| Explore | From basic understanding we know that plants don’t eat to get energy and can not move. From our experiences in this class we have learned a lot about the process of photosynthesis. We know they need CO2, H20, and Light energy to produce glucose and oxygen. This process is done in the chlorophyll. We wonder about how plants grow to be so big. |
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| Research Question | We want to test the relationship between photosynthesis and the color of the leaf of a plant. We know that plants use photosynthesis to create glucose that they need to create energy and organic compounds however we know that photosynthesis requires light and the reason plants have different colors sometimes is because of the wavelengths they absorb. We question how this difference will affect the rate of photosynthesis. We came up with this question with the help of our mentor giving us some questions to think about and eventually we decided that this question would be good to experiment. |
| Predictions | Our variable is the rate of photosynthesis in relation to the color of the leaf. We have purple cabbage and spinach leaves in our experiment. Our outcomes consist of Purple photosynthesizing faster than the spinach, spinach photosynthesizing faster than purple cabbage and, finally spinach and purple cabbage photosynthesizing at the same rate. We predict that they will photosynthesize at the same rate. We say this because even though they absorb different colors they will still be absorbing light so photosynthesis will still happen. |
| Experimental Design | Our plan is to test the rate of photosynthesis depending on the color of the leaf. We plan on doing 2 trails one with just a normal light bulb and another with a normal light bulb and a UV light bulb. For the experiment you will need 4 cups, distilled water, baking soda, a syringe, soap (optional helps with vacuum), 10 disks of spinach leaves and 10 disks of purple cabbage for trial I and 20 disks (10 for each light) of spinach leaves and purple cabbage for trial II, a hole puncher, get 2 lamps (one with a normal bulb and one with a UV light bulb, a stopwatch, a paint brush. To start off make your solution of water and a teaspoon of baking soda and stir it together for around 8-10 seconds. Next start cutting your disks for the first trial try to make sure you don’t damage the leaf when hole punching. After vacuum the air out of the leaf with the syringe. Pour your solution into each cup and then put the leaves in. If done correctly the leaves should sink to the bottom in every cup. Put it close under the lights and start a timer with the stopwatch for 15 minutes. Every minute count how many floated for the 15 minutes and by the end you should have your results. The constant variables are the light, time, solution, amount of disks. Record your data using a data table that tracks the amount floating and not floating for each cup. |
| Conclusion | From our experiment we can conclude that the spinach leaves which are green colored photosynthesize faster than purple cabbage under normal light conditions and uv light conditions. The possible explanation for these results is that the purple cabbage leaves don’t absorb as much uv and normal light as the spinach leaves or during our experiment we noticed that the purple cabbage was thicker than the spinach leaves which could explain the slower rate of photosynthesis. Our experiment supports our claim because after 15 minutes of every trial and light the spinach leaves had a major statistical rate of photosynthesis compared to the purple cabbage leaves. With spinach leaves having almost all of the discs floated by the end while the purple cabbage leaves never having more than 5 floating leaf disks. Which proves that spinach leaves photosynthesize faster compared to purple cabbage under all conditions of light. Another experiment we could do to expand off this is to create an experiment that tests the rate of photosynthesis depending on the thickness of the leaf. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| Teacher Name | Shirl Shawhan |
| School Name | Hunterdon Central Regional High School |
| Session | Fall 2023 |