a. Lab Report
Prepared for: Dr. Chuks Ogbonnaya
By: Deborah A. Smith
February 27, 1990
Transpiration is the evaporation of water particles from plant surfaces, especially from the surface openings, or stomates, on leaves. Stomatal transpiration accounts for most of the water loss by a plant, but some direct evaporation also takes place through the surfaces of the epidermal cells of the leaves. The amount of water given off depends somewhat upon how much water the roots of the plant have absorbed. It also depends upon such environmental conditions as sunlight, humidity, winds and temperature. A plant should not be transplanted in full sunshine because it may lose too much water and wilt before the damaged roots can supply enough water. Transpiration occurs as the sun warms the water inside the blade. The warming changes much of the water into water vapor. This gas can then escape through the stomata. Transpiration helps cool the inside of the leaf because the escaping vapor has absorbed heat. Materials and Methods
The 1000 milliliter flask fitted with a three hole rubber stopper, separatory funnel and a measuring pipet. First, fill Erlenmeyer flask with 250 milliliters of distilled water. Put the glass tube with a right angle bend into one hole of the three hole stopper. Place stopper in flask making sure no air bubbles are trapped. Take a plant shoot and cut in the sink under running water. Remove the shoot from water and place the stem through the hole in the stopper and allow one inch of the stem to go into the water in the flask. Place a separate funnel in third hole and fill with water to the upper mark. Coat all joints will sealant and record the position of the meniscus at two minute intervals for 30 minutes. Move the apparatus to the fume hood and measure every two minutes for 30 minutes. Place a plastic bag over the leafy part of...