Question

A mating between individuals who are heterozygous for two genes of interest

Using the Punnett Sq, predict the phenotypic ratios in the offspring that result from a cross of two pea plants that are heterozygous for both seed color and shape.
(YR, Yr, yR, yr X YR, Yr, yR,yr)

Answer 1

The phenotypic ratios in the offspring resulting from a cross of two heterozygous pea plants for seed color and shape will be approximately 5:3.

Step-by-step explanation:

A Punnett square can be used to predict the phenotypic ratios in the offspring resulting from a cross of two pea plants that are heterozygous for both seed color and shape. In this case, the parental genotypes are YR, Yr, yR, and yr.

When we cross these parents and use a Punnett square, we can see that the potential genotypes of the offspring are YYRR, YYRr, YYrR, YYrr, YyRR, YyRr, YyrR, and Yyrr. Based on these potential genotypes, we can determine the phenotypic ratios by examining the expression of the dominant traits, which are yellow seed color and round shape.

Using the sum rule of probability, we can observe that the genotypes YYRR, YYRr, YYrR, YyRR, and YyRr will result in offspring with yellow seeds and round shapes.

Therefore, the phenotypic ratio of yellow and round seeds to other phenotypes is 5:3. Thus, the phenotypic ratios in the offspring would be approximately 5 yellow and round seeds : 3 other phenotypes (either yellow and wrinkled seeds, green and round seeds, or green and wrinkled seeds).