring will have red flowers?

A.
25%

B.
50%

C.
75%

D.
100%

Answer 1

C. 75%

Crossing Rr × Rr gives genotypes RR, Rr, Rr, rr. With R dominant, RR and Rr are red (3 out of 4), so 75% of offspring are red.