Answer to Question #162276 in Biology for Anas

Question

Problem II: Yellow seed colour is dominant to green seed colour and Axial flowering

plants are dominant to terminal flowering plants. If a Heterozygous yellow terminal

plant is crossed with a green heterozygous axial plant what are the Genotypic an Phenotypic ratios of the first generation ?

Answer 1

Y - yellow seed allele,

y - green seed allele,

A - axial flowering allele,

a - terminal flowering.

The genotype of a heterozygous yellow terminal plant is Yyaa. The possible gametes are Ya and ya.

The genotype of a green heterozygous axial plant is yyAa. The possible gametes are yA and ya.

Following the cross, the possible genotypes and their frequencies in the first generation are:

25% YyAa, 25% Yyaa, 25% yyAa, 25% yyaa.

As a result the possible phenotypes are: yellow axial (25 %), yellow terminal (25 %), green axial (25%) and green terminal (25 %).