Which process involves engulfing of large particles like bacteria by white blood cells?

• A. Pinocytosis
• B. Endocytosis
• C. Phagocytosis
• D. Exocytosis

Answer: (C)

Phagocytosis is the process where a cell, especially certain white blood cells like macrophages and neutrophils, engulfs large particles such as bacteria. The cell extends its membrane around the target with arm-like projections called pseudopods, forming a phagosome that digs into the inside of the cell. This phagosome then fuses with a lysosome to digest the invader. This is distinct from pinocytosis, which takes in fluids and dissolved substances in small vesicles; exocytosis, which exports material from the cell; and endocytosis in general, which covers all forms of bringing material into the cell, with phagocytosis being the specialized form for large particles.