NEET Class neet Answered

Human skin phenotype is an example of polygenic characteristic which shows continuous variation. Human skin is controlled by six genes each with it's own allele. These alleles control the production of melanin. These genes produces eight different types of gametes and these gametes combine with each other in 64 different ways (genotypes) resulting in a total of seven skin color.

Parents having genotype AABBCC and aabbcc will produce offspring of intermediate colour in the F₁ generation, i.e. AaBbCc genotype. In the F₂ generation of two triple heterozygotes (AaBbCc x AaBbCc) mate, they will give rise to varying phenotypes ranging from very dark to very light in the ratio 1:6:15:20:15:6:1.