Team Green MADDY CAMERON MARYJO HANNAH

Background Information  Total net carbon fixation (the conversion of CO2 to organic compounds, like glucose) is reduced by 45% in the water stressed plants compared to well-watered plants.  Water stress also increased the leaf's susceptibility to photoinhibition (light- induced reduction of photosnythetic capacity).

Purpose and Hypothesis  The purpose of this experiment is to find out if the amount of water that the plant receives effects the rate of photosynthesis.  If the amount of water received by a plant is restricted, then the rate of photosynthesis will decrease.

Basic Procedure  In order to complete this experiment we had to first Plant four basil plants and water normally until plant is visible.  Water each plant for three days but when watering, water plant #1 & #2 with 10 mL of water each day with a graduated cylinder.  Then, water plant #3 and #4 with 30 mL of water each day using graduated cylinder.  Finally, after four days remove the leafs from each sample and determine the photosynthesis rate by using the floating leaf assay experiment.

Basic Procedure Continued  Leaf Assay Procedure 1. Prepare 300ml of bicarbonate solution for each trial. 2. Add one drop of dilute liquid soap to the bicarbonate solution 3. Cut out 10 pieces of basil leaf using a hole punch. 4. Remove top of syringe barrel and carefully place leaf disks into the syringe. 5. Push down on the syringe so most of the air is out of the syringe. 6. Put the syringe in the bicarbonate solution and tap the syringe to suspend the leaf disks in the solution. 7. Hold finger over syringe opening, draw back on plunger to create a vacuum 8. Hold the vacuum for 10 seconds while swirling the leaf disks to suspend the solution 9. Let off the vacuum 10. Repeat steps 8 through 10 for 2 or 3 times to get leaves to sink 11. Remove the syringe barrel and pour the solution into a plastic cup. 12. Add bicarbonate solution to a depth of about 3 centimeters in the cup 13. For a control group infiltrate leaf disks with a solution of only water with a drop of soap 14. Place both cups under a light source and set timer for 10 minutes 15. Record the number of floating disks and at what time they began to float.

Results P Value:

Data- Interpretations  There is a slight correlation in the data, but not enough to make it significant. The change in a plants photosynthesis rate due to the change in water given is only due to chance

Limitations and Implications  The limitations for the experiment, were having to cut the days for treatment from 2 weeks of treating to 3 days of treating. Another limitation to the experiment was the light for the floating leaf disk assay experiment was artificial and not strong natural sunlight.  The implication to the experiment was that only spicy globe basil was tested to see if the amount of water affects the rate of photosynthesis and not seeing if other plants would be affected differently. Also the period of time that the rate of photosynthesis was affected may differ from the three days that the plants were treated.

Preparedness/ Errors  Our group was very prepared for this experiment, we had all the materials we needed and we planted the spinach seed and were all ready to start. However, like all experiments, there were some errors. Some of our errors included..  Thinking that other people were watering the plants in the group but no one was actually watering them  Since no one was watering them and they did not grow that set us back in the amount of time, so we didn't have the full 2 weeks to experiment with  Unequal distributions of root systems when we cut the basil plants

Works Cited  Works Cited "Chloroplast." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 5th ed. Farmington Hills, MI: Gale, Science in Context. Web. 25 Mar Delgado, E., M. Parry, J. Vadell, D. Lawlor, and A. Keys. "Effect of Water Stress on Photosynthesis, Leaf Characteristics and Productivity of Field- Grown Nicotiana Tabacum L. Genotypes Selected for Survival at Low CO2." Journal of Experimental Botany 43.8 (1992): Oxford Journals. Web. 10 Mar Lu, Congming, and Jianhua Zhang. "Effects of Water Stress on Photosynthesis, Chlorophyll Fluorescence and Photoinhibition in Wheat Plants." Australian Journal of Plant Physiology(1998): Web. 10 Mar "Photosynthesis." Experiment Central: Understanding Scientific Principles Through Projects. M. Rae Nelson. Ed. Kristine Krapp. 2nd ed. Detroit: UXL, Science in Context. Web. 25 Mar Williamson, Brad. "Exploring Life Community." The Floating Leaf Disk Assay for Investigating Photosynthesis (2011). Print.