AP Lab #11 Plant Transpiration August 18, 2014 PURPOSE: What factors, including environmental factors, affect the rate of transpiration? Background: Transpiration is the evaporation of water fom plants. It mostly occurs at the leaves through the stomata. It also pulls up water from the roots to supply photosynthesis, bring minerals up from the roots, and to cool the leaf. Hypothesis: If the plant is placed in front of a fan, then the rate of transpiration will increase If the plant is placed in light, then the rate of transpiration will increase. If the plant is placed in a moist area, then the rate of transpiration will decrease. If the plant is placed in the dark, then the rate of transpiration will decrease. MATERIALS & PROCEDURE: