How does light intensity affect the rate of photosynthesis? Prediction: If we were to expose a plant to a higher intensity of light, then it will allow the plant to undergo the process of photosynthesis at a faster rate.

Experimental Design Materials: 2 Cardboard Boxes (2 plants per box) Four Potted Plants type: Dracaena Amount of water- 75 ml each day Sunlight Tissue Paper 4 Paper plates Beaker Variables: - Independent Variable- Light intensity - Dependent Variable- Rate of photosynthesis - Control Variable- Plants, amount of soil, amount of watering, etc.

Procedure 1.Construct your box. You can do this by cutting two squares of equal length in the cover. Make sure there is enough space for each plant to fit through the holes. Do this for both boxes. 2.Place two plants in each box. 3.Plant A will have no tissue paper over the hole. Plant B will have one sheet of tissue paper covering the hole. Plant C will have 2 sheets of tissue paper over the hole. Plant D will have 3 sheets of tissue paper over the hole. 4.Put the boxes on a table in direct sunlight where they will both receive equal amounts of sunlight 5.You will water the plants with 75 ml every other day. 6. Red Phenol Test: Mix two solutions of 100 ml of water with a quarter of a teaspoon of red phenol in each. In the second mixture, blow carbon dioxide into it until it turns yellow. Take 10 leaf samples from each plant, then divide them by 8 cylinders with five leaf samples in each, with 5 ml of two of the solutions each. Stir the leaf samples into the solution and observe the change of color in each solution. 7. Chart findings 8. Retest in different if the first design is faulty 1.Construct your box. You can do this by cutting two squares of equal length in the cover. Make sure there is enough space for each plant to fit through the holes. Do this for both boxes. 2.Place two plants in each box. 3.Plant A will have no tissue paper over the hole. Plant B will have one sheet of tissue paper covering the hole. Plant C will have 2 sheets of tissue paper over the hole. Plant D will have 3 sheets of tissue paper over the hole. 4.Put the boxes on a table in direct sunlight where they will both receive equal amounts of sunlight 5.You will water the plants with 75 ml every other day. 6. Red Phenol Test: Mix two solutions of 100 ml of water with a quarter of a teaspoon of red phenol in each. In the second mixture, blow carbon dioxide into it until it turns yellow. Take 10 leaf samples from each plant, then divide them by 8 cylinders with five leaf samples in each, with 5 ml of two of the solutions each. Stir the leaf samples into the solution and observe the change of color in each solution. 7. Chart findings 8. Retest in different if the first design is faulty

Research Factors Affecting the Rate of Photosynthesis This website provided us with the various factors affecting photosynthesis, some being temperature, water, light levels, and nutrients. This website provided a copy of an experiment similar to what we did, which helped us to make our prediction. Plants located outside grow faster compared to being located inside, for there is greater sunlight outside. They grow faster with increased sunlight until they hit a breaking point, where no matter how much sunlight they receive, they will not be able to photosynthesize any faster.

Findings None of the type 2 (red) solutions changed color- meaning that photosynthesis is taking place and producing oxygen Each of the type 1 (yellow) solutions became more peachy colored. Solution A1(control) became most peachy while all others, B1, C1,D1, were more of a yellowish shade. There was a definite gradation in redness, starting with A1 at the deepest shade of peach to D1 at the lightest shade of peach. None of the type 2 (red) solutions changed color- meaning that photosynthesis is taking place and producing oxygen Each of the type 1 (yellow) solutions became more peachy colored. Solution A1(control) became most peachy while all others, B1, C1,D1, were more of a yellowish shade. There was a definite gradation in redness, starting with A1 at the deepest shade of peach to D1 at the lightest shade of peach.

Data Analysis These findings show that photosynthesis was present in all of the subjects and was at the greatest rate in the control plant and decreased with every extra sheet of tissue paper we covered the boxes in.

Conclusions Our findings were similar to our research findings. Increased light intensity causes increased rate of photosynthesis. However we believe our findings could have been influenced from increased mixing of the phenol solutions. More oxygen could have been forced into each of the mixture turning the type 1 (yellow) solutions more peachy colored. Our findings could be discredited from this. The findings agree with our original hypothesis for the rate of photosynthesis did decrease with decreased sunlight. Chart Our findings were similar to our research findings. Increased light intensity causes increased rate of photosynthesis. However we believe our findings could have been influenced from increased mixing of the phenol solutions. More oxygen could have been forced into each of the mixture turning the type 1 (yellow) solutions more peachy colored. Our findings could be discredited from this. The findings agree with our original hypothesis for the rate of photosynthesis did decrease with decreased sunlight. Chart

Thanks to… Our mentor- Jennifer Potratz – Education & Outreach Coordinator of the Botanical Society of America Our mentor- Jennifer Potratz – Education & Outreach Coordinator of the Botanical Society of America

Sources photosynthesis.htm photosynthesis.htm saps.plantsci.cam.ac.uk/records/rec67.htm saps.plantsci.cam.ac.uk/records/rec67.htm ml - ml Phenol Red Test: hesis_BTB.html hesis_BTB.html