Final answer:
The process when an amoeba surrounds and ingests a particle of food is called Phagocytosis. It involves the extension of pseudopodia to engulf the particle and the subsequent digestion within a phagosome that fuses with a lysosome.
Step-by-step explanation:
What is it called when a blob-like one-celled amoeba surrounds a particle of food? The correct answer is A) Phagocytosis. This term refers to the process by which cells, such as amoeba, engulf large particles or even other cells. In the case of amoebae, they extend pseudopodia to envelop the food particle, eventually enclosing it in a structure known as a phagosome.
This vesicle then fuses with a lysosome, where hydrolytic enzymes break down the ingested material. The remaining undigested waste is later expelled from the cell through a process called exocytosis. Phagocytosis is a type of endocytosis, which is a broad category including also pinocytosis and receptor-mediated endocytosis.