Final answer:
Endocytosis is the cellular process of taking in substances by engulfing them in a vesicle, while exocytosis is the process of expelling substances by fusing vesicles with the plasma membrane and releasing their contents outside the cell.
Step-by-step explanation:
The correct answer to the question is C) Endocytosis is the process of taking in substances, while exocytosis is the process of expelling substances from a cell. Endocytosis involves the cell membrane engulfing a substance or particle from outside the cell, creating a vesicle that transports the substance into the cytoplasm. There are two main types of endocytosis: phagocytosis and pinocytosis, as well as receptor-mediated endocytosis which is specific for substances recognized by a cell-surface receptor.
On the flip side, exocytosis involves vesicles within the cell transporting material to the plasma membrane. When these vesicles fuse with the plasma membrane, their contents are released into the extracellular matrix. This process is critical for the secretion of substances such as digestive enzymes, hormones, and neurotransmitters.