Question

A pea plant heterozygous for inflated pods (Ii) is crossed with a plant homozygous for constricted pods (ii). Draw a punnet square for this cross to predict genotypic and phenotypic ratios. Assume that pollen comes from the ii plants.

Short answer

The cross is made between the Ii*ii that give rise to an offspring with a genotypic ratio of 1:1. The phenotypic ratio of this cross gives rise to 1 inflated plant and one constricted plant leading to the ratio of 1:1.

Step-by-step solution

Description of homozygous and heterozygous

The homozygous conditions are the presence of identical alleles within a particular locus. The heterozygous condition is the presence of two different alleles present within the same gene.

In this given condition, the crosses are made between the homozygous pod and heterozygous pod.

Description of genotype and phenotype

Organisms can possess traits that can be divided into genotype and phenotype. Genotype is the presence of a set of genes in an organism. Phenotype refers to the traits that are observable in an organism.

Punnet square for the cross between the inflated pods and constricted pods

The punnet square for this condition is as follows:

	I	i
I	Ii	Ii
i	ii	ii

The cross between the inflated and constricted pod gives rise to a genotype Ii: ii. The genotypic ratio for this condition is 1:1, and the phenotypic ratio for this condition is 1:1. The phenotypes formed are one inflamed and one constricted.

Hence, there is an equivalent ratio seen between the inflated and constricted pods as 1:1.