| Explore | We know from class that the amount of carbon dioxide increases the rate of photosynthesis. We tested our breath and baking soda as sources of carbon dioxide. We wondered if we could use different sources of co2. |
|---|---|
| Research Question | What is the effect of dry ice concentration on the rate of photosynthesis? |
| Predictions | We weren't sure if the co2 in dry ice would help or harm the rate of photosynthesis in the spinach leaf disks. We were worried that the old temperatures would harm he plants. |
| Experimental Design | We used the same leaf disk procedure from the previous labs to make 4 cups. Cup 1 had no added co2, cup 2 had 3.0 grams of dry ice, cup 3 had 6.5 g of dry ice and cup 4 had 8.6 grams. We mixed hot water with each dissolved solution of dry ice so that each cup had 100 ml of water at 20 degrees Celsius. We then placed the cups under a 4 ft grow light for several hours recording the number of floating disks. |
| Conclusion | We investigated the effect of dry ice concentration on the rate of photosynthesis in leaf disks. Bryan predicted that the leaf disks would be harmed by the dry ice. However, the data showed the opposite. The cup with the most dry ice, 8.6 g floated all their leaf disks very quickly, by 10 minutes all the disks were floating. The cup with 6.5 and 3.0 grams floated next and were all floating by 85 minutes. This shows that as the concentration of co2 increases, so does the rate of photosynthesis. If we were to continue testing, could we find the amount of co2 that no longer changed the rate of photosynthesis. What is the maximum rate of photosynthesis using dry ice? |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Jefferson City High School |
| Session | Fall 2016 |
