Question

Write a short note on Blood group

Answer 1

On the surface of blood cells, there are more than
Thirty antigens that induce various blood groups. Two types of blood grouping systems are widely used in the world. According to the first system type of blood group is determined by gene$I$ (isoagglutinin). The second blood grouping system type of blood groups is determined by rhesus antigen, a protein present in the surface of red blood cells of many peoples.

Complete answer:
Two types of blood grouping system
$ABO$ system
-Karl Landsteiner was the first to report on human blood groups according to the$ABO$system.
The $ABO$ blood group is determined by gene $I$ (isoagglutinin). This gene has three alleles: ${I_A}$, ${I_B}$
and ${I_O}$ The proteins produced by the${I_A}$and${I_B}$
alleles are called antigen $A$ and antigen $B$.

Blood groups	Genotype	Antigens present in the surface of RBC	Antibodies Present in plasma
$A$	{I_A}{I_A} \\\ {I_A}{I_O} \\\	$A$	$B$
$B$	{I_B}{I_B} \\\ {I_B}{I_O} \\\	$B$	$A$
A$$$$B	${I_A}{I_B}$	A$$$$B	None
$O$	${I_O}{I_O}$	None	$A$,$B$

Transfusions, multiple blood groups, i.e. $ABO$ blood groups, beneficiaries and donors must cooperate with each other. Otherwise, the recipient's immune system produces antibodies that cause the transfused cells to clump together and block blood flow through the capillaries.
Note: Blood groups $A$, $B$ and $O$ were discovered by Landsteiner, and blood group A$$$$B was discovered by de Costello and Steini.
$O$ is the most important blood type for transfusion. Therefore, people with A$$$$B blood are called universal beneficiaries, and people with $O$ blood are called universal donors. In blood transfusion between incompatible donors and recipients, when the antigen reacts to cells and antibodies in the plasma, blood clots form that block the capillaries.