Question

Inheritance pattern of ABO blood groups in humans show dominance , co - dominance and multiple allelism. Explain each concept with the help of blood group genotypes.

Answer 1

Dominance can be seen if allele from parent 1 is A or B and allele from parent2 is O in this case since O is recessive, it is unable to express itself and A/B are dominant making the blood group A/B. In case of co-dominance both alleles express themselves. Parent 1 can have allele A and parent 2can have allele B, resulting in the offspring having AB blood group. Multiple allelism is seen because more than 2 alleles determine the genotype. Since, human is a diploid organism it have only 2 alleles on a gene but different alleles (more than 2) determining the genotype of a gene are found when population studies are made.