Question

Which pair of features represents polygenic inheritance?

• A. Human eye colour and sickle cell anaemia
• B. Hair pigment of mouse and tongue rolling in humans
• C. ABO blood groups in humans and flower colour of Mirabilis jalapa
• D. Human height and skin colour

Answer 1

Answer: (D)

A polygenic trait is the one that is governed by more than one gene. Human skin colour is a polygenic trait governed by more than one gene where dominant allele of each gene express only a part of trait and the full trait is expressed only in the presence of dominant alleles of all multiple genes, is called polygenic inheritance. These genes control skin pigmentation only, no other phenotypic trait is affected by these genes. Likewise, human eye colour and hair pigment in the mouse are polygenic but tongue rolling in humans is not polygenic.
Human blood group inheritance is the example of codominance and multiple alleles. It is governed by three alleles namely $I^A$, $I^B$ and i. Flower color in Mirabilis jalapa is governed by two alleles of a gene that show incomplete dominance.
Sickle cell anaemia is governed by two alleles of a gene $H{b}^b$ and $H{b}^s$.
Therefore, the correct answer is option D.