Final answer:
Pinocytosis, or "cell drinking", is a biological process where a cell takes in water and other molecules from the extracellular fluid. It is a variation of endocytosis and does not require the merging of vesicles with a lysosome. Pinocytosis is a non-specific process that helps the cell to absorb fluids and dissolved substances.
Step-by-step explanation:
Pinocytosis, also known as "cell drinking", is a process in which a cell takes in molecules, including water, from the extracellular fluid. This process is a variation of endocytosis and results in the formation of small vesicles that do not need to merge with a lysosome. Pinocytosis is a non-specific process that enables the cell to take in fluids and dissolved substances.