Aim- To see how the wavelength of visible light affects the rate of growth of aquatic plants Different wavelengths of light will effect to rate of photosynthesis. I will test this by exposing the pondweed to different wavelengths of light to see how it reacts.
I will do this by passing white light through a filter. The filter will remove all unwanted wavelengths of light leaving the plant exposed to only the desired wavelength of light. I will use three different wavelengths of light 750nm (red), 650nm (green), and 550nm (violet). I will keep the distance from the light source to the pant the same for each experiment. There are many factors will need to take into account but the most important of theses in light intensity. I expect that the most successful will be either blue red or white. Green I think will be the least successful. I will measure the amount of gas produced in 1 minute. I will repeat this 3 times for each wavelength of light.
I have done a shot preliminary test and I will need to make some modifications to my method. Because of there is such a small amount of gas produced I have chosen to count the number of bubbles rather than the amount of gas. This should give me more accurate results. Have also chosen to leave the pondweed in the dark for a few minutes before starting my experiment. Because of the nature of photosynthesis the plant will still be photosynthesising the original light into gas at the same time it is exposed to the chosen wavelength of light this will give me anomalous results. So help stop anomalies such as this I will leave the pant in the dark until it has stopped photosynthesising.
This picture is of the results off an experiment similar to my own. This secondary source is a graph of the absorption rate of photosynthesis. From the graph I can tell that chlorophyll will absorb the wavelengths 700-775nm and 500-350nm that is essentially red and violet light. And the wavelength it...