Photosynthesis Experiment

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Distance from light/mm| Colorimeter reading/arbitrary units| | Algal balls solution| Hydrogen carbonate solution|
| 1| 2| mean| 1| 2| mean|
0| 0.52| 0.52| 0.52| 0.50| 0.50| 0.50|
250| 0.52| 0.45| 0.49| 0.59| 0.63| 0.61|
500| 0.50| 0.49| 0.50| 0.52| 0.55| 0.54|
750| 0.47| 0.55| 0.51| 0.54| 0.53| 0.54|
1000| 0.58| 0.56| 0.57| 0.52| 0.54| 0.53|
Results
Results

The results do not show the general relationship between light intensity and photosynthesis that could normally be seen had the experiment taken place without errors. The graph should show an increase in arbitrary units the further away from the light source the beaker is because the greater the distance from the light source, the lower the light intensity and so less photosynthesis would take place in the algal balls. This would result in more CO2 being present because it wouldn’t be being used up during photosynthesis. The decrease in CO2 in the solutions nearer the light source would cause the hydrogencarbonate indicator to change colour to purple/red and therefore the darker colour would produce a lower reading on the colorimeter because the blue filter would reflect the darker colour, letting less light through. In order to gain these results if the experiment were to be repeated, it must be done in a dark room where the artificial light is the only light source available to the algal ball beakers. This will enable a more reliable reading to be taken as the beakers further away from the light source will not have the light from the window to enable them to photosynthesise as much as the beakers close to the light. The trend which was expected to be seen was that the light intensity is a limiting factor in photosynthesis. The greater the intensity of light, the more the plant/algae cells photosynthesises and so takes up more carbon dioxide as the rate is increased. The results do not show the general relationship between light intensity and photosynthesis that could normally be seen had the experiment taken place without errors. The graph should show an increase in arbitrary units the further away from the light source the beaker is because the greater the distance from the light source, the lower the light intensity and so less photosynthesis would take place in the algal balls. This would result in more CO2 being present because it wouldn’t be being used up during photosynthesis. The decrease in CO2 in the solutions nearer the light source would cause the hydrogencarbonate indicator to change colour to purple/red and therefore the darker colour would produce a lower reading on the colorimeter because the blue filter would reflect the darker colour, letting less light through. In order to gain these results if the experiment were to be repeated, it must be done in a dark room where the artificial light is the only light source available to the algal ball beakers. This will enable a more reliable reading to be taken as the beakers further away from the light source will not have the light from the window to enable them to photosynthesise as much as the beakers close to the light. The trend which was expected to be seen was that the light intensity is a limiting factor in photosynthesis. The greater the intensity of light, the more the plant/algae cells photosynthesises and so takes up more carbon dioxide as the rate is increased. Conclusion and analysis

Conclusion and analysis
The method for the experiment allowed for error to take place, but also had advantages. The results show some anomalies – these have come about because the samples were on the counter in front of the window and so the algal balls were subject to natural light coming in from the window as well as the artificial light. This error in the method meant that the results collected were neither accurate nor reliable as at the different intervals, the algal balls could have had varying light intensities and therefore the light...
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