Final answer:
Tight junctions contribute most to the polarization of epithelial cells by separating the cells into distinct apical and basal compartments, thus maintaining the selective barriers of epithelial tissues.
Step-by-step explanation:
The type of junction that contributes the most to the polarization of epithelial cells is the tight junction. Tight junctions are essential for separating the cells into apical and basal compartments, ensuring that there is no extracellular space between them and blocking the movement of substances between the cells. This is fundamental to maintaining the selective barriers that epithelia provide, which is critical for their polarized function.
Tight junctions separate the cells into apical and basal compartments, blocking the movement of substances through the extracellular space between cells. This allows epithelial cells to act as selective barriers.