Antibodies that bind to the same epitope are of the same

• A. Allotype
• B. Autotype
• C. Idiotype
• D. Isotype

Answer: (C)

The binding site of an antibody is shaped by its variable regions, which determine exactly which epitope the antibody can recognize. This set of determinants is called the idiotype. If two antibodies bind the same epitope, their paratopes are compatible with that epitope, reflecting a shared idiotype in how their variable regions are configured to recognize that specific site.

Isotype refers to the antibody class (such as IgG, IgA) and relates to constant regions and effector functions, not which epitope is bound. Allotype are genetic variations in the constant regions between individuals, not about epitope binding. Autotype isn’t a standard term used for this concept.