In immunology, what term describes a substance, often found on the surface of a pathogen, that triggers a specific response from the immune system?

Explanation

An antigen is a substance, frequently a protein found on the surface of a pathogen like a bacterium or virus, that the immune system recognizes as foreign and responds to by producing specific antibodies designed to target that particular antigen. This antigen-antibody relationship is central to how the immune system identifies and defends against a wide range of different pathogens. Vaccines typically work by introducing a specific antigen, or something that closely resembles it, to safely stimulate this immune response in advance of a real infection. Explore more Everyday Science MCQs on mcqstutor to keep practicing.