Abstract: The purpose of this experiment is to test different environment effects on plants to see the differences in the rate of transpiration. This experiment was done by placing a plant under a light, one in an aquarium misted with water to express humidity, and another in front of a fan to express wind. The results of this experiment show wind and light increase the rate of transpiration while humidity decreases the rate of transpiration. Introduction: Transpiration is the process in which water is moved through the plant and then removed from through evaporation. Water is taken into a plant through the roots by osmosis. The transportation of water through the plant is due to water potential. Water potential is the potential energy created by the water molecules in the plant stem. Because of water potential, water moves from high concentration to low concentration. The water will then exit through tiny openings on the underside of leaves know as stomata. The stomata allow carbon dioxide and water to move freely into the leaves. The evaporation of water through leaves causes transpirational pull on the water in the xylem, which is why water is continuous up the plant. Bulk flow in plants is the movement of solutes and water through vessels and sieve tubes due to pressure. Bulk flow causes the negative pressure in the xylem causes sap and water to move from the roots to the leaves. Cohesion also aids water movement in plants. Cohesion is the sticking together of water molecules. This makes it easier for water to move throughout the plant since water will move as one large, continuous molecule. Water is cohesive thanks to hydrogen bonds. As water is evaporated through transpiration, the molecule takes its place in the leaf to be evaporated next. There are also different environment factors that can increase or decrease the rate of transpiration. Some of these include wind, light, and humidity. Wind increases the rate of transpiration by helping oxygen enter the leaf. Light also increases the rate of transpiration because the heat helps to increase evaporation. Lastly, humidity decreases the rate of transpiration due to the additional water in the air. This is due to the water potential moving from levels of high to low, and with the additional water in the air, there is no real need for the water to move out.
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