and AB+. Austrian physician Archive

Why do we have different blood types?

As a kid when I felt down, my mother used to say “Cheer up kid, after all, you are a B +ve. And I used to think that all the positive people in the world had B+ve blood group and all the pessimists had B –ve. I stuck on to that idea for quite a while before realizing how silly it was. Later in my science classes, I learned the types of the proteins and sugars, inherited from our parents, which determine our blood group. These sugars found (or expressed) on the surface of red blood cells define blood types