Answer:
Antibodies are produced by _white cells__ and bind to specific _antigens_ on erythrocytes, causing __agglutination__, or clumping of erythrocytes.
Explanation:
Macrophages are one of the different types of cells that intervene in the organism's defense system against strange substances and pathogen agents. These cells are the principal actors in the immune response.
Macrophages have several functions. They are the principal phagocytes of tissues, capable of recognizing different strange molecules that penetrate the organism, such as bacterias, parasites and, viruses. Macrophages phagocyte these substances and eliminate them, a process known as phagocytosis. When macrophages are activated, they release cytokines that favor inflammation response, which is used to neutralize the pathogen agent. When macrophages phagocyte strange substances, they show the antigens in their surfaces to be recognized by lymphocytes.
Antigens are defined as the strange substances that enter the organism and trigger a series of cellular events that produce defense mechanisms. Antibodies recognize antigens as invaders.
In the organism, there are leucocytes or lymphocytes (white cells) in charge of immune defense. These are B cells, which produce antibodies, and T cells that can destroy infected cells from the body. They all circulate in the blood.
Antibodies are globular proteins produced by lymphocytes in response to the presence of strange molecules. Each type of antibody recognizes and combines with a particular antigen, immobilizing it. After that, the antigen is destroyed by other components of the immune system.
