Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: In endocytosis, a substance or particle from outside the cell is engulfed by the cell membrane. The membrane folds over the substance and it becomes completely enclosed by the membrane. There are two main kinds of endocytosis: pinocytosis and phagocytosis. Answer: endocytosis
What is the term for a particle from outside the cell engulfing the cells membrane?