A single-celled organism is able to engulf large solid particles from its environment. The organism relies on the process of

Phagocytosis is a type of endocytosis in which a cell surrounds and engulfs large solid particles, bringing them inside in a vesicle. Pinocytosis takes in droplets of fluid, while osmosis and facilitated diffusion move substances across a membrane without engulfing solid particles. Therefore, the correct choice is phagocytosis.

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