The stomata of leaves are surrounded by guard cells. The guard cells help the leaves to regulate the rate of transpiration of water from the leaves by opening and closing the stomata. When water enter the guard cells, they swell and bulge and this makes the stomata to open. So, with high water pressure, the guard cells will stimulate the stomata to open. The reverse will be the case if the water pressure is low.
<span>Na+, cl-, hco3-, and k+ are electrolytes. Na+ is sodium. Cl- is chloride. Hco3- is bicarbonate and k+ is potassium. Electrolytes are needed for our organs and cells to function like they should. We obtain some of these electrolytes through the food we eat, such as sodium from salt and potassium from bananas.</span>
Such direct observational evidence is limited, however, and clouds remain the biggest source of uncertainty--apart from human choices to control greenhouse gases—in predicting how much the climate will change
