The nicotine, using 3 umL, 6 umL, 9 umL,

The Effect of Nicotine on Drosophila Lifespan and Number of Offspring Claire McDonaldNinth Grade, Heathwood Hall Episcopal School3000 S Beltline Blvd, Columbia, SC 29201Abstract The purpose of this experiment is to determine the effect of nicotine on Drosophila lifespan and number of offspring. It was hypothesized that if the amount of nicotine solution is increased, then Drosophila will have a shorter lifespan and fewer offspring. Four different concentrations of nicotine were mixed by filling jars with 10 mL of water and using a micropipette to measure each amount of nicotine, using 3 umL, 6 umL, 9 umL, and 12 umL as the amounts. Each vial of food was made by mixing 10 mL of food with 8 mL of the nicotine solution. Five test tubes were assembled, each with a different concentration of nicotine, and four male Drosophila and four female Drosophila were placed in each test tube. The number of living Drosophila was recorded every day for 25 days. The data reveals that the flies that were not exposed to the nicotine food had much longer lifespans and they produced offspring. The flies that were exposed to nicotine had significantly shorter lifespans and did not produce any offspring. These results support the hypothesis that the Drosophila exposed to nicotine would have shorter lifespan and fewer offspring than the control group. Table of ContentsTitle Page………………………………………………………………………………………………………..……1Abstract……………………………………………………………………………………………………………….2Table of Contents………………………………………..………………………………………………………….3Introduction…………………………………………………………………………………………………………..4Materials and Methods ………………………………………………….…………………………………………6Results………………………………………………………………………………………………………………..8Conclusion…………………………………………………………………………………………………………..10Introduction As nicotine becomes a popular way to quit smoking, consumers may be unaware of the harmful effects. A recent study by the Indian Journal of Medical and Paediatric Oncology states that although nicotine is not listed as a carcinogen like tobacco, it does have many health risks. Prolonged exposure can lead to cardiovascular, respiratory, and gastrointestinal problems, reproductive health issues, and DNA mutation that leads to cancer (Aseem et al. 2015). Nicotine is also effectively used as pesticide, because “Nicotine, it turns out, is so toxic that it was one of the first chemicals used in agricultural insecticides” (PLoS Biol. 2004). Nicotine is the main ingredient in e-cigarettes, which are marketed as safe alternatives to tobacco products (NHS 2018), but a study by the National Institute on Drug Abuse states that “Most smokers use tobacco regularly because they are addicted to nicotine” (NIDA 2018). The reason for its addictiveness is its quick absorption into the bloodstream. When a nicotine product is smoked, it absorbs into the bloodstream in ten seconds, causing the brain to release adrenaline. The adrenaline causes a “buzz of pleasure”, which quickly disappears and makes the consumer want more (HHS 2018). Nicotine may be a safer alternative to tobacco; however, it does have many health ramifications, which this study intends to prove.Because Drosophila, or the common fruit fly, are used as model organisms for human reaction, the effects of nicotine shown in this study could inform nicotine users of the possible consequences. For over a decade, scientists have been using Drosophila as a model organism to study human reaction. They have been used to study human genetics, neurobiology, autism, cleft palate, and even alcoholism, as they share 60% of genes that are changed by disease with humans (Elgin 2018). They are better model organisms than others, such as the zebrafish, because of how easy they are to care for, their short generation time, and their amount of offspring (Eberl 2014). On average, Drosophila can live 40-50 days, with a reproductive cycle of 8-14 days (YourGenome 2015), making them ideal for research. The history of Drosophila as model organisms started in 1908, when Thomas Morgan Hunt began to study its embryology, or the study of development from fertilisation to formation of an embryo (YourGenome 2016). He discovered the chromosomal theory of inheritance, which states that “inheritance patterns may be generally explained by assuming that genes are located in specific sites on chromosomes” (Lefers 2004). This theory was the reason white eyed flies were appearing when he only had red eyed flies. He published his theory, and that was the beginning of the use of fruit flies in experiments. Now, the fruit fly is one of the most understood organisms in the world (YourGenome 2016).The purpose of this experiment is to determine the effect of nicotine on Drosophila lifespan and number of offspring. The hypothesis of this experiment is that if Drosophila are exposed to nicotine, then they will have shorter lifespans and breed fewer offspring. The null hypothesis is that if Drosophila are exposed to nicotine, there will be no effect on the lifespan and number of offspring. The results of this experiment will show the harmful effects of nicotine and reveal that although nicotine and e-cigarettes are marketed as a safe way to quit smoking, they do have ramifications.MaterialsFive Vials of Wild-Type Drosophila, 30 Flies in Each Vial (Carolina Biological Supply Company)10g of Nicotine (Flinn Scientific)Drosophila Vials (Heathwood Hall Science Lab)Micropipette 1-10 umL (Heathwood Hall Science Lab)5 Glass Vials (Heathwood Hall Science Lab)Drosophila Food (Heathwood Hall Science Lab)Label Maker (Heathwood Hall Science Lab)FlyNap Drosophila Anesthesia (Heathwood Hall Science Lab)Microscope (Heathwood Hall Science Lab)Gloves and Lab Coat (Heathwood Hall Science Lab) Methods Title of the ExperimentThe Effect of Nicotine on Drosophila Lifespan and Number of Offspring HypothesisIf Drosophila are exposed to nicotine, then they will have shorter lifespans and breed fewer offspring. Independent VariableExposure to nicotine Levels of Independent Variable0 umL3 umL6 umL9 umL12 umLNumber of Repeated Trials1 vial, 10 flies1 vial, 10 flies1 vial, 10 flies 1 vial, 10 flies1 vial, 10 fliesDependent VariableThe effect of nicotine on lifespan of adults and number of offspring produced Constants/ Controlled Factors (List at least 5 )Temperature, amount of food, size of container, length of experiment, number of fliesControl GroupGroup not exposed to nicotine The vials of Drosophila and the nicotine were ordered from Carolina Biological Supply Company and Flinn Scientific. Each vial was anesthetized using FlyNap Anesthesia. Using a microscope, each vial of Drosophila was separated into males and females by identifying black bristles on the males’ legs. The males and females were placed into separate vials and stored at room temperature. Nicotine solutions were made by using a 1-10 umL micropipette and measuring each amount of nicotine, then mixing each amount with 10 mL of water. Labels were made for each jar of water. Five batches of Drosophila food were made by mixing 8 mL of Drosophila food flakes with 10 mL of each nicotine solution to make a batch of food for each concentration. Each batch of food was put into a new vial. Each vial of Drosophila was anesthetized again and four males and four females were placed in each new vial. A control group was made with no concentration of nicotine in the food. Labels were made for each vial. The vials were stored at room temperature and the number of living flies was counted every day for 25 days. The results were analyzed using the Anova test. Since nicotine and anesthetic are hazardous materials, gloves and a lab coat were worn. ResultsTable One: Anova Single Factor TestTable Two: Descriptive StatisticsTable Three: Descriptive Statistics ContinuedFigure One shows the number of living flies in each vial over 25 days. Figure Two shows the average number of flies alive in each vial over 25 days. Table One shows the results of the Anova single test. Table Two and Three show the descriptive statistics of the data. Figure One supports the hypothesis because it shows that all of the flies exposed to nicotine died much faster and had no offspring while the control group lived longer and had more offspring. Figure Two supports the hypothesis because the graph shows that the control group had a larger number of average living flies than the exposed groups, which means that the exposed groups died faster. Table One supports the hypothesis because the f value is larger than the f-crit value, which means the data is statistically significant. Tables Two and Three show the mean, median, mode, and standard deviation, which show the average number of flies in each vial, the middle number of flies, the most frequent number of flies, and the deviation for the whole group. These numbers are a good visual to represent the findings that the control group gained more flies and the exposed groups lost flies. The data rejects the null hypothesis, which states that if Drosophila are exposed to nicotine, there will be no effect on the lifespan and number of offspringConclusion The purpose of this experiment is to determine the effect of nicotine on Drosophila lifespan and number of offspring. The results show that the Drosophila exposed to nicotine had much shorter lifespans and fewer offspring compared to the control group. These findings support the hypothesis, which states that if Drosophila are exposed to nicotine, then they will have shorter lifespans and breed fewer offspring. The null hypothesis was rejected by the data. This study proves the results of the Indian Journal of Medical and Paediatric Oncology are correct, as they say that nicotine is harmful and should be regulated (Aseem et al. 2015). Some discrepancies in this study could be that only one trial was run, and some days may not have a completely accurate count of the number of living flies. The limitations of this study were the number of trials that were able to be run, and the amount of nicotine that could be used. In further study, it would be recommended that five sets of each concentration be used, and more Drosophila were put in each vial. Acknowledgments The researcher would like to thank Mrs. Norman, the science research teacher, for her guidance and support. The researcher would also like to thank Mr. Morris, the biology teacher, for his assistance. The researcher would like to thank Heathwood Hall Episcopal School and the Science Club for funding this project.Works CitedVelazquez-Ulloa NA. 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