Question

Which among the following shows a different type of underlying genetic inheritance than the rest?

• A. The skin colour of human beings
• B. The height of human beings
• C. Kernel colour of wheat
• D. ABO blood type in human beings

Answer 1

The correct option is D ABO blood type in human beings

The skin colour of humans, their height and the kernel colour of wheat are examples of inheritance pattern wherein these phenotypic characters are controlled by polygenes. Such a type of inheritance is called polygenic inheritance. Here, action of several genes control and regulate of these characters. Different genes at different loci of the DNA puts a cumulative effect and express varying types of a phenotype among individuals. But the different blood types in human beings are controlled by different alleles of a gene. The human ABO blood group is controlled by the gene I, which has three alternative forms/alleles $I^A,I^B$and i. The occurrence of different blood types in human beings is due to these multiple alleles.