The calyx shape for strawberries can be normal and leaf-shaped; in heterozygotes, the calyx has an intermediate shape

The calyx shape for strawberries can be normal and leaf-shaped; in heterozygotes, the calyx has an intermediate shape between normal and leaf-shaped. Determine the possible genotypes and phenotypes of the offspring from crossing two plants with an intermediate calyx shape.

Let us designate the gene that determines the normal shape of the calyx in strawberries as A, then the corresponding gene, which determines the development of the leaf-shaped calyx under conditions of homozygous representation, will be a.

The problem deals with the phenomenon of the so-called incomplete dominance: a combination of genes that cause the development of two different traits within one genotype leads to the phenotypic realization of a new, third trait, intermediate in value.

Strawberries with an intermediate calyx will be Aa.

The parent plants of such strawberries produce sex cells of two types: A and a.

The offspring from crossing such plants will be as follows:

strawberries with a cup of normal shape (AA) – 25%;

strawberries with an intermediate calyx (Aa) – 50%;

strawberries with a leaf-shaped calyx (aa) – 25%.