Which white blood cell type is most associated with phagocytosing bacteria and damaged cells as part of the immune response?

• A. Lymphocyte
• B. Eosinophil
• C. Neutrophil
• D. Basophil

Answer: (C)

Neutrophils are the white blood cells most closely tied to ingesting bacteria and clear-up of damaged cells. They act as the body’s fast-acting first responders to infection, migrating quickly to sites of bacteria and debris where they perform phagocytosis—engulfing the invaders and damaged material. Inside these cells, lysosomes release enzymes and reactive oxygen species to kill what they’ve swallowed, then the neutrophils often die, contributing to pus formation in acute infections. While other white blood cells have important roles—lymphocytes in adaptive immunity, eosinophils in parasite defense and allergy, basophils in promoting inflammation—the direct, efficient phagocytosis of bacteria and damaged cells in the early immune response is a hallmark of neutrophils.