Question

Polygenic Trait means

• A. Several genes influence different traits; genes for a polygenic trait may be scattered along the same chromosome
• B. Several genes influence a trait; genes for a polygenic trait are not scattered along the same chromosome or different chromosomes
• C. Several genes influence different traits; genes for a polygenic trait are not scattered along the same chromosome or on different chromosomes
• D. Several genes influence a trait; genes for a polygenic trait may be scattered along the same chromosome or located on different chromosomes

Hint:

• Polygenic Inheritance A single phenotypic trait is controlled by the additive effects of two or more genes.
• Examples: Human height, skin color, intelligence, crop yield.
• These traits often exhibit continuous variation.
• The contributing genes (polygenes) can be on the same or different chromosomes.
• Contrast with Pleiotropy}, where one gene influences multiple traits.

Answer 1

The Correct Option is D

A polygenic trait refers to a trait that is influenced by multiple genes. These genes can be located either on the same chromosome or spread across different chromosomes. Each gene may contribute to the trait in varying degrees, and the cumulative effect of these genes results in the phenotype observed.

For example, human height is a polygenic trait as it is determined by the combination of many genes rather than a single gene. This means that slight changes in any of these genes may affect the overall expression of the trait. In essence, polygenic traits are characterized by continuous variation in phenotypes, unlike traits controlled by a single gene which typically show discrete variation.

Characteristics	Polygenic Trait
Number of Genes Involved	Several
Chromosomal Location	May be scattered along the same chromosome or on different chromosomes
Trait Variation	Continuous (e.g., height, skin color)

The correct understanding regarding polygenic traits is that several genes influence a trait; genes for a polygenic trait may be scattered along the same chromosome or located on different chromosomes.