Where are cell-cell junctions found?

• A. Apical surface
• B. Lateral/Basal surface
• C. Basal surface only
• D. Throughout the entire cell membrane equally

Answer: (B)

Cell-cell junctions form where neighboring epithelial cells meet, so they appear along the lateral membranes that touch each other. The apical surface faces the lumen or outside world and is generally free of such contacts, while the basal surface attaches to the basement membrane and is involved in cell-ECM adhesion rather than cell-cell adhesion. In most epithelia, junctional complexes lie at the apical-lateral border, forming a belt-like region that links neighboring cells and helps create a continuous barrier and coordinated tissue behavior. Because these junctions are confined to contact zones between cells, they are not distributed uniformly across the entire membrane. Thus, the correct location is the lateral surfaces where cells touch each other (often extending toward the basal edge).