NEET BIOLOGY

GENETICS AND EVOLUTION

GENETIC BASIS OF INHERITANCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Trait determined by more than one gene, sometimes hundreds of genes.
A
polygenic
B
multiple alleles
C
codominant
D
sex linked
Explanation: 

Detailed explanation-1: -A polygenic trait is a characteristic, such as height or skin color, that is influenced by two or more genes. Because multiple genes are involved, polygenic traits do not follow the patterns of Mendelian inheritance . Many polygenic traits are also influenced by the environment and are called multifactorial.

Detailed explanation-2: -In polygenic inheritance, traits are determined by multiple genes, or polygenes. Polygenic traits may express several different phenotypes, or displayed characteristics. Polygenic inheritance is a type of incomplete dominance inheritance, where the expressed phenotypes are a mixture of inherited traits.

Detailed explanation-3: -In humans, height, skin color, hair color, and eye color are examples of polygenic traits. Type-2 diabetes, coronary heart disease, cancer, and arthritis are also deemed polygenic. However, these conditions are not just genetic since polygenes can be influenced by environmental factors.

Detailed explanation-4: -Polygenic inheritance refers to the inheritance of a trait governed by more than one genes. Generally, three or more genes govern the inheritance of polygenic traits.

Detailed explanation-5: -In polygenic inheritance, a particular trait is controlled by 3 different genes. The given problem is of polygenic inheritance. In this, phenotypic ratio is 1:6:15:20:15:6:1 instead of 27:9:9:9:3:3:3:1 in F2 generation. In the given example, the genotype of parents is AaBbCc and AaBbCc.

There is 1 question to complete.