Good day everyone out there. Today I will be discussing briefly what makes a particular 'human blood' different from another. What i want to discuss is called ABO blood group system out of over 400 blood group system known. It is one of the two most immunologically important blood group system (the other being Rhesus blood group system).
You probably have learnt that you are of a particular blood group vis-à-vis A+, B+, AB+ O+, A-, B-, AB- and O-.
Before I delve into that, there is something called H gene. The inheritance of it at conception changes a precursor substance present on the red cells to H substance through a transferase enzyme.
Individuals with A blood group has an A gene which produce a transferase enzyme (1,3 N-acetylgalactosaminyl transferase) that convert the H substance into A antigen which is present on the red cell.
Individuals with B blood group has B gene which produce a transferase enzyme (1,3 galactosyl transferase) that convert the H substance into B antigen which is present on the red cell.
Individuals with AB blood group has both A and B genes and thus employ both transferase enzymes mentioned above to convert the H substance into A and B antigen which is present on the red cells.
Individuals with O blood group have an inactive transferase enzyme so that the H antigen remain unchanged on the red cells.
Whether you are Positive or Negative (as in A Positive; A+ etc ) is another blood group classification on its own called Rhesus blood grouping system. It has nothing to do with what I discussed earlier.

SUMMARY: Distinguishing feature that makes one blood group different from another one is as a result of the presence or absence of these so called Antigens on your red cells.
It should be noted that no blood group is superior to another. Everyone is unique on its own. After all, variety is the spice of life.
Thank you for your time.

Some people have blood group F9

Nice attempt at keeping things simple for the non-science fellas....

Nice write-up OP... But you could have included some information on possible blood donations among the blood groups of the ABO system. A lot of people still don't know such basics.

Well shaa... You try coz there's so much to discuss about the ABO and Rhesus systems.

Once again, nice write-up... Its simplicity is quite good for the general audience.

Thank you op for this piece