Be sure to remove all flowers and buds Do not water your plant any more until

Be sure to remove all flowers and buds do not water

This preview shows page 8 - 11 out of 11 pages.

plastic bag and tie the bag around the base so that only the leaves are exposed. (Be sure to remove all flowers and buds.) Do not water your plant any more until you finish your experiment! You can also keep the plant in the plastic pot and place it in the plastic bag.Step 3 Determine the mass of each plant and then its mass for several days under your chosen environmental condition(s).Step 4 Create a data table to collect data. Record the mass daily. Remember to include any leaves or flowers that have fallen off. Return the plant to your experimental setup as quickly as possible.Calculations: Determining Surface Area and Transpiration RatesStep 1 In the first part of this lab, you were asked to investigate methods to calculate leaf surface area and the surface area of all the leaves on a plant. The grid provided will be helpful. Determine the total surface area of the leaves in cm2and record the value on thatpage.Step 2 Calculate the rate of transpiration/surface area. Show your work below.Step 3 After the entire class agrees on an appropriate control, subtract the control rate from theexperimental value. Record this adjusted rate. Show your work below:Page 8 of 11
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AP BiologyLabUnit 5 - Enzymes & MetabolismStep 4 Record the adjusted rate for your experimental test on the board to share with other lab groups. Record the class results for each of the environmental variables investigated. These dataneed to be included in an attached data table. Make sure to include column and row headings as well as appropriate units.Step 5 Graph the class results to show the effects of different environmental variables on the rate of transpiration and attach. Make sure to include a properly formatted title, axis labels with units, and a legend. Use a straight edge and use graph paper. You may need to convert data to scientific notation with all numbers reported to the same power of 10 for graphing purposes.Analyzing Results1.How was the rate of transpiration affected by your choice of experimental variable as compared to the control?2.Explain how each of the variables tested affected transpiration rates. Think about how each tested variable might have simulated a real environmental condition to which plants are exposed.3.Based on data collected from different lab groups, which environmental variable(s) resulted in the greatest rate of water loss through transpiration? a.Explain why this factor might increase water loss when compared to other factors. Page 9 of 11
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AP BiologyLabUnit 5 - Enzymes & Metabolism4.Why did you need to calculate leaf surface area to determine the rate(s) of transpiration?5.What structural or physiological adaptations enable plants to control water loss? You’ll need to do a little research here. Your textbook is a great resource. Describe3 adaptations.6.Create a diagram with annotation to explain how the TACT (transpiration, adhesion, cohesion, tension) mechanism enables water and nutrients to travel up a 100-ft. tree. Predict how a significant increase in ambient (environmental) temperature might affect the rate of transpiration in this tree. Explain your prediction in terms of TACT and the role of guard cells in regulating the opening and closing of stomata.Evaluating Results1.Was your initial hypothesis about the effect of your environmental variable on the rate of transpiration supported by the data you collected? a.Why or why not?Page 10 of 11
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AP BiologyLabUnit 5 - Enzymes & Metabolism2.What were some challenges you had in performing your experiment? a.Did you make any incorrect assumptions about the effect of environmental variables on the rate(s) of transpiration?Page 11 of 11
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