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.
Earth’a temperature was too high for solid rock to form.
Answer;
Endosymbiotic theory is important as it explains the origin of the chroloplast and mitochondria. It also explains the formation of the eukaryotic cells.
Explanation;
Endosymbiotic theory explains the origins of eukaryotic cell organelles such as mitochondria in animals and fungi and chloroplasts in plants.
Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria, specifically alpha-proteobacteria and cyanobacteria, respectively.