Effect of caffeine, nicotine, alcohol, epinephrine on Daphnia

03 - 31 - 2006 RESULTS: In this experiment the effect of different hormones on heart rate of _Daphnia_ was examined. It was investigated which substances act as stimulants and which substances act as depressant. Initially, _Daphnia_ was placed on depression slide under the microscope and the average heart rate was determined. Subsequently, _Daphnia_ was treated with different type of hormone and the effect on Daphnia heart rate was observed. It was investigated which substances act as stimulants and which substances act as depressant. Daphnia was treated with aged water, caffeine, ethyl alcohol, nicotine, and epinephrine, and their effect on heart rate of Daphnia was observed. The results are posted on table 1: Table 1: Average heart†¦show more content†¦Heart rate of daphnia fell from an average of 274.455+/-26 beats per minutes to an average 246.868+/-71 heart beats per minute. After performing Mann-Whitney U statistical test, this difference in heart rate was found to be statistically not significant. In last procedure, the effect of epinephrine on Daphnia heart rate was observed. The result is posted on figure 5: Figure 5: Effect of Epinephrine on average heart rate of Daphnia From figure 5 it can be seen that before the addition of epinephrine, Daphnia had an average heart rate of 277.663+/-18 heart beats per minutes. However, when epinephrine was added, the average heart rate was decreased to 291.467+/-57 heart beats per minute. However, after performing Mann-Whitney U test, it was found that after the addition of epinephrine, no significant difference was observed in Daphnias heart beats. Mann-Whitney U statistical testing was performed to see if the result obtained for the difference in heart rate of Daphnia before and after the addition of stimulant was significant. The statistical test for the difference in heart rate of daphnia observed after the addition of aged water is shown on table 2: Table 2: Mann-Whitney U statistical testing for the difference in average heart rate of Daphnia before and after the addition of aged water: B B A A B B A A A A B B A B B A 194 200.67 204 204.68 259 260 264 264.67 273.3 277.2 278 283.4 285Show MoreRelatedDaphnia Lab Essay1153 Words   |  5 PagesDaphnia and Additives Lab Purpose The purpose of this lab is to test what effect of Nicotine, Acetylcholine, Epinephrine, Caffeine, and Ethanol on an organism’s heart rate. Materials * Microscope * Eye dropper * Pipet * Cotton balls * Depression slide * Beakers * Daphnia * Water * Five additives: Nicotine, Acetylcholine, Epinephrine, Caffeine, Ethanol Procedure 1. Put on safety goggles. 2. Catch a living Daphnia. 3. Transfer to a depression