Final answer:
The middle lamella in plants and tight junctions and desmosomes in animals are important in cell communication and tissue cohesion.
Step-by-step explanation:
The structure and function of the middle lamella in plants and tight junctions and desmosomes in animals serve important roles in cell communication and tissue cohesion. The middle lamella is a layer of pectin that acts as a cementing substance between plant cells, providing structural support and allowing for communication through plasmodesmata. In animals, tight junctions form watertight seals between cells, preventing the movement of substances between cells. Desmosomes, on the other hand, act as spot welds, connecting cells and providing strength to tissues.