The student thought that with an increase in temperature would come an increase in water loss through transpiration. Once I have obtained my results I will plot them on a graph. Phenyl mercuric acetate solution 10 2 M Stock solution 3. Each stomata has a slit like opening called the stomatal pore, which is surrounded by two special cells called the guard cells. It checks the evaporation of water.
Plant C was placed on the windowsill so it could be exposed to natural sunlight for the duration of the day. Completing this lab and creating this lab report gave me a higher understanding of biological processes and general processes of scientific labs. Fluorescent striplights would be suitable. LabBench Activity Design of the Experiment The Potometer A potometer is a device that measures the rate at which a plant draws up water. Try to get a length of stem about 8 cm long with several leaves at the top. Whether we jog up the stairs, are stuck in a crowded elevator, or just have too many layers of clothing on, we release water in an effort to keep our body temperature relatively constant.
Did different plants lose different amounts of weight, or did they lose around the same amount? This transpirational water loss is a necessary evil for plant life. If the water is not replenished the plant wilts and dies but if it is the plant constantly transpires to live. Record the vernier scale reading in the following ways before final computation: First coincide the zero of the measuring wheel with zero of the vernier scale. Observation The time taken to change colour of the cobalt chloride paper from blue to pink on the lower leaf surface is less than the upper surface. The pointer points to a stoma. Materials and Equipments Required : 1.
This is important to classroom study because it reinforces the idea that many factors effect transpiration rate and this lab helps investigate which environments make the process happen faster. . The room condition was used as a constant and remained to be in the middle in terms of transpiration and mass lost of all the different conditions. Record the time in sec for a standard colour change of the cobalt chloride papers in both the cases the paper turns pink when it absorbs water vapour moisture. The relationship between the two processes mentioned above can be determined by two experimental procedures: a Direct determination with the help of glass apparatus.
Wind moves the air and water vapour away from the leaf, this increases the water potential gradient from the plant to the air. It had the greatest weight loss which shows that it had the greatest amount of water loss. Phenyl mercuric acetate is one of the potent antitranspirant chemicals that causes the partial closure of stomatal pores and, thereby, regulates the transpiration process. Also, for the light condition, the heat baths were not refilled every day, which could have lead to the heat also affecting the results and caused transpiration to happen at a faster rate. The dependent variable in this experiment is the mass lost through transpiration for each variable. Apply the blotting paper to the sides of the bell jar so that the leaf can get direct sunlight from the top. The dependent variable was the transpiration rate, it was subject to change with respect to relative humidity.
The cabinet pansy, which had no light, was expected to have the lowest rate of transpiration, if any. A number of environmental or internal plant factors determine the rate of water loss in the form of vapour by the plants. Beaker, conical flask, knife, glass rod, thread etc. Dry cobalt chloride paper that is blue in colour turns pink when it comes in contact with water. Adhesion, the property of water molecules that makes them stick to surfaces, like the inside of xylem, and cohesion, the 'sticking together' of water molecules by hydrogen bonding are the 'A' and the 'C. Determine the total area of the leaf by graph paper method and then calculate the total number of stomata of the said leaf. Record the initial reading from the scale and final reading after the tracing of leaf.
The transpiration rate was measured through the loss of weight and then was calculated from there to get the total percent weight loss. Step 2 Leave the setup for 48 hours and record the amount of water loss. Take the initial weight of the sets. Take some mercury in the beaker and keep in it the lower end of the capillary tube. Record the initial and final weights before and after transpiration in each set to determine the amount of water transpired by the leaf of each set. Experiment: To demonstrate the transpiration from the leaf surface, four banyan leaves are taken.
Finally, transpiration index is calculated by the relative efficiency of the rate of transpiration with that of physical evaporation. Fill the apparatus with water and keep some water in the reservoir. Loss of water through transpiration can be facilitated by the opening and closing of the stomata depending on environmental conditions. Conical flask-water-oil-leaf experimental sets 2. Apply the vaseline on the cork and hole to make it air-tight To make the cork region air-tight oil cloth may also be used instead of vaseline. Results: Mercury level rises in the capillary tube because of the pull or suction exerted by the transpiration process.