What is phagocytosis?

Phagocytosis is defined as the process by which cells engulf large particles or microorganisms. This is a critical function of certain immune cells, such as macrophages and neutrophils, which use phagocytosis to identify and eliminate pathogens or dead cells from the body. During phagocytosis, the cell membrane extends around the particle, eventually engulfing it and forming a vesicle within the cell. This vesicle then fuses with lysosomes, where the ingested material is broken down and digested.

The other options describe different biological processes that are not related to the ingestion of large particles. For example, the process of 'drinking' liquids refers to pinocytosis, which is a form of endocytosis involving the uptake of fluids and small molecules, rather than larger particles. Cell division for growth pertains to mitosis or meiosis, which are processes of cellular reproduction and growth, and the transportation of nutrients is typically associated with various forms of transport mechanisms in cells that do not involve engulfing particles. Thus, the correct choice accurately captures the essence of phagocytosis as a specific form of cellular 'eating.'