Question

The Punnett square illustrates a cross for flower position in the pea plant. The phenotypes and genotypes of the parents have been given. The allele for axial position is dominant and represented by A. The allele for terminal flower position is recessive and represented by a. What is the genotype of the offspring? Heterozygous homozygous recessive homozygous dominant

Answer 1

Given –

Plant – Pea plant

Character – flower position

Trait – Axial flower (Dominant)

          Terminal flower (Recessive)

Dominant trait is represented by A

Recessive trait is represented by a

I.        In case of Homozygous condition –

Axial flower = AA

Terminal flower = aa

Cross between these two would form:                  

          A        A

a        Aa        Aa

a        Aa        Aa

Phenotype of the offspring = axial flower

Genotype of the offspring = 100% heterozygous dominant with Aa allele

II.        In case of Heterozygous condition –

Axial flower = Aa

Terminal flower = aa

Cross between these two would form:

          A        a

a        Aa        aa

a        Aa        aa

Phenotype of the offspring = 50% axial flower, 50% terminal flower

Genotype of the offspring = Axial flower with genotype Aa

                                               Terminal flower with genotype aa