Question

In peas, the allele for yellow seeds (Y) is dominant to the allele for green seeds (y). What would be the genotype and phenotype ratios of offspring from a cross between Yy (heterozygous) and yy (homozygous recessive) individuals?

Answer 1

The correct answer is explained below:

Explanation:

• The allele for yellow seeds is Y.
• The allele for green seeds is y.
• The yellow colour phenotype is dominant over the green color phenotype.
• The genotype of the parent who is heterozygous is : Yy.
• The gametes produced by the parent who is heterozygous are: Y and y.
• The genotype of the parent who is homozygous recessive is: yy.
• The gamete produced by the parent who is homozygous recessive is: y.
• Crossing the above parents we get the following offspring,

                                           Y                    y

                               y         Yy                  yy

               Phenotype      Yellow          Green

• The genotype and the phenotype of the possible offspring is represent in the Punnett square above.
• The ratio of the genotype is Yy : yy = 1 : 1.
• The ratio of the phenotype is Yellow : Green = 1 : 1.