| Explore | Plants need carbon dioxide, sunlight, soil, water, and nutrients in order to grow. They produce oxygen. They go through the process of photosynthesis, which uses sunlight energy to produce glucose from carbon dioxide and water. We also know plants are pigmented green because of chlorophyll a and b. In class, we discovered that plants change their colours seasonally, for example during Autumn, leaves on trees change their colours to yellow, orange, and red because the plant stops making chlorophyll, which is a green pigment that traps light energy from the sun, in order to conserve energy. A question about plants that interest us is that why leaves fall in the Winter. |
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| Research Question | Investigation: How do different coloured lights affect photosynthesis using a leaf disk floatation method? Light plays a major role in photosynthesis, so we would like to figure out whether different coloured lights would affect the process. |
| Predictions | Colours provide different strengths of energy, we believe that out of the three colours red green and blue, red would be the most effective because red attracts the most heat. Chlorophyll a and b help plants meet their energy requirements by absorbing light from the colour light spectrum. |
| Experimental Design | Materials: - Spinach cut into equal sizes of 30 disks - 3 cups filled with equal amounts of distilled water - 3 syringe cylinders - 1 Lamp - 3 coloured paper filters (red, blue, and green) Procedure: Cut up 10 small equal circular pieces of spinach leaves Fill three cups with equal amount of distilled water Pour about 10 leaf disks into the syringe cylinder with water filled to three quarters Remove the gases by pulling the plunger and slowly letting it go while the tip of your finger is blocking the airway. Once the disks start to sink that is how you know there is no more air bubbles within the spinach disks. (repeat process 3x) Then pour the leaf disks back into the cups Set up the lamp with same voltage energy light, then place a coloured filter paper on each cup. Observe the spinach disks for 20 minutes and record results The variables that we will test are the independent variables which are the coloured filter papers and the dependent variables which are the spinach disks. We measure and observe the dependent variable which is the spinach disks. We will keep the dependent variable constant. We record our data by observing the floatation of the spinach disks after every minute for 20 minutes. |
| Conclusion | |
| Investigation Theme | POS |
| Grade Level | High School Students (Grades 9,10,11,12) |
| School Name | David & Mary Thomson C. I. |
| Session | Fall 2017 |