| Explore | Outside of school, we know that plants can grow in many different environments. There are many different types of plants which react to climate differently and grow at different rates. Plants also vary in species. In class, we have conducted experiments supporting that for photosynthesis to occur, water, carbon dioxide, and light have to be present. We also know that photosynthesis is the process in which plants make their own food to grow. We were interested in how plants grow and how different conditions can effect how fast plants grow. |
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| Research Question | We wanted to test the effect of different temperatures on photosynthesis. We came up with our questions based on what we wanted to learn more about and discover. This question fits what we know about photosynthesis because we already investigated and know that we need light and carbon dioxide for photosynthesis. We wanted to figure out how much temperature impacted photosynthesis. |
| Predictions | The predictions we made for our experiment of the effects of temperature on photosynthesis were that leaf disks would float faster in a warmer water and slower in cooler water. We said this because with background research, we have figured out that if temperatures are too cool, plants can not photosynthesize. We thought that since our temperatures were at a cooler temperate in one cup, the warmer and room temperature cups would float faster then the cooler cup. |
| Experimental Design | In our experiment, we will test the effects of temperature on photosynthesis in spinach leaves. The plan for this is to separate an even amount of distilled water with baking soda and three drops of dish soap in three different cups, one warm at 47.8 (C), one room temperature at 21.2 (C), and one cooler at 15.8 (C). From there, we put 6-12 spinach leaf disks in each cup along with a thermometer. All cups were put under a light source. In this, we will measure how fast the leaf disks float in each different temperature cup. The variables that remained constant were the cup size, the amount of leaf disks, the level of water, and the distance and intensity of our light source. The variables we tested were different temperatures in each cup and how it effected the flotation of the leaf disks. We recorded our data every two minutes in a data table and after all the information was collected, in a graph. We recorded the initial temperature of each cup and how many disks were floating and not floating every two minutes. |
| Conclusion | The claim we made from our experiment is that the rate of photosynthesis increases when the water in the experiment is at room temperature. An explanation we have for this is because the plant we used was spinach leaves, which tends to grow in the temperature we had our water at. Because the spinach leaves were already accustomed to this temperature, photosynthesis occurred much faster in this cup. Since photosynthesis needs light, water, and carbon dioxide to occur, we had to make sure the experiment we conducted contained these three components. Our data, with two leaves floating after ten minutes and three at twelve minutes in only the room temperature cup, is supported by other scientific evidence, supporting our claim of the the components needed for photosynthesis. In the cool and warm cups, after fourteen minutes, no leaf disks floated. When we put these concepts together, we concluded that temperature can effect the rate of photosynthesis. This data supports our claim because the leaf disks floated in only the temperate they were accustomed to. Further experiments could be done to continue this lab. For instance, we could change the plant and test the hypothesis that different plants react to different temperatures. Also, we could have more drastic changes in temperature and see how that will effect its rate. Because of these many factors, we were able to conclude that the rate that photosynthesis occurs can be effected by temperature changes and will increase at room temperature. |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | Arthur L. Johnson High School |
| Session | Fall 2017 |