AP Lab 9 Rubric (30 points)

Title, Abstract, Results (summary table, summary graph, trend paragraph), conclusion and references.

Point Value



1) Title: descriptive (IV/DV present)


2) Abstract: Can’t exceed 250 words

a. background information (definition and purpose of transpiration in vascular plants)

b. procedure description –  very general

c. Results – must include statistics...  average rates of water loss per minute compared to     control

d. conclusion – relates to results of overall experiment (most water loss which conditions, etc)




4) Results:

a. Your table data and Summary data table – Title, descriptive units, no vertical lines, not confusing


b. One summary graph – If x-y scatter used, must show trend line and equation, y = mx +b, titles descriptive, axes labeled with units; trendline key


c. Trend paragraph – must include info that describes what is in data tables and graphs. Includes average rate of water loss/min of all conditions and comparison calculations  (ex. wind 4x the water loss, etc).


d. labeled (hand drawn colored) picture of stem cross section


5) Conclusion/Discussion: Explanation of results – must relate background info and results (Why was it necessary to calculate leaf surface area for your data analysis? Explain why each of the conditions causes an increase or decrease in transpiration compared to the control. How does each condition affect the gradient of water potential (in general) from stem to leaf to air in experimental plant. Is there any advantage for a plant to close stomata, are there any disadvantages? Talk about the adaptations that enable plants to reduce water loss from their leaves (there are several structural as well as physiological adaptations... HINT: Abscisic acid). Discuss the cell/tissues


6) References –  2 min APA Format