Question

Fifty percent of the offspring produced by a cross between pea plants have seeds with a wrinkled (r) appearance caused by the presence of a homozygous recessive gene. What were the genotypes of the parents? A. Rr × Rr B. Rr × rr C. RR × Rr D. RR × rr

Answer 1

The correct option is B. Rr × rr

Explanation:

To illustrate the results, lets make a cross between RR and rr.

r r

R Rr Rr

r rr rr

The results from the following punnet square show that there will be a 50% probability that the offsprings will have heterozygous genotype Rr and they will be round.

The results from the punnet square show that there will be a 50% probability that the offsprings will be recessive and hence will have wrinkled seeds.