Which statement best describes the primary function of antibodies in humoral immunity?

Which statement best describes the primary function of antibodies in humoral immunity?

• A. Antibodies directly kill infected cells.
• B. Identify and neutralize pathogens, facilitate phagocytosis.
• C. Produce cytokines only.
• D. Inhibit clotting factors.

Answer: (B)

In humoral immunity, antibodies act as soluble tags that recognize antigens on pathogens or toxins, neutralizing them and marking them for destruction. They can block a pathogen or toxin from entering cells, coat invaders to make them easier for phagocytes to ingest (opsonization), and activate the complement system to enhance clearance. They don’t directly kill infected cells or produce cytokines themselves, and they aren’t involved in inhibiting clotting factors. This combination—identification, neutralization, and promotion of phagocytosis—best describes their primary function.

In humoral immunity, antibodies act as soluble tags that recognize antigens on pathogens or toxins, neutralizing them and marking them for destruction. They can block a pathogen or toxin from entering cells, coat invaders to make them easier for phagocytes to ingest (opsonization), and activate the complement system to enhance clearance. They don’t directly kill infected cells or produce cytokines themselves, and they aren’t involved in inhibiting clotting factors. This combination—identification, neutralization, and promotion of phagocytosis—best describes their primary function.