Question

In four-o'clock plants, red flower color is dominant to white flower color. However, heterozygous plants have a pink color. If pink-flowered plants are self-crossed, what will be the phenotypic ratios of their offspring?

A. ½ pink, ½ white
B. All pink
C. ½ red, ½ pink
D. ¼ red, ½ pink, ¼ white
E. 1/3 red, 1/3 pink, 1/3 white

Answer 1

Answer:D. ¼ red, ½ pink, ¼ white

Explanation: Phenotypic ratio is the expression of the genetic makeup of an individual.

4'o clock plant is a plant that exhibit codominance.

Codominance is a condition in which the two allele of a gene are contributing to the phenotype of an individual. In 4'o clock plant both allele A=( red color)and a=(white color) are both contributing to the phenotype hence the color pink.

The gentopyic ratio is AA,Aa Aa, aa

The phenotyic is ¼ red, ½ pink, ¼ white.

Aa(Heterozygous) having the two allele interract gives pink color.