Chapter 9, Problem 1LTB

Is a round yellow pea seed (genotype Rr Y y) an example of polygenic inheritance? Why or why not?

Summary Introduction

To write:

Whether a yellow colored pea with round shape is an example of polygenic inheritance.

Introduction:

The inheritance in which a polygenic trait is inherited by an organism is called polygenic inheritance. The polygenic trait is a type of trait in which two or more genes control a particular trait. The polygenic traits are different from normal traits as they have multiple genes controlling a particular trait.

Explanation of Solution

The round pea seed with yellow color (genotype RrYy) contains two genes for color and shape. One gene codes for the color and the other codes for the shape. There is no gene that codes for both shape as well as the color. The genes separate during cell division. This is called independent assortment. The gene coding for color separates from the gene coding by the process of independent assortment. This indicates that a pea plant with genotype “RrYy” is not an example of polygenic inheritance.

Conclusion

Therefore, a yellow and round pea seed with genotype “RrYy” is not an example of a polygenic trait. This is because both traits are controlled by different genes and not by a single gene.