Monoclonal antibodies are described as:

• A. Antibodies produced by a single clone of B lymphocytes and produced by the hybridoma method.
• B. A mixture of antibodies generated against multiple epitopes.
• C. Antibodies that recognize carbohydrates only.
• D. Antibodies produced by plants.

Answer: (A)

Monoclonal antibodies are identical antibody molecules produced by a single clone of B lymphocytes, typically via the hybridoma method that fuses a specific B cell with an immortal myeloma cell. Because they come from one clone, all the antibody molecules have the same binding site and recognize the same exact epitope, giving uniform specificity and affinity. This is in contrast to polyclonal antibodies, which are a mixture arising from many B cells and can target multiple epitopes on the same antigen, leading to more variability between preparations. Monoclonals offer reproducible staining in immunohistochemistry and can be used to target a wide range of epitopes, not limited to carbohydrates, and while plants and other systems can be used to produce antibodies, the defining feature here is derivation from a single B cell clone via hybridoma technology.