When my doctor informed me that my blood type was A+, she cried out the words "royal blood." I felt the strangest sense of pride. In popular belief, A and AB blood type seems to be the dominant blood group of some royalty who feel they have the right to rule through DNA and through blood line. It was a silly feeling that I have to force it down. I don't really know much about blood and what it really meant to have type A+ blood. Most people think about blood types as something medical in nature: that when somebody ends up in a hospital in need of blood, the doctors there would need to make sure they transfused him with a suitable type. Realizing that fact, questions came to mind. Like why do we have different blood types, which of them are compatible, and what do they do? Here's what I learned. What exactly is Blood? According to Dr. Mercola of Mercola.com , blood is a living tissue made up of red blood cells, white blood cells, platelets, and plasma ...