Question

In peas, yellow seed color (y) is dominant to green seed color (y). a homozygous green seed pea plant is crossed with a heterozygous yellow seed pea plant. what is the predicted phenotypic ratio of the offspring based on seed color?

Answer 1

The predicted phenotypic ratio of the offspring based on seed color in this cross is 100 percent yellow seeds.

Step-by-step explanation:

The predicted phenotypic ratio of the offspring based on seed color in this cross can be determined using Punnett square analysis. In this case, the homozygous green seed pea plant can be represented by the genotype yy, while the heterozygous yellow seed pea plant can be represented by the genotype Yy. When these genotypes are crossed, the possible genotypes of the offspring are YY and Yy.

The phenotypic ratio of the offspring can be determined by looking at the expression of the dominant yellow seed color (Y) and the recessive green seed color (y). Since yellow seed color is dominant over green seed color, all offspring with at least one Y allele will have yellow seed color. Therefore, the predicted phenotypic ratio of the offspring based on seed color in this cross is 100 percent yellow seeds.

Answer 2

The predicted phenotypic ratio of the offspring is 4:0 for yellow seed color.

To predict the phenotypic ratio of the offspring based on seed color in a cross between a homozygous green seed pea plant (yy) and a heterozygous yellow seed pea plant (Yy), you can use Punnett squares. Here are the steps:

1. Determine the genotypes of the parent plants:

- Homozygous green seed pea plant (parent 1): yy

- Heterozygous yellow seed pea plant (parent 2): Yy

2. Set up a Punnett square to cross these two parent genotypes

Parent 1 (yy)

↓

Parent 2 (Yy)

3. Fill in the Punnett square by combining the alleles from each parent:

Parent 1 (yy)

↓

Parent 2 (Yy)

--------------

Yy | Yy

Yy | Yy

4. Analyze the genotypes of the offspring:

- 4 offspring genotypes are Yy (heterozygous yellow seed).

5. Determine the phenotypes based on the genotypes:

- Yy genotypes result in yellow seed color.

6. Calculate the phenotypic ratio by counting the number of each phenotype:

- Yellow seed (Yy): 4

Now, you have the phenotypic ratio of the offspring based on seed color:

- Yellow seed (Yy): 4

Since there are no green seed alleles (yy) in the offspring, they will all have yellow seed color, as yellow (Y) is dominant to green (y).