Assertion : Gap junctions perform cementing function to keep the neighbouring cells together. Reason : Tight junctions facilitate the cells to communicate with each other by connecting the cytoplasm of adjoining cells, for rapid transfer of ions, small and big molecules, etc.

Step-by-step solution

Gap junctions are direct cytoplasm to cytoplasm connections between many kinds of animal cells, these are meant for chemical exchange between cells. Whereas tight junctions are the regions where membranes of adjacent animal cells are held close together by sealing strands. They lie cells firmly and check movement of materials between them.