The antibody is shaped much like the letter Y in the English alphabet. It has two antigen binding sites that are identical in nature. The specificity of these sites is determined by the amino acid sequence that makes it up. Antibodies are complementary to these antigen binding sites, and the antibodies have an incredible ability to recognize a great variety of antigens.
The generally accepted parts of modern cell theory include: All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms
