Final answer:
Endocytosis is a type of bulk transport where molecules are engulfed by the cell's plasma membrane to form a vesicle and transported into the cell. This active transport process is crucial for large molecules that cannot diffuse or be transported by membrane proteins.
Step-by-step explanation:
A type of bulk transport where molecules move into a cell via vesicles is called endocytosis. This process is a form of vesicle transport and a type of active transport that requires energy. During endocytosis, the plasma membrane of the cell engulfs the substance that needs to be transported into the cell, creating a vesicle around it. The vesicle is then pinched off and transported within the cell. This process is particularly important for the uptake of large molecules that cannot pass through the plasma membrane by simple diffusion or through transport proteins.