Testing the Effects of Radiation on Plants free essay sample

The purpose of this lab was to see if radiation has an effect on the cultivated radish seeds that we used. From the observed data that we collected, we were able to conclude that when seeds are exposed to radiation, it affects how they grow, if there is any growth at all. Introduction Radiation is an important environmental abiotic factor for plants, and one small section of the electromagnetic radiation spectrum, is called the Photosynthetically Active Radiation (PAR), provides the energy to drive the light reactions of photosynthesis. Such radiation damages biological tissues by detaching electrons from the atoms that make up organic molecules. The results include radiation poisoning, cancer, and elevated mutation rates. Scientists use ionizing radiation to increase gene mutation rates in experimental organisms such as plants. The treated plants are then grown under selected environmental conditions in order to enrich the population with that mutant. The probability of generating â€Å"improved† mutants is low, and is what was observed in this lab using radish seeds exposed to various levels of high-energy gamma radiation (50-mrad, 100-mrad, 150-mrad, control). We will write a custom essay sample on Testing the Effects of Radiation on Plants or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page In this lab, there were four questions observed: 1. Does exposure to high-energy electromagnetic radiation have a measurable effect on radish seed germination rates? 2. Does exposure to such radiation have a measurable effect on radish seedling growth? 3. If you can demonstrate any effect, is it dependent on the level of radiation exposure? 4. Do individuals in the population exhibit variations in their tolerance to radiation exposure? First Hypothesis: Ho: Seed germination has nothing to do with gamma radiation (50, 150, and 500) HA: Gamma radiation will have an effect on seed germination Second Hypothesis: Ho: Seedling growth will have nothing to do with gamma radiation levels HA: The gamma radiation levels will effect seedling growth differently, depending on the level. (50, 150, and 500) Materials and Methods Reference the Laboratory Exercises in Biology Chapter 17 Testing the Effects of Radiation on Plants pages 168 -169. Results Flaming Novas Plant Growth Table Control50 mrads150 mrads500 mrads Seeds: 09/185 cm NG 3. 9 cm2 cm Seeds: 09/2510. 5 cmNG6 cm6. 4 cm Seeds: 10/0213. 5 cmNG6 cm6. 7 cm Table 2: Test of Normality using the Kolmogorov-Smirnov test (N is greater than 50) Results are considered normal if p-value is greater than alpha level (0. 05). RadiationTest StatisticDfp-valueResult Control0. 060960. 20Significant 50 mRAD0. 107770. 028Not significant 150 mRAD0. 087890. 090Significant 500 mRAD0. 115840. 008Not significant Not all radiation levels were normal, so all data is considered not normal or non-parametric. Figure 1: Showing height of plants over three weeks of growth under radiation. Discussion For the first week of growth, the control (non-irridiated) was at a height of about 5 centimeters, second week about 10. 5 cm, and last week at final height of 13. 5 cm. The 50- mrad for all three weeks had no growth. The 150-mrad was at a height of about 3. 9 cm, and for week two and three stayed at 6 cm. The 500-mrad was at 2 cm for the first week, the second week was at 6. 4 cm and for the third week at 6. 7 cm. The control and radish seeds were all placed in a tray with one pellet of fertilizer and about the same amount of potting soil and was sprayed with water by the lab assistants on a daily basis. And once a week the same member from the Flaming Novas would measure the plants (myself). The control, which is the only one that is supposed to be radiation free grew the highest at 13. 5 cm; it was also the one that grew the most each week. The 50-mrad radish seed never experienced any growth. The 150-mrad radish seed shot up about 4 cm the first week and then the second and third week stayed at the same height. From these observations we can tell that there was a significant difference between the control and the radish seeds that were inflected with radiation. The ones that contained radiation either experienced no growth at all, experienced stunted growth, and were never as tall as the control. I reject both null hypothesizes, and fail to reject both alternative hypothesizes since the radiation did prove to have an effect on the radish seeds. Conclusion From the obtained data, we were able to fail to reject the alternate hypothesizes. Gamma radiation levels had effects on the radish seeds. We were able to determine these levels by comparing these results to the control which was just a radish seed that was never altered by any radiation for as far as we know.