LAB REPORT EVALUATION MATRIX (Biology 156) GOOD AVERAGE POOR NOT PRESENT (BUT NEEDED) ABSTRACT to include the following (10 pts) 250 words or less _______ ________ _______ _______ problem investigated _______ ________ _______ _______ methods _______ ________ _______ _______ major results _______ ________ _______ _______ conclusions _______ ________ _______ _______ significance of findings _______ ________ _______ _______ TOTAL _______ INTRODUCTION to include the following (20 pts) sufficient background info on organism/system with citations _______ ________ _______ _______ problem clearly defined _______ ________ _______ _______ purpose and goals _______ ________ _______ _______ hypothesis/prediction _______ ________ _______ _______ TOTAL _______ MATERIALS AND METHODS to include the following (20 pts) summary of process _______ ________ _______ _______ purpose of a procedure _______ ________ _______ _______ no excess mundane details _______ ________ _______ _______ TOTAL _______ RESULTS to include the following (15 pts) Tables and graphs clearly labeled _______ ________ _______ _______ Narrative includes summary tables and graphs _______ ________ _______ _______ TOTAL _______ DISCUSSION to include the following (20 pts) interpretation of results _______ ________ _______ _______ Explanation of significance of results _______ ________ _______ _______ has related discussion of results to the goals, hypothesis and purpose of experiment, including conclusions _______ ________ _______ _______ includes citations _______ ________ _______ _______ TOTAL _______ LITERATURE CITED to include the following (5 pts) listed alphabetically _______ ________ _______ _______ cited properly within narrative of paper _______ ________ _______ _______ correct format of citation _______ ________ _______ _______ TOTAL _______ WRITTEN EFFECTIVELY to include the following (10 pts) written clearly _______ ________ _______ _______ Title page _______ ________ _______ _______ use of metric system _______ ________ _______ _______ each paragraph conveys a single major idea and has topic sentence at beginning _______ ________ _______ _______ pages numbered _______ ________ _______ _______ avoidance of I and me statements _______ ________ _______ _______ TOTAL _______ Lab Report Grade ________ Using Transpirometers Must be put in your own word Preparing the Plant (
this can be done hours before the experiment is to be conducted): 1. Select a plant that has a section of stem that is of slightly larger diameter than the tan rubber tubing attached to the pipette tip. 2. Cut the plant off at its base, below where the diameter is slightly larger than the rubber tubing. Immerse cute end in pan of water. 3. Immerse the pipette with rubber tubing attached in the pan of water to remove all air from the pipette and tubing. This may require pinching and squeezing the tubing. All air bubbles must be removed. 4. With the stem submerged, cut the plant again at the point where the stem is slightly larger than the rubbing tubing. Keep the cut stem under water at all times. 5. Slide the rubber tubing over the cut stem. 6. Hold the plant and tubing out the water and check for leaks. If air percolates into the tip of the pipette right away then there is a leak. If there is a leak, resubmerge and try sliding the tubing onto the stem farther. Preparing the Apparatus: 1. Flush the system by opening the screw valve below the reservoir. Flush until no bubbles leave the micropipette then clamp off the micropipette using the spring clamp. Continue flushing until no bubbles are present in the line where the plant will be inserted. 2. Insert the plant and pipette combination into the tube. Wrap a paper towel around the stem of the plant and insert the plant into the open clamp. Clamp just enough to hold the plant upright. 3. Open the spring clamp on the line leading to the micropipette. 4. Open the screw valve on the reservoir just enough for water to drip from the micropipette and then close the screw valve. Blot the drop from the tip of the pipette. 5. If the leaves of the plant are very wet, gently blot them dry. 6. Transpiration should be noticeable within a few minutes as water is drawn from the micropipette. Measuring Transpiration Rates: 1. The micropipette is marked at the 100 ?L point. Students can measure the length to the mark (usually about 88 mm) and then calculate a conversion factor (88 mm/100 ?L). Using the conversion factor they can calculate the volume transpired per unit time. 2. Factors that may affect transpiration rates are light, heat, and wind. However, exposure to extremes of heat or wind may cause the plant to close its stomates rather than transpire more. This might be something to try at the end of a lab period.