Effects of Light Color on the Rate of Photosynthesis - Lab Report Example

Lab Report: Effects of Light Color on Rate of Photosynthesis Effects of Light Color on the Rate of Photosynthesis Aim of experiment: The aim of the experiment was to measure the effect of light colors on the photosynthesis of various trials of leaflets using NaHCO3. Introduction Different light colors affect the rate of photosynthesis. The rate of photosynthesis is largely dependent on wavelength of light, since the different lights have different amount energy, which is used in light stage of photosynthesis. There is a significance difference between the rate of photosynthesis and the kind of light that the leaf was exposed to, where the longest wavelength, has the least energy, thus lowest rate of photosynthesis. Using this knowledge, it is possible to conduct experiment aimed at identifying the effect of different lights on the rate of photosynthesis. I used five different colors in the experiment. According to Timmermans, (2010) different colors of light have a significant effect on growth of plants, where the amount of energy obtained is different. However, it depends on other conditions, such as temperature, light intensity among others. In this experiment, the researcher has four variables in place. They include independent variables (photosynthesis rate), dependent (effect of wavelength) and factors that are in control and those that were not in control. Control favors included number of leaflets, volume of NaHCO3, concentration of NaHCO3, size of disc used and power of the light that was used. On the other hand, uncontrolled factors were the room temperature that the experiment was carried in. The Hedera Helix discs (leaflets) in our experiment responded differently to different colors of light. Hypothesis of the Research The hypothesis of the study is that the rate of photosynthesis varies in different colors of light. The blue color was expected to show the highest rate and yellow color the least effect to the rate of photosynthesis. Research question To what extent does the light wavelength affects the rate of photosynthesis of the Hedera Helix discs (leaflets)? Material and procedures Materials The requirements for carrying out this experiment successfully include a syringe and beaker/containers. Others incldued leaves (the Hedera Helix discs (leaflets)), holes cutter, NaHCO3 and source of light (colored light bulb). Procedure I set up the five sources of colored light in an enclosed system and allowed it to warm up so as to attain equilibrium. I left the Hedera Helix Plant exposed to different light colors for 1.5 hours (90 minutes) using an analog-digital clocks to record the time elapses. This ensured that all the leaves were exposed to light equally. Using the prepared leaves, I prepared the NaHCO3 solution from 0.60g of sodium bicarbonate by diluting it with 300ml of distilled water in a 500ml beaker and added I added one drop of soap. I stirred the mixture gently ensuring that it does not form froth. First I cut small holes into the leaves to obtain numerous leaf particulars from each leaf that was exposed to different light colors. AS I cut the holes, I ensured that that leaves remained exposed to the light. I used a hole cutter to cut equal sizes of leaflets. I placed the Hedera Helix leaflets into the syringe with 1 ml of sodium bicarbonate solutions and inserted some pressure in the syringe. In order to create the pressure in the syringe, I placed my thumb finger over the opening of the syringe and pulled the handle back. This action must have exerted some pressure onto my thumb, if it did not, I knew that the seal was not tight. I inverted the syringe 4-5 times to ensure that the leaflets mixes with the solution. When the leaflets sinks I knew that the leaflets had absorbed the NaHCO3 solution. I poured the syringe content in 500 ml beakers which contained the remaining of my NaHCO3 solution, and made sure that there was no leaflets stuck on the side of the syringe. Finally, I placed the beaker under respected light source and started my digital timer. After that, I repeated the four other times for different measurement of different colors (Timmermans, 2010). I recorded time in which each leaf took to flow in a table. I swirled the solution to make sure that the leaflets also do not stick at the bottom of the beaker. Results The result that I recorded from the experiment was as tabulated below. Number of leaflet discs flowing Time (Minutes) ( Red Green White Blue Yellow 1 2 3 1 3 0 2 2 3 1 3 0 3 2 3 1 3 0 4 2 3 1 3 0 5 2 3 1 3 0 6 2 3 1 3 0 7 2 3 1 3 0 8 2 3 1 3 0 9 2 3 1 3 0 10 2 3 1 3 0 11 2 3 1 3 0 12 2 3 1 3 0 13 2 3 1 3 0 14 2 3 1 3 0 15 2 3 1 3 0 16 2 3 1 3 0 17 2 3 1 3 1 18 2 3 1 3 1 19 2 3 1 3 1 20 2 3 1 3 1 21 2 3 1 3 1 22 2 3 1 3 0 23 2 3 1 3 0 24 2 3 1 3 0 25 2 3 1 3 0 26 2 3 1 3 0 27 2 3 1 3 0 28 2 3 1 3 0 29 2 3 1 3 0 30 2 3 1 3 0 I used the tabulated data to come up with graphs that show the relationship between number of leaflets discs flowing and time. The graphs are as follows. Graph 1: Red color Graph 2: green color Graph 3: white color Graph 4: blue color Graph 4: yellow color The above figures show that blue and green color had the greatest effect on the rate of photosynthesis, where yellow had the least effect. Discussion From the graphs above, I noticed that the pattern is mostly rapid and constant in all aspects of the table. In addition, I noticed that there is a slight change in the rate of photosynthesis of the mixture that is yellow colored light area. The yellow color light took long time in this experiment in flowing and sinking, in contrast other colors did not have any significant change. These results show that there is no effect of colors light on the rate of photosynthesis. The results contradict my hypothesis that the rate of photosynthesis varies in different colors of light. On the other hand, it answered the research question in the experiment. Conclusion In conclusion, the results obtained were not as expected. The expected result was as per the hypothesis that different light color will affect the rate of theory. In my experiment, the effect was so weak that only yellow color area affected the rate for the little period by making one more leaflets flow for a couple of minutes and then sinking back. Some errors were encountered in the experiment, although the results obtained were reliable. In the future given a chance conduct the experiment again, I will correct these three errors and be more careful. Evaluation There were some errors that occur when conducting the experiment. Some of the errors could have occurred during focusing of light, in my experiment the light was not concentrated and directed to the plant. Instead, it covered a wide area so that there was no significant effect when compared to a focus scoped area of lighting. In order to correct this error I could have worked on a particular color for a given period which would improve the effect of the light on my experiment. The second error could have occurred when I used small sized leaflets that could have caused the lack of reaction. Besides, the results based on different sizes of the leaves could not be 100% identical. In order to overcome this drawback, I would have made fairly sized holes to obtain a medium sized leaflets which are nearly identical which would lead to a better outcome. The last but not least error could have occurred for my experiment was split into two days. This definitely made the state of the experiment’s trial change. In order to prevent the occurrence of errors, I would have done all the requirements in one day so to be as precise and accurate as possible. References King, T., Reiss, M. J., & Roberts, M. (2001). Practical advanced biology. Cheltenham: N. Thornes. Timmermans, M. (2010). Plant development. San Diego, Calif.: Academic Press. Read More