Which statement is true about gap junctions?

• A. They anchor actin filaments near the apical surface
• B. They form gap channels that allow ions and small molecules to pass between cells.
• C. They seal spaces between epithelial cells
• D. They connect intermediate filaments between cells

Answer: (B)

Gap junctions are specialized intercellular channels that form direct cytoplasmic bridges between neighboring cells. Through these channels, ions and small signaling molecules can pass from one cell to another, enabling rapid electrical and metabolic coupling essential for coordinated tissue function. That’s why describing gap junctions as forming gap channels that allow ions and small molecules to pass between cells is true. For context, anchoring actin filaments near the apical surface is a feature of adherens junctions that link the actin cytoskeleton; sealing spaces between epithelial cells is the role of tight junctions; connecting intermediate filaments between cells is what desmosomes do. Gap junctions are about communication through channels, not anchoring or sealing.