Question

In corn plants the allele for green kernels (G) is dominant over clear kernels (g). Cross a homozygous dominant plant with a homozygous recessive plant. Fill in the Punnett square below and give the ratios for each question beneath the Punnett square

Answer 1

1. Genotypic ratio of the offspring = 100% Gg
2. Phenotypic ratio of the offspring = 100% green kernels

This cross involves a monohybrid crossing. A monohybrid cross involves the mating of individuals that differ in only one trait. This cross helps examine the inheritance of a single gene and its variants (alleles) from one generation to the next. The Punnett square is a common tool used to predict the genotype and phenotype ratios of offspring resulting from a monohybrid cross.

In this case:

• Parent 1 genotype = GG
• Parent 2 genotype = gg

Crossing the two parents in a monohybrid crossing:

G G

g Gg Gg

g Gg Gg

The genotypes above can be used to fill a 2 x 2 Punnet's square accordingly.

Assuming green kernels (G) is dominant over clear kernels (g).

• The genotypic ratio of the offspring = 100% Gg
• The phenotypic ratio of the offspring = 100% green kernels