Final answer:
Phagocytosis is the process by which a cell engulfs and destroys large particles, such as microorganisms, through a type of white blood cell known as a neutrophil.
Step-by-step explanation:
The act of white blood cells engulfing a bacterium is known as phagocytosis. Phagocytosis is a crucial defense mechanism employed by certain white blood cells, particularly neutrophils and macrophages, to eliminate foreign particles, such as bacteria and other microorganisms.
During phagocytosis, the white blood cell surrounds the bacterium with its cell membrane, forming a vesicle called a phagosome. Subsequently, lysosomes, which contain digestive enzymes, fuse with the phagosome to create a phagolysosome. The enzymes within the phagolysosome break down the engulfed bacterium, rendering it harmless.
Phagocytosis is a fundamental aspect of the innate immune response, serving as a primary line of defense against infections. It plays a crucial role in maintaining the body's overall health and protecting against a variety of pathogens.