Marker on the surface of a foreign substance that identifies it to immune cells as "nonself"

Question

Quizplus · Accepted Answer

Antigen is a marker on the surface of a foreign substance that identifies it as "nonself" to the immune cells. Antibodies are proteins produced by B cells in response to an antigen. Bacteria are a type of microorganism that can be targeted by the immune system. Phagocytes are immune cells that engulf and destroy pathogens. Lymphocytes are a type of white blood cell involved in the immune response. Of all the choices, antigen is the best answer for the given definition.

Marker on the Surface of a Foreign Substance That Identifies