Question

Among pea plants, we see more peas with smooth pods than with constricted pods. If a plant with constricted pods is mated with a plant with smooth pods, the offspring have smooth pods. When the offspring mature, and two of them are mated, they have a 25 percent chance of producing offspring with constricted pods. Identify the offspring with homozygous alleles for the smooth pod trait.

Answer 1

Assume that the allele for smooth pod is denoted by Letter R and that of constricted pod allele is denoted by letter r. The mated offspring are heterozygous for pod texture. When heterozygous pea plants are mated, the offspring is as shown in the following punnet square;

Homozygous recessive = 25%

Heterozygous offspring = 50%

Homozygous dominant – 25%