Answer;
-Gap junctions
Explanation;
-Gap junctions are a specialized intercellular connection between a multitude of animal cell-types. they are organized collections of protein channels in cell membranes that allows ions and small molecules to pass between adjacent cells.
-Gap junctions allow the exchange of ions, second messengers, and small metabolites between adjacent cells and are formed by two unrelated protein families, the pannexins and connexins.
Flatworms are unsegmented worms. They have a tail and a head end by don't have any body cavity or specialized respiratory and circulatory organs. They are also bilaterally symmetrical which gives them both upper and lower surface. With this accompanying characteristics they typically have a flat shape or appearance.
