What is the Difference Between Monogenic and Polygenic Inheritance?

The main difference between monogenic and polygenic inheritance lies in the number of genes involved in determining a particular trait.

Monogenic inheritance refers to the process where a single gene or a single gene pair is responsible for producing a specific trait. In this type of inheritance, the expression of the trait can be predicted according to a phenotypic ratio that follows Mendelian inheritance. Monogenic traits are rare and include characteristics such as cleft chin and face freckles.

Polygenic inheritance, on the other hand, involves the cumulative effects of many genes in determining a trait. This type of inheritance is more complex and does not follow Mendelian inheritance patterns. Polygenic traits are more common and include characteristics like eye color and height.

In summary, the key differences between monogenic and polygenic inheritance are:

Monogenic inheritance is determined by a single gene or gene pair, while polygenic inheritance involves the cumulative effects of multiple genes.
Monogenic inheritance follows Mendelian inheritance patterns, whereas polygenic inheritance does not.
Monogenic traits are rare, while polygenic traits are more common.

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What is the Difference Between Monogenic and Polygenic Inheritance?

Comparative Table: Monogenic vs Polygenic Inheritance

Here is a table comparing Monogenic and Polygenic Inheritance:

Feature	Monogenic Inheritance	Polygenic Inheritance
Number of Genes Involved	Only one gene is involved in determining the character.	Two or more genes are involved in determining a single character.
Trait Examples	Cleft chin, cheek dimples, face freckles, and widow's peaks.	Height, eye color, and hair color.
Inheritance Pattern	Mendelian Inheritance, with discontinuous variations in characters.	Non-Mendelian form of inheritance, with a spectrum of phenotypes.
Phenotypic Ratio	Predictable according to a phenotypic ratio that follows Mendelian inheritance.	The expression of the phenotypic trait does not display complete dominance.
Trait Expression	The presence of monogenic traits is dominant, meaning that even if the offspring is heterozygous for that allele, the trait will still express itself physically.	Polygenic traits display an additive effect of the traits present in the parents.

Monogenic inheritance is a process where a character is determined by a single gene, with two alleles of this gene located in the same locus. Polygenic inheritance, on the other hand, is a deviation of Mendelian Inheritance, where a single character is determined by more than one set of alleles or more than one gene.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.