This is the question for the letter I: Immunity!
What is any foreign molecule recognized by the immune system?
A. Antibody
B. Antigen
C. Antioxidant
Scroll down for the answer!
The answer is B: Antigen
The immune system recognizes antigens
Any foreign molecule that enters the body and causes an immune response is an antigen. This could be pollen, bacteria, a virus, a toxin, etc.
Cells called lymphocytes respond to attack the foreign “invader”. One type of lymphocyte, B cells, makes antibodies, which attach to the invader and alert other cells to destroy it.