How does different amounts of Round Up Effect the Rate of Photosynthesis? Jackson McNally, Travis Webb, Lauren Meyers ETM and ACB Academies Introduction Results Conclusion Photosynthesis is the process in which plants and some other organisms use sunlight to synthesize food from carbon dioxide and water. We were curious to see if different concentrations of Round Up herbicide would slow down, or even stop photosynthesis. Methods Claims/ Evidence Acknowledgements Dana Dudle- DePauw University Christine Winstead- West High Procedure Materials 4 fast plants (3 tested 1 control) 1 bottle of Roundup 15 plastic cups Syringe Beaker Bicarbonate solution Large Light box Small Light box Hole puncher 2 specimen dishes Timer 1.Plant fast plants. Wait 3-5 days for the plants to begin growing before starting experiment. 2.After waiting 3-5 days, fill 4 cups with 80ml of water. 3.Then measure 3, 6, and 9, ml of round up with the syringe and put each in a separate cup leaving one for a control. Make sure to label the cups in order to prevent mix-ups. 4.After doing this, label the 4 plants with 3ml, 6ml, 9ml and control. 5.Dump the water solution with the matching amount of roundup labeled on the plant in each reservoir underneath the fast plants. 6.Place back in large light box. Wait 24hrs and repeat steps 2-5 for 5 days. 7.After 5 days, take hole puncher and punch out 10 leaf “disks” of each plant. 8.Take one of the groups of ten disks from one plant and put them into the syringe with water and a single drop of dish soap. 9.Put your finger on the tip of the syringe and pull the plunger repeatedly until all 10 leaf-disks have sunk. 10.After this dump all contents in syringe into a plastic cup with 200ml of bicarbonate solution. 11.Set specimen dishes upside down on top of each other inside the light box. Set the cup with the bicarbonate solution and leaf disks on top of the specimen dishes beneath the light bulb. Begin timing to see how long it takes for the disks to surfaces. This determines the rate of photosynthesis. 12.When a leaf-disk surfaces, record the time in a data table. This determines the rate of photosynthesis. The earlier the leaves come up the better photosynthesis is working. 13.Once all have surfaced, dump out contents and repeat steps 8-12 with other concentrations. 14. Be sure to analyze the data and come to a conclusion about the experiment. Look at the appearance of the plant as well. Look at the size, number of leaves, color etc. We have concluded that roundup effectively kills plants which stops photosynthesis completely. We noticed that the ones with more roundup looked considerably worse than the others. Many of the leaves were brown and limp. The plants themselves weren't very tall either. We figured that the ones with a small amount of roundup would still come up, just not as quickly as the control. However, even the small amounts of herbicide completely stopped photosynthesis. This supported our claim that the herbicide would stop photosynthesis. Discussion Our hypothesis stated that we believed larger concentrations of Round Up would affect the plants’ photosynthesis in a negative way. Our claims turned out to be correct. Though none of the plants performed photosynthesis, the ones with the larger amounts of Round Up were smaller, the leaves were brown, and they were all around weaker looking. After starting our experiment, we found out some things that we could have done better. First of all, we could have used a smaller dosage of herbicide, because even the smallest amount completely killed the plant. Second we could have used better equipment because our syringe blew up, multiple times. Lastly, we would have done multiple trials, if we had the time. Time for Leaf Disks with Different Amounts of Herbicide to perform photosynthesis.