In pea plants, the allele for round seeds is dominant to the allele for wrinkled seeds. if a plant that is heterozygous for seed type is crossed with one that has only homozygous wrinkled seeds, what percent of their offspring would you expect to have wrinkled seeds?
100 percent
50 percent
25 percent
0 percent

The correct answer would be 50 percent.

Let us assume R and r be the alleles of the gene responsible for the shape of the seed.

R is the dominant allele which leads to the formation of round shaped seeds while r is the recessive allele which leads to the formation of wrinkled shaped seeds when present in homozygous condition.

Now, the genotypes of the parent plants are Rr (heterozygous) and rr (homozygous recessive).

Gametes produced by Rr would be R and r.

Gametes produced by rr would be r only.

The cross is shown in the figure attached below.

It resulted in the formation of offspring with two types of genotypes Rr (round shaped seeds) and rr (wrinkled shaped seeds) in equal proportions.

Hence, we can conclude that 50 percent of the offspring are expected to have wrinkled seeds when heterozygous for seed type is crossed with one that has only homozygous wrinkled seeds.