AP Biology -- John Burroughs School -- M. Bahe
Follow-up For AP Lab #11:
The Effect of Environmental Variables on
Transpiration Rates in Three Species of Plants
You will be assigned one of the pairs of environmental factors below:
Fan
Humidity
Two Species
Colin
Humidity
Fan
Two Species
Jharnae
Vaseline Both
Dark
Two Species
Nick
Dark
Vaseline Bottom
Two Species
Chase
Fan
Vaseline Bottom
Two Species
Emma
Humidity
Vaseline Bottom
Two Species
Jacqueline
Vaseline Both
Fan
Two Species
Eliza
Fan
Vaseline Both
Two Species
Sina
Fan
Vaseline Both
Two Species
Max
Vaseline Bottom
Humidity
Two Species
Spencer
Dark
Fan
Two Species
Caroline
Humidity
Dark
Two Species
Sarah
Humidity
Dark
Two Species
Emily
Vaseline Bottom
Fan
Two Species
Faraz
Dark
Humidity
Two Species
Lindsay
Dark
Vaseline Both
Two Species
You will have three questions to address:
1. What is the effect of (IV #1) on the transpiration rate of two species of plants?
2. What is the effect of (IV #2) on the transpiration rate of two species of plants?
3. What is the effect of plant species on transpiration rate? Is there a relationship among the number of stomates, the
amount of transpiration, and the environment in which each plant species evolved? (This question is the same for
everyone).
Considerations:
In addition to our masses on each day, we also have information on the (1) density of stomates for each plant type
and (2) total surface area for each individual plant. How can you incorporate this data into your evaluation of the hypotheses
and analysis of the data?
For each question, you must:
1.
2.
3.
4.
5.
6.
Ø
State the question clearly
State your original research hypothesis. Recall, a research hypothesis is in the form of:
a. (1) a tentative explanation (a claim) along with (2) an action to test the plausibility of the explanation and (3)
the prediction of the results that would provide evidence to support your claim.... or stated another way
b. "If this is why something is happening and I do this to test this idea then I expect that this will happen...." or
mostly simply . . .
c. Hypothesis, Methods, and Prediction
At least one properly constructed data table. This table should be made with Excel and include
a. a complete title
b. heading and units on your columns and or rows
c. average data values/calculations necessary for your question; make sure to include control values along
with values for your independent value; include data for both plants
d. proper format (centered values, borders on cells, etc.)
At least one properly constructed graph. Each graph should be made on Excel and include
a. a complete and proper title
b. labels and units on your axes
c. a key for your lines
**Calculate the required statistics (Standard Deviation, SEM, & 95% CI). Add ______________________ to your
graphs.**THIS DIRECTION WILL BE CLARIFIED IN CLASS
A short discussion/analysis of your results that includes
a. Discussion of hypothesis as it relates to your data.
1) Restate the hypothesis
2) Use quantitative data (numbers with units) from the experiment to describe the results. Use
the data to answer the question as it relates to the hypothesis
3) How did your hypothesis hold up? Was the hypothesis supported? Can you accept the
hypothesis or must your reject it? Was this correct or incorrect reasoning based on your
experimental data?
b. Your best explanation of the results.
1) Explanation of what happened
2) Why did you get the results you did?
c. Discuss the validity of your results.
1) Is your data valid? Is there any questionable data? Were there factors you could not control?
2) Explain how any errors may have affected results.
Remember: Always write in the third person (no use of I or we)