Question

In pea plant, round seeds (R) is dominant over wrinkled seeds (r). Yellow colors (Y) are dominant over green color (y). If you cross heterozygous Round, Yellow seed (RrYy) and homozygous Round, Yellow seed (RRYY) what will be the possible phenotype and genotype of the offspring?

Answer 1

When crossing a heterozygous Round, Yellow seed pea plant (RrYy) with a homozygous Round, Yellow seed pea plant (RRYY), all offspring will display Round, Yellow seeds as phenotypes. The possible genotypes are RRYy and RrYy, as these combine the dominant alleles from both parents.

Step-by-step explanation:

In the context of genetics within the study of Biology, when you cross a heterozygous Round, Yellow seed pea plant (RrYy) with a homozygous Round, Yellow seed pea plant (RRYY), you are exploring a dihybrid cross involving two traits: seed shape and seed color. The dominant trait for seed shape is round (R), and the dominant trait for seed color is yellow (Y).

To determine the possible genotypes and phenotypes of the offspring, one can use a Punnett square analysis. We know that the heterozygous plant can produce gametes carrying either R or r for the shape gene and Y for the color gene, while the homozygous plant can only produce gametes with R for shape and Y for color.

When we perform the cross, the possible genotypes for the offspring are: RRYy and RrYy. As for the phenotypes, all of the offspring will display the dominant traits: Round and Yellow seeds, because both R and Y traits are dominant.

This situation shows a simple dominance inheritance pattern where dominant alleles mask the presence of recessive alleles in the phenotype. It also showcases the principle of independent assortment, where alleles for different traits are distributed to gametes independently.