| Explore | We know that plants do photosynthesis, and that they need light and water to grow. |
|---|---|
| Research Question | How do different colored lights effect the rate of photosynthesis? |
| Predictions | We predict that the purple colored light work best because it will absorb the violet waves the best. |
| Experimental Design | Three cups were filled with water that had been breathed in (for CO2) because this was the best way to get spinach discs to photosynthesize, as supported by a previous experiment. Then, syringes were filled with breath-water and ten spinach discs each, and the air was extracted so that the discs sank. The discs were then deposited into their respective cups. Each cup was placed under a different colored light. Cup one under green light, cup two under purple, and the third under white light. Cup three is the control. Every minute for twenty minutes, the number of leaves floating and sinking in each cup was recorded. |
| Conclusion | In the control cup, all ten discs rose. In the purple cup, seven out of ten rose, and none rose in the green cup. This could be because spinach discs absorb white light the best, and so is best able to use that to photosynthesize. Because green light is reflected, it is not able to be used for photosynthesis. Some purple light is absorbed, so photosynthesis using it is possible. To expand, one might try this experiment using different plants to see if the rate of photosynthesis is impacted by that. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | St Joseph's Academy |
| Session | Fall 2017 |