Question

Who discovered the blood groups of man?
A. Edward Jenner
B. Larven
C. Karl Landsteiner
D. William Harvey

Answer 1

Hint: The ABO blood group system is used to denote the presence of one, both, or neither of the A and B antigens on erythrocytes. The associated anti-A and anti-B antibodies are usually IgM antibodies, produced in the first years of life by sensitization to environmental substances such as food, bacteria, and viruses.

Step by step answer:The ABO blood types were first discovered by an Austrian Physician Karl Landsteiner working at the Pathological-Anatomical Institute of the University of Vienna. In 1900, he found that red blood cells would clump together (agglutinate) when mixed in test tubes with sera from different individuals and that some human blood also agglutinated with animal blood.
He stated that “ The serum of healthy human beings not only agglutinates animal red cells but also often those of human origin, from other individuals. It remains to be seen whether this appearance is related to inborn differences between individuals or it is the result of some damage of bacterial kind”.
In 1901, he made a definitive observation that the blood serum of an individual would agglutinate with only those of certain individuals. Based on this he classified human blood into three groups, namely group A, group B, and Group C. He defined that group A blood agglutinates with group B, but never with its type. Similarly, group B blood agglutinates with group A. Group C blood is different in that it agglutinates with both A and B. This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930.

Hence, the correct option is (C) Karl Landsteiner

Note: Karl Landsteiner referred to the specific blood group interactions as isoagglutination, and also introduced the concept of agglutinins (antibodies), which is the actual basis of antigen-antibody reaction in the ABO system. Thus, he discovered two antigens (agglutinogens A and B) and two antibodies (agglutinins - anti-A and anti-B). His third group C indicated the absence of both A and B antigens, but contains anti-A and anti-B.