Question

Choose the correct option with respect to the genetic makeup of the ABO blood grouping system in humans.

• A. 4 Alleles, 4 phenotype and 6 genotype
• B. 3 Alleles, 6 phenotype and 4 genotypes
• C. 4 Alleles, 6 phenotype and 4 genotypes
• D. 3 Alleles, 4 phenotypes and 6 genotypes

Answer 1

Answer: (D)

ABO blood group system is example of multiple allelism in which 3 alleles are there to control the blood group. These 3 alleles are A (Dominant), $B$ (Dominant) and O (Recessive). This blood grouping has 4 types of phenotypes (as 4 blood groups) which are $A,B,O$ and $AB$ . This grouping has total 6 types of genotypes which are $AA,AO,BB,BO,AB$ and $OO$ .