Q. ABO blood groups in human are controlled by the gene I. It has three alleles $- I^{A}\ ,\ I^{B}$ and i. since there are three different alleles, six different genotypes are possible. How many phenotypes can occur?
A) Three
B) One
C) Four
D) Two
Explanation
In ABO blood group system, inheritance of grouping is controlled by a single autosomal gene on chromosomal-9 with three major alleles A, B, an O ൫I , I and I ൯. The ABO blood group system has at least 6 alleles. On the basis of presence or absence of antigens and antibodies four blood groups (phenotypes) have been differentiated-A, B, AB and O blood groups. The phenotype, genotype, antigen and antibody of blood group ABO. Phen otype Genotyp e Antige n Antibo dy A I ୟ I ୭ , I ୟ I ୟ A b B I ୠ I ୭ , I ୠ I ୠ B a AB I ୟ I ୠ A, B None O I ୭ I ୭ None a, b
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.