What type of endocytosis involves a cell engulfing large particles or whole cells?

Phagocytosis is the type of endocytosis that involves a cell engulfing large particles or even whole cells. This process is essential for the immune system, as certain cells, like macrophages, utilize phagocytosis to remove pathogens, dead cells, and other debris. During phagocytosis, the cell membrane extends around the particle, creating a pocket that eventually encloses the particle in a vesicle, which is then brought into the cell for processing or destruction.

In contrast, pinocytosis refers to the ingestion of liquid and small solute particles, and is often described as "cell drinking." Exocytosis, on the other hand, is the process by which cells expel materials, and it does not involve engulfing substances. Anabolic pathways refer to metabolic processes that build molecules from smaller units, which is unrelated to the engulfing of particles. Understanding the specific functions and processes associated with each term clarifies why phagocytosis is the correct answer for the engulfing of large particles or whole cells.