Question

Which of the following sentences is incorrect with regard to cell junctions?

• A. Cell junctions are points of contact between plasma membranes of adjacent cells
• B. There are 4 types of cell junctions
• C. Cell junctions allow ions to pass from one cell to another
• D. Fluid tight seals cannot be formed by cell junctions

Answer 1

The correct option is D Fluid tight seals cannot be formed by cell junctions

Cell junctions are points of contact between plasma membranes of adjacent cells. There are 4 types of cell junctions - gap junctions, tight junctions, interdigitations and desmosomes. Cell junctions allow ions to pass from one cell to another. Tight junctions are impermeable (sometimes partially permeable) seals that encircle cells and bind them together into leakproof sheets. In other words, the plasma membranes of adjacent cells essentially fuse together tightly in order to limit the leakage of various substances between the two cells.