Fill in the blanks:
1) The blood groups are classified on the basis of presence or absence of _____________ on the surface of RBC.
2) _______ is the most important blood group system in human blood transfusion.
3) The ________system is the second most significant blood-group system in human-blood transfusion.
4.) ______ is the most important antigen after A and B antigens.
5). After a ____________ transplant, the recipients blood type eventually changes to the donor type.
6.) Individuals with type _________ blood are often called universal donors, and those with type _________ blood are called universal recipients.