Bio 212
Lab: Thurs 10:00
Transpiration Laboratory
Abstract:
Transpiration is affected by many things including temperature and humidity; we were interested in seeing what other factors influence the rate that transpiration occurs. The purpose of this experiment was to explore how paint effects transpiration. I hypothesized that the rate of transpiration would decrease with the addition of paint to the bottom or the Laurel twig’s leaves. After collecting and analyzing the data I learned that transpiration rate actually increased with the addition of the paint, the transpiration rate for the control was 2.516 and the transpiration rate for the experiment was 2.904. The relationship between the control and the experiment was significant, meaning the null hypothesis was rejected.
Introduction:
Plants require CO2 to perform functions like photosynthesis. Stomata on the bottom of leaves open and close in order to allow CO2 to diffuse into the plant and O2 to exit them. Transpiration is essential for maintaining the plants water cycle but it is a byproduct of opening and closing the stomata. Transpiration starts in the roots where water uptake occurs, water is then moved up through the plant via the xylem. When the water reaches the leaves evaporation occurs, the water forms a meniscus between the mesophyll cells and the lower pressure potential in this meniscus allows for the evaporation to occur. This evaporation creates a force that pulls water up the plant (Carrier). The stomata control the rate of evaporation and the absorption of CO2.
Transpiration have many factors that can affect how fast transpiration can occur, temperature, humidity, light, and air movement are just a few things that can affect transpiration. Studying transpiration is interesting because we can manipulate factors like these to control the plants water cycle and transpiration. This could be beneficial when trying to move minerals and nutrients up from the roots
Cited: Anderson, Jay (1982): “Factors Controlling Transpiration and Photosynthesis in Taramax Chinensis Lour.” Ecology, Vol. 63, No. 1, February. pp. 48-56 Carrier, Mark (2011): “Lecture 7, Membrane Potential, Transpiration.” University of Oregon. Spring 2012. pp. 2-10.