The blood grouping system plays quite an important role in blood transfusion.
Our immune system is capable of recognizing another blood type as foreign material and attacks it if introduced into the body causing a transfusion reaction.
A negative blood group is said to be rarest and is capable of donating whole blood as well as red blood cells.
In comparison to all the other eight blood types, the ratio of the distribution of negative blood types is about 8%, whereas that of AB negative ratio of distribution is about 1%.