Observe the diagram and answer the following. 

1.  Are these types of guard cells found in monocots or dicots?

2.  Which of these shows a higher water content (i) or (ii)?

3.  Which element plays an important role in the opening and closing of stomata?

(a) The guard cells are bean-shaped which are found in dicot plants.
(b) The guards cells in figure(i) are turgid as, they pull the inner wall of the cell outside thus, they have more water. (ii) cells are flacid, this condition results when cells lose water and close stomatal pore.
(c) The K+ ions when move from neighbouring cells to guarcs cells, lowering their water; potential as a result the water moves inside making them turgid and thus opening stomata.