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.
Complement is activated by antigen-antibody complexes and causes holes to form in the plasma membrane of foreign microbes or cells (lysis). The complement system is considered a nonspecific defense, but it can be activated against specific microbes that have been marked with antibodies.nything that can trigger the immune response is called an antigen. An antigen can be a microbe such as a virus, or even a part of a microbe. Tissues of cells from another person also carry nonself markers and act as antigens.