Difference Between Phenotype and Genotype Ratio

The key difference between phenotype and genotype ratio is that the phenotype ratio is the relative number of or the pattern of the offspring manifesting the visible expression of a particular trait while the genotype ratio is the pattern of offspring distribution according to the genetic constitution.

Phenotype and genotype are two terms that use to describe the characteristics of an organism in genetics. These terms help to explain how traits inherit and how they subject to evolution. If consider a particular trait or a characteristic, the phenotype refers to the physical expression or the visible characteristic while the genotype refers to the genetic composition or the set of genes responsible for the characteristic. Both terms immensely contribute to the study of the inheritance of traits. Genotype collectively with the environmental factors influences the phenotype of a trait. In simple words, genes are responsible for the observable expression of a characteristic with a little influence of the environment.  When you perform a cross between two individuals, the resulting progeny population can be analyzed for the phenotype ratio and genotype ratio.

CONTENTS

1. Overview and Key Difference
2. What is Phenotype Ratio
3. What is Genotype Ratio
4. Similarities Between Phenotype and Genotype Ratio
5. Side by Side Comparison – Phenotype vs Genotype Ratio in Tabular Form
6. Summary

What is Phenotype Ratio?

Phenotype is the observable characteristic of an organism. It is the physical expression what is visible to us. What we observe is mainly the collective influence of the genotype and the environmental factors, as the genotype together with the environmental factors determines the visible characteristic.

Genotype or the genetic composition codes the trait of the phenotype. The pattern of the physical expressions of the offspring for a trait is we call phenotypic ratio. Consider the following example d=shown in figure 01. The phenotypic ratio is 9:3:3:1.

What is Genotype Ratio?

Genotype is the genetic makeup of an organism that code for a particular trait or traits. It involves genes that inherit genetic information from parents to offspring. Thus, most of the genes exist as two alleles. Therefore, it can be two dominant alleles, two recessive alleles or a combination of both. As a result of a cross between two genotypes, the offspring generation gets genetic information from their parents. When analyzing the pattern of genetic constitution between the resulted offspring generation, it tells the genotype ratio.

Hence, the following figure nicely explains the genotype ratio.

What are the Similarities Between Phenotype and Genotype Ratio?

• Phenotype and Genotype Ratio are two terms used in genetics.
• They help to study the inheritance of traits and their evolution.
• Also, both are patterns in genetics.
• Furthermore, they are related to each other since genotype influence the phenotype.

What is the Difference Between Phenotype and Genotype Ratio?

The ratio between the offspring population for an observable characteristic is the phenotype ratio. On the other hand, the ratio between the genetic makeup among the offspring population is the genotype ratio. This is the main difference between phenotype and genotype ratio. Therefore, both are useful in genetic studies.

The below infographic presents the difference between phenotype and genotype ratio in tabular form.

Summary – Phenotype vs Genotype Ratio

Phenotype refers to the physical expression while genotype refers to the genetic constitution. After a cross between two individuals, the pattern of expressing a visible characteristic among the offspring population is the phenotype ratio. On the other hand, the pattern of genetic makeup among the offspring population is the genotype ratio. Phenotype ratio differs from the genotype ratio in most cases. However, there are some instances where they are similar. Incomplete dominance and co-dominance are two such occasions. Thus, this is the difference between phenotype and genotype ratio.

Reference:

1.“Genotype–Phenotype Distinction.” Wikipedia, Wikimedia Foundation, 10 July 2018. Available here  

Image Courtesy:

1.”Figure 12 03 02″By CNX OpenStax , (CC BY 4.0) via Commons Wikimedia