Student Name __________________________ Date____________
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.