ABO Blood Group

1.   What are the four main phenotypes of the ABO blood group system? The four main phenotypes of the ABO blood group system are A, B, AB, and O.

2.   Which gene locus controls the ABO blood group in humans? The ABO blood group in humans is controlled by a single gene locus located on chromosome 9.

3.   What type of inheritance do ABO blood groups exhibit? ABO blood groups exhibit multiple allelic inheritance with codominance.

4.   Which antigens are present on red blood cells of blood type A? Blood type A has A antigens on the surface of its red blood cells.

5.   Which antibodies are found in the plasma of a person with blood type B? A person with blood type B has anti-A antibodies in their plasma.

6.   Why is blood type O considered a universal donor? Blood type O is considered a universal donor because its red blood cells lack both A and B antigens.

7.   Why is blood type AB considered a universal recipient? Blood type AB is considered a universal recipient because its plasma lacks both anti-A and anti-B antibodies.

8.   What is the biochemical basis of A and B antigens? A and B antigens are glycolipids or glycoproteins that differ in the terminal sugar residue.

9.   What is the genotype of a person with blood type O? A person with blood type O has the homozygous recessive genotype OO.

10.                  What happens if a person with blood type A receives blood from a person with blood type B? If a person with blood type A receives blood from a person with blood type B, a severe transfusion reaction occurs due to pre-existing anti-B antibodies.

11.                  Which allele is recessive in the ABO system? The O allele is recessive to both A and B alleles in the ABO system.

12.                  What is the Bombay phenotype? The Bombay phenotype is a rare blood type where individuals lack the H antigen, so they cannot make A or B antigens even if they have the respective alleles.

13.                  How is the ABO blood group tested in a laboratory? The ABO blood group is tested using a forward grouping method that mixes red blood cells with known antisera.

14.                  Can a father with blood type A and a mother with blood type B have a child with blood type O? Yes, a father with blood type A (genotype AO) and a mother with blood type B (genotype BO) can have a child with blood type O.

15.                  What is the clinical importance of the ABO system in transplantation? The ABO system is clinically important in transplantation because ABO-incompatible transplants often undergo hyperacute rejection.