yes... and on that very microscopic level, there are three main antigens - A, B and D.
People with A antigens only on their red blood cells are group A, only B antigens are group B, both A and B are AB and neither A or B are group O.
Next most important is the D antigen - you either have it (rheseus D positive) or you don't (rhesus negative). Also there are a multitude of more minor antigens such as Duffy and Kell. Hop this answers your question!
Blood grouping involves antibodies in the serum as well as antigens on the red cells.Group A people have anti-B, group B people have anti-B, group O peple have both and group AB people have none.This is why its important that people receive the correct group if they are having a transfusion.Give group B blood to a group A patient and the patient's anti-B will react against the donor blood potentially killing the patient.
I don't think you're born with the antibodies, BUNNY ,though I'm open to correction on this one... If you are challenged with the wrong blood type, you'll develop antibodies, so it's subsequent wrong transfusions that matter...hence the problem with second Rh +ve pregnancies in a Rh -ve woman.
Medico, you're not born with the antibodies but I think any initial blood transfusion with the incorrect blood type is harmful. The reason that rh- women may attack their rh+ babies during a second pregnancy is that only a minute quantity of the blood cells from the initial pregnancy pass onto the mother, not a significant amount for the mother to attack the babies bllod but this small amount may multiply during a second pregnancy, rather in the same manner that a vaccine works.
Medico you should check your facts!The anti-A and anti-B are unusual and important antibodies as they are the only ones that you are born with. This is why correct blood typing is so imporatnt. There are many other antibodies that you can form if you are exposed to a foreign antigen via blood transfusion or pregnancy, but your Anti-A/Anti-B are naturally occuring.