The immune system treats foreign substances such as bacteria and toxins as
A)antigens.
B)antibodies.
C)antitoxins.
D)immunoglobulins.
E)symbionts.

Question

Quizplus · Accepted Answer

The immune system recognizes and responds to foreign substances, such as bacteria and toxins, as antigens. Antigens are substances that are capable of stimulating an immune response and can be recognized by specific antibodies or T cells. Antibodies, antitoxins, and immunoglobulins are all products of the immune response that can recognize and bind to antigens, but they are not how the immune system initially recognizes foreign substances. Symbionts are organisms that live in a mutualistic relationship with their host and are not recognized as foreign by the immune system.

The Immune System Treats Foreign Substances Such as Bacteria and Toxins