| Explore | From our experiences outside of school we know that all plants go through photosynthesis. We discovered in class that with carbon dioxide photosynthesis can occur. Carbon dioxide contains gas which is in the air around us. Most oxygen does not dissolve in water, but it clusters together to form bubbles. Carbon dioxide is polar so it dissolves in water. Lastly, photosynthesis contains of water, light, oxygen, and carbon dioxide. Some questions we have about plants that interests us are, will colored water affect the rate of photosynthesis. Also, does the amount of water affect the plants process. |
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| Research Question | During this investigation, our research question question stated, if another color of light will affect photosynthesis? The question included a hypothesis and a prediction in order to support our claim. Our hypothesis stated: if the color of the light is different, then photosynthesis will occur at different rates. We identified our question by looking back at our prediction that we created before the experiment took place. Our prediction explained: the rate of photosynthesis of the plant under the blue light will have a higher rate of photosynthesis than the one under the green light. We thought the blue light would have a higher rate of photosynthesis because the blue light has a higher wave length than the one in the green light. The question fits our topic because we know that in order for photosynthesis to occur, light, carbon dioxide, oxygen, and water must be present. |
| Predictions | Our prediction was if the rate of photosynthesis of the plant under the blue light will be higher than that of the plant under the green light. We think this because in the textbook we looked at the graph to see what color lights would affect the rate of photosynthesis. We saw that blue was one of the colors with the highest rates and green was one of the colors with the lowest rates. Also, we know that blue light is absorbed and green light is reflected that is why we would think that would occur. |
| Experimental Design | Our plan in this experiment was to test the effects of different color lights on photosynthesis and leaf disks. To do this we prepared the leaf disks using the leaf disk flotation method where you use a syringe to vacuum the air out of a leaf disk to make them sink, putting twelve in each cup filled with water. You then put cellophane of different colors, in this case blue, green and colorless, and put these cups under light. The variables we tested were different colored lights. The variables we measured and observed were blue, green, and colorless light effects. The variables we kept constant was the amount of exposure to light that each cup got. We recorded our data in intervals of 5 minutes up to 10 minutes before switching to every two minutes where we looked at how many leaf disks were floating in each. |
| Conclusion | Based on our research the color of light being absorbed by the leaf disks did cause a change in the rate of photosynthesis, the rates being lowest among the leaves under the blue light and highest among that of the colorless cup, the green cup did have higher rates than the blue but still lower overall than the leaves in the cup in colorless light. For our results possible explanations for some outcomes could be that we vacuumed the leaf disks too much and actually ruined the structure of the leaf. These things support our claim because we know that clear light will be absorbed much better than light of a different color would be absorbed such as green and blue light. Future experiments could be that we test the affects of other colors of lights on either the same type of leaf or different types of leaves. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Arthur L. Johnson High School |
| Session | Fall 2017 |