Mendel found that green pea pod color (y) was recessive to yellow pea pod color (Y). For the cross Yy × yy, what percentage of offspring are expected to be yellow?

• A. 100%.
• B. 75%.
• C. 50%.
• D. 25%.

Answer: (C)

Verified step by step guidance

1. Identify the genotypes of the parents: Yy (heterozygous yellow) and yy (homozygous green).
2. Set up a Punnett square to determine the possible genotypes of the offspring. Place one parent's alleles (Y and y) on the top and the other parent's alleles (y and y) on the side.
3. Fill in the Punnett square by combining the alleles from each parent. The possible genotypes for the offspring are: Yy, Yy, yy, and yy.
4. Determine the phenotype associated with each genotype. Yy results in yellow pea pods because the yellow allele (Y) is dominant, while yy results in green pea pods.
5. Calculate the percentage of offspring with yellow pea pods. Since 2 out of the 4 possible genotypes (Yy) result in yellow pea pods, the expected percentage of yellow offspring is 50%.