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| Research Question | Experiment 1:How does carbon dioxide affect photosynthesis? Experiment 2: How does light effect photosynthesis? Experiment 3: How do different concentrations of CO2 affect photosynthesis? |
| Predictions | Experiment 1:The cups with carbon dioxide will have leaf disks that rise. (floating is an indication of photosynthesis) The cups without carbon dioxide will not have leaf disks that float. Experiment 2: The cups in the light and with CO2 will have leaf disks that float. The cups in the dark (both water and CO2) will not have leaf disks that float. The CO2 Cup that is switched from dark to light will have leaf disks that float. The CO2 cup switched from light to dark will have leaf disks that sink. Both water cups will have no leaf disks floating. Experiment 3: The cups with a greater concentration of CO2 will have a faster rate of leaf disks floating. |
| Experimental Design | Experiment 1:-prepare 3 cups: 1 with baking soda, another with CO2 from breathing into, another just water. -infiltrate leaf disks for each to get out all gas. -place every cup an equal distance from the light. We tested the effect of carbon dioxide on the rate of leaf disks floating. The light exposure, amount of leaf disks, type of water and amount, cup, infiltration method were all kept constant. Experiment 2: prepare 4 cups- 2 with baking soda and water, 2 with water only. Cut leaf disks and perform infiltration. Cover one baking soda and one water cup with a lid and tin foil. Place all cups under the light and check every minute for how many leaf disks are floating. After all the leaf disks float for the CO2 in light cup, switch conditions. Cover the CO2 and water cups in the light and remove the covers from the CO2 and water cups that were in the dark. Record data every minute. The amount of water, type of light, distance from the light, type of cup and coverings, and amount of soap are kept constant. Experiment 3: Prepare 5 cups with different amounts of baking soda (concentrations of CO2).Prepare leaf disks and infiltrate. Place cups near light and record how many leaf disks float per minute. |
| Conclusion | Experiment 1:From the class data (see attached), it can be concluded that carbon dioxide is required for photosynthesis. However, for our group data (thiccbisk), the results for the CO2/baking soda cup showed otherwise. This is likely because there was not enough baking soda (the scales were not precise) and the cups were placed further from the light than the other groups. Later, the effect of different concentrations of CO2 on photosynthesis can also be investigated. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | West High School |
| Session | Fall 2017 |