Which of the following best describes what an antigen is?
A)a molecule,such as a polypeptide or carbohydrate,that initiates a response from the immune system
B)a protein in the immune system that is used to identify potential pathogens
C)a molecule that is used during an immune response to enhance the binding of antibodies to damaged cells
D)all of the above

Question

Quizplus · Accepted Answer

An antigen is a molecule, such as a polypeptide or carbohydrate, that initiates a response from the immune system. This can include triggering the production of antibodies or the activation of immune cells.

Answer: D 
 All of the answer choices are partially correct, but only choice A fully describes what an antigen is. While there are proteins in the immune system used to identify potential pathogens (choice B), antigens themselves do not have this function. Additionally, while there are molecules used during an immune response to enhance antibody binding (choice C), these are not specifically referred to as antigens.

Which of the Following Best Describes What an Antigen Is