Which cell junctions form a barrier to the passage of materials?

The correct answer is - tight junctions.

Explanation:

Tight junctions are one of the cell-cell junctions that make a barrier to the passage of material which is a present in epithelia. This barrier is impermeable to most of the materials with soluble molecules. This barrier is made up of the occludin and claudin proteins.

Tight epithelia have tight junctions and examples of such junctions are the distal convoluted tubule or DCT, and the collecting duct of the nephron in the kidney.

Thus, the correct answer is - tight junctions.

explanation:

they can be good for the ecosystem

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.