Final answer:
Phagocytosis is the process in which white blood cells like neutrophils and macrophages engulf and destroy invading pathogens as part of the immune response.
Step-by-step explanation:
The process in which certain white blood cells ingest invaders is known as phagocytosis. This is an essential part of the immune response, where cells like neutrophils and macrophages engulf and destroy invading pathogens. During phagocytosis, a white blood cell extends portions of its membrane around the target particle, forming a phagosome that engulfs the particle. This phagosome then fuses with a lysosome, allowing the hydrolytic enzymes within to digest the invader, effectively neutralizing the threat.
Some bacteria have developed mechanisms to evade this process, either by escaping from the phagosome before it fuses with the lysosome or by preventing the fusion altogether. However, for most pathogens, phagocytosis followed by lysosomal digestion results in destruction of the foreign material.