ABO blood grouping is controlled by gene I which has three alleles and show co- dominance. There are six genotypes. How many phenotypes are possible?

Explanation

Option B is correct. The correct answer is four. The ABO blood grouping system is controlled by the ABO gene, which has three alleles: A, B, and O. The A and B alleles are codominant, which means that both alleles are expressed in the phenotype. The O allele is recessive, which means that it is only expressed in the phenotype if the individual does not have any A or B alleles. The six possible genotypes for the ABO gene are: 1.AA 2.AO 3.BB 4.BO 5.AB 6.OO. The four possible phenotypes for the ABO blood grouping system are: 1.A 2.B 3.AB 4.O The A and B phenotypes are produced by the presence of either two A alleles or two B alleles. The AB phenotype is produced by the presence of one A allele and one B allele. The O phenotype is produced by the presence of two O alleles. Therefore, there are four possible phenotypes for the ABO blood grouping system, despite the fact that there are six possible genotypes