Question

Inheriatance of skin colour in human is an example of

• A. Codominance
• B. Point mutation
• C. Chromosomal aberration
• D. Polygenic inheritance

Answer 1

The Correct Option is D

The question asks about the type of inheritance that skin colour in humans exemplifies. Let's go through the options:

1. Codominance: Codominance occurs when both alleles in a gene pair in a heterozygote are fully expressed, resulting in offspring with a phenotype that is neither dominant nor recessive. An example of codominance is the AB blood type, where both A and B alleles are expressed equally. This is not the case with skin colour.
2. Point mutation: A point mutation refers to a single nucleotide base change, insertion, or deletion in a DNA sequence. It generally leads to a change in a single gene rather than altering complex traits like skin colour.
3. Chromosomal aberration: Chromosomal aberrations are changes in the structure or number of entire chromosomes. While they can lead to significant phenotypic effects, they do not explain the continuous variation typically seen with traits like human skin colour.
4. Polygenic inheritance: Polygenic inheritance is a form where multiple genes (called polygenes) influence a single trait. Each of these genes may have additive effects on the phenotype. In humans, skin colour is determined by multiple genes, each contributing to the pigment quantity in the skin, leading to a wide range of possible skin tones. Therefore, human skin colour is an example of polygenic inheritance.

The correct answer is Polygenic inheritance, as it involves multiple genes contributing to a single trait, fitting the continuous variation seen in human skin tones.