Photosynthesis Lab

Background Information The purpose of this experiment is to monitor how different plant species affect photosynthesis. To measure how the different plants affected photosynthesis, we measured the levels of carbon dioxide. The question that we researched was: How will different types of plants affect photosynthesis and rate of respiration? We believe that if cedar is placed in the chamber and undergoes photosynthesis then the carbon dioxide levels will go decrease the most because the most photosynthesis will occur. We also agree that no matter what plant is in the chamber, the carbon dioxide levels will go down. During photosynthesis “When the plant makes the glucose molecule, it gets the carbon and oxygen atoms it needs from carbon dioxide,

The plants we used were rosemary, cedar, and boxwood. For accurate results, it is best to use the same amount of each plant species sample. Along with the plant samples, we needed a carbon dioxide sensor, a sealed bottle that the sensor can go into, and access to the outdoors. After gathering the materials, we placed the first sample, rosemary into the chamber with the carbon dioxide sample. We placed the chamber with the plant sample outside where the sun could reach it. We waited fifteen minutes and let the sensor collect the carbon dioxide levels inside the bottle. At the end of fifteen minutes, we brought it back into the building and removed the plant pieces. After this first run, we repeated the same exact steps for cedar, boxwood, and a control. For the control, we measured the carbon dioxide levels of a bottle outside with nothing inside it. In order to get the most accurate results possible, we also ran another trial using the same

All of the plants did reduce the levels of carbon dioxide in the bottle, but there was not a significant enough difference to prove that the plant species has an effect. Based on this result the answer to our research question is no: the plant species does not affect the levels of carbon dioxide. It does make sense that the carbon dioxide levels went down because carbon dioxide is “employed by plants in the photosynthesis of carbohydrates,” and there taken in by plants (Encyclopædia Britannica). Although our hypothesis specific to cedar was proven to be false, considering no plant had a vastly different effect on the carbon dioxide levels, our prediction about the decrease of carbon dioxide was correct. All the carbon dioxide levels did, in fact, decrease. Even though that hypothesis was proven correct, there is still a possibility that there is some error in our results. One source of error could have been that on the first day of testing it was very cloudy outside and then on the second day it was very sunny. This could have caused the rate of photosynthesis to be much less on the first day than the second day because it received less sunlight on that day. Another source of error could have been the fact that the bottles were not thoroughly washed before a different plant sample was used in them. There could have been residual matter