In specific immunity, what is the role of antibodies?

• A. They produce red blood cells
• B. They become pathogens
• C. They directly destroy pathogens without assistance
• D. They bind to infectious agents and signal white blood cells to destroy them

Answer: (D)

In humoral immunity, antibodies act as tags that identify and alert the immune system to invaders. They are produced by B cells and bind specifically to antigens on pathogens. This binding neutralizes the threat and, crucially, marks the infectious agents for destruction by other immune cells. By binding, antibodies recruit phagocytes (like macrophages and neutrophils) to engulf and destroy the invader and can activate the complement system to help lyse or kill the pathogen. In this way, antibodies signal white blood cells to destroy the infectious agents, rather than acting alone to kill them directly. They do not create red blood cells, do not become pathogens, and their destructive action relies on assistance from other immune components.