Question

Dihybrid Practice Problems

Answer 1

Answer:

a. Genotype of the parents are; Rr and rr

b. Please find the explanation to A below

Explanation:

This question involves a single gene that codes for flower color in a plant. The allele for red flower (R) is dominant over the allele for white flower (r). This means that a plant that is heterozygous for flower color (Rr) will be red.

In a cross between a plant with red flowers and white flowers, the phenotype of the offsprings is represented as: 37 plants with red flowers and 41 plants with white flowers. Observing from this number, one would realize that the phenotype ratio is equivalent to 1:1. This phenotypic ratio is only possible when the parent with red flower is heterozygous for the gene i.e. Rr. Hence, the genotype of the parents are: Rr and rr.

b) If one were to cross Rr (red flower) × rr (white flower), the phenotypic ratio of red to white offsprings will be 1:1. Hence, judging from the ratio got from the cross of the two parents above (1:1), the parental genotypes are Rr and rr.