You cross a pea plant with yellow peas (Yy) and a pea plant with green peas. How many unique genotypes are possible for pea color in the offspring? How many unique phenotypes are possible for pea color in the offspring?

• A. 2 unique genotypes; 2 unique phenotypes.
• B. 3 unique genotypes; 2 unique phenotypes.
• C. 2 unique genotypes; 1 unique phenotype.
• D. 1 unique genotype; 1 unique phenotype.

Answer: (A)

Verified step by step guidance

1. Identify the genotypes of the parent plants. The yellow pea plant has the genotype Yy, where 'Y' is the dominant allele for yellow color and 'y' is the recessive allele for green color. The genotype of the green pea plant is yy, as it must have two recessive alleles to express the green phenotype.
2. Set up a Punnett square to determine the possible genotypes of the offspring. Place the alleles from one parent (Yy) on the top and the alleles from the other parent (yy) on the side.
3. Fill in the Punnett square by combining the alleles from each parent. This will give you the possible genotypes of the offspring. The combinations will be Yy and yy.
4. Count the number of unique genotypes from the Punnett square. In this case, the unique genotypes are Yy and yy, resulting in 2 unique genotypes.
5. Determine the phenotypes associated with each genotype. Yy will result in yellow peas due to the presence of the dominant 'Y' allele, and yy will result in green peas. Therefore, there are 2 unique phenotypes: yellow and green.