Alyssa MinnellaDr. IobstAP Biology27 November 2017Transpiration LabPurpose- The purpose of this lab was to observe and test how different environmental factors affect the rate of transpiration in plants.Background-Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. More simply transpiration is the evaporation of water from plants. It occurs at the leaves while their stomata are open for the passage of CO2 and O2 during photosynthesis. It is responsible for pulling water up from the roots to provide the leaves with minerals and nutrients and to cool the leaves down. Transpiration rates vary widely depending on weather conditions.The rate of this process could be affected by light, temperature, humidity, and wind. Plants transpire more rapidly in the light than in the dark. This is mostly because light stimulates the opening of the stomata. Light also speeds up transpiration by warming the leaf. Plants transpire more rapidly at higher temperatures because water evaporates more rapidly as the temperature rises. The rate of diffusion of any substance increases as the difference in concentration of the substances in the two regions increases, so when the surrounding air is dry, diffusion of water out of the leaf goes on more rapidly. When there is no breeze, the air surrounding a leaf becomes increasingly humid
Procedure-Whole Plant:1.Remove a plant from its container and place it into a plastic bag. Tie a string firmly around the bag at the base of the plant, and make sure there is no air in the bag. Remove any flowers from the plant. 2.Weigh the plant and record it.