• # question_answer ABO blood group system is due to A)  Multifactor inheritanceB)  Incomplete dominanceC)  Multiple allelismD)  Epistasis

A gene may have more than two alternative forms occupying the same locus on a chromosome such alleles are known as multiple alleles and the phenomenon is turned as multiple allelism. ABO blood group has 3 alleles. ${{\text{I}}^{\text{O}}}\text{,}\,{{\text{I}}^{\text{A}}}$or $\text{A,}\,{{\text{I}}^{\text{B}}}$or B. Hence, the correct option is [c].