North Sea: North Sea, shallow, northeastern arm of the Atlantic Ocean, located between the British Isles and the mainland of northwestern Europe and covering an area of 220,000 square miles (570,000 square km).
Your immune system ignores the surface antigens on your own RBCs. However, your plasma contains antibodies, sometimes called agglutinins , that will attack the antigens on foreign RBCs. When these antibodies attack, the foreign cells agglutinate , or clump together; the process is called agglutination . The plasma of a Type A, Type B, or Type O individual always contains either antiâ A or antiâB antibodies, or both, even if the person has never been exposed to RBCs that carry foreign surface antigens. If you have Type A blood, your plasma contains antiâB antibodies, which will attack Type B surface antigens.
The invading microbe or pathogen is called an antigen. It is regarded as a threat by the immune system and is capable of stimulating an immune response. Antigens are proteins that are found on the surface of the pathogen.Antigens are unique to that pathogen.The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium. When an antigen enters the body, the immune system produces antibodies against it. type of white blood cell called a lymphocyte recognizes the antigen as being foreign and produces antibodies that are specific to that antigen. Each antibody has a unique binding site shape which locks onto the specific shape of the antigen.