What is phagocytosis?

• A. The process of forming new blood vessels
• B. The process by which a cell engulfs and digests pathogens
• C. The process of releasing cytokines
• D. The process of producing antibodies

Answer: (B)

Phagocytosis is defined as the process by which a cell, typically a type of white blood cell known as a phagocyte, engulfs and digests pathogens or other foreign particles. This mechanism plays a crucial role in the immune response, allowing the body to eliminate harmful microorganisms, debris, and dead cells. During phagocytosis, the cell membrane extends around the pathogen, creating a vesicle known as a phagosome, which then merges with lysosomes to degrade the engulfed material through the action of enzymes.

The other options describe different biological processes that are part of the immune system or related functions, but they do not accurately represent phagocytosis. For instance, forming new blood vessels pertains to angiogenesis, while releasing cytokines involves signaling processes crucial for immune communication. Producing antibodies relates to the humoral immune response, where B cells create specific proteins to neutralize pathogens. Each of these processes is vital to immune function, but they do not encompass the specific action of phagocytosis itself.