Question

The antigen specificity of a particular B cell:

• A. Is induced by interactions with antigen
• B. Is due to light chains of antibody
• C. Is due to heavy chains of antibody
• D. Is determined by heavy and light chain variable region sequence

Hint:

Variable regions are located at the tips of the arms of the antibody molecule, and they are the antigen-binding sites. These regions contain sequences that are unique and are generated by somatic recombination in the B cells.

Answer 1

The Correct Option is D

Antigen specificity, the ability of a B cell to recognize and bind to a specific antigen, is primarily determined by the variable regions of its antibodies. These regions:
• Form the antigen-binding site, which is highly variable to bind to a wide range of antigens
• Undergo somatic recombination, a process that generates a diverse repertoire of antibody binding sites.
• Involve both the heavy and light chain variable regions, which together form the antigen-binding pocket.
Options A, B and C are incorrect because they do not fully explain how specificity arises. While interaction with antigen is important for activation, it does not determine specificity. The heavy and light chain contribute to specificity and is due to both not just individual chain.