Yellow-seeded pea plants may be homozygous or heterozygous. To find out which, cross the plants with
A) heterozygous yellow-seeded plants.
B) true-breeding yellow-seeded plants.
C) heterozygous green-seeded plants.
D) true-breeding green-seeded plants.
E) the same genotype.

Question

Quizplus · Accepted Answer

To determine if yellow-seeded pea plants are homozygous or heterozygous, crossing them with true-breeding green-seeded plants (D) is the most effective method. True-breeding green-seeded plants are homozygous recessive for the seed color trait. If any offspring from this cross are green-seeded, the original yellow-seeded plant must have been heterozygous, carrying one allele for yellow and one for green. If all offspring are yellow-seeded, the original plant is likely homozygous for the yellow seed color allele. This method utilizes the principle of a test cross, where an individual of unknown genotype is crossed with a homozygous recessive individual to reveal the unknown genotype based on the phenotypes of the offspring.

Yellow-Seeded Pea Plants May Be Homozygous or Heterozygous