Answer to Question #162287 in Biology for Anas Bajbouj

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

Let's assume that yellow colour is encoded by the Y allele, green colour is encoded by the y allele, axial flowering is encoded by the A allele and terminal flowering is encoded by the a allele. A genotype of a heterozygous yellow terminal plant is Yyaa and a genotype of a green heterozygous axial plant is yyAa. The gametes are:

Yyaa: Ya and ya.

yyAa: yA and ya.

From here, the genotypes of the offspring are:

YyAa, yellow axial (25 %);

Yyaa, yellow terminal (25 %);

yyAa, green axial (25 %);

yyaa, green terminal (25 %).