1. AP Transpiration Lab Write up requirements Title your Lab: AP Lab Investigation #11 - Transpiration Write Down the guiding question (top of page S135) Pre-lab: What are the safety precautions for this lab? With your lab partner, answer/complete the questions and steps in “Getting Started” pages S137-138. Absent students – complete “Key Concepts 1” at http://www.phschool.com/science/biology_place/labbench/lab9/concepts1.html http://www.phschool.com/science/biology_place/labbench/lab9/concepts1.html Part 1 Stomata Imprint Leaf drawing, surface area, stomata per leaf calculation (refer to lab manual) Absent students – complete the virtual leaf surface area: http://www.phschool.com/science/biology_place/labbench/lab9/calcsurf.html http://www.phschool.com/science/biology_place/labbench/lab9/calcsurf.html

2. AP Transpiration Lab Write up requirements Designing your own investigation (all students) Complete Steps 1-3 on page S141 We are doing OPTION #2 WHOLE PLANT METHOD Clear step by step procedure of how you set it up, and how you will record data I want a research question, hypothesis, variables (what are you examining, for example heat) and PREDICTION. I will be running a control – massing a plant that is removed from water and kept at the front of the room. Data - Data table with date, mass and day # Today is DAY #1 Weigh your plants every day Class data table with variable and percent change in mass per treatment per day

3. AP Transpiration Lab Write up requirements Data Analysis Calculate the surface area of a leaf from your plant (this is using your measurements from the first part/leaf imprint activity) Calculate the percent change in mass over time Graph the change in mass over time (Title, y-axis = mass, x-axis equals day) for YOUR GROUP's data and include Mrs. Brown’s control data Results - you should answer all of these questions in complete sentences and in your own words!!! 1.Calculate the average rate mass change per day for each of the treatments. (Humidity, Light, Fan, Dark, Room – all from the class data) 2.Explain why each of the conditions causes an increase or decrease in transpiration. 3.How did each condition affect the gradient of water potential from the stem to leaf in the experimental plant?

4. AP Transpiration Lab Write Up requirements 4. What is the advantage to a plant of closed stomata when water is in short supply? What are the disadvantages? 5.Describe several adaptations that enable plants to reduce water loss from their leaves. Include both structural and physiological adaptations. 6.Why did you need to calculate the % mass change each day instead of graphing the total amount of mass lost each day? TIPS FOR SUCCESS Write in pen Write legibly Lab is 50 points!!! Due THursday April 21(Period 4) or Friday, April 22(Period 5 & 7)