1. Particles or macromolecules that are too large and too charged or polar to pass through biological membranes are taken into cells by a process called endocytosis. Phagocytosis is one of three types of endocytosis. 2. In phagocytosis, which means "cellular eating," part of the plasma membrane engulfs the particle. Unicellular protists use phagocytosis for feeding, and some white blood cells use it for defending the body, engulfing foreign cells or substances. The resulting vesicle, called a ph