Final answer:
Tight junctions regulate paracellular transport by forming a watertight seal between adjacent animal cells, thereby preventing material leakage between them.
Step-by-step explanation:
The type of junction that regulates paracellular transport is the tight junction. Tight junctions form a watertight seal between two adjacent animal cells, preventing materials from leaking through the space between the cells. These junctions are essential for maintaining a selective barrier in epithelial tissues that line organs and cavities. For instance, the tight junctions in the epithelial cells of the urinary bladder are critical to prevent urine from leaking into the extracellular space.