Nicotine Effect on Lumbriculus variegatus

1. Conclusion: Our hypothesis that the pulse rates would be lower in the .1mM solution than the .05mM and distilled water, was proven correct by our data. The pulse rates of the .1mM solution were generally lower than the other trials, with the exception of one worm who had a pulse of 40. We believe that worm took to the solution differently because it might have been a worm of younger age. Beginning with the .05mM solution, the trial took around 25 minutes to complete, and the .1mM around 27 minutes. If we did the experiment again, we would try to make the time the worms spend in the solution lower. Introduction: For our experiment, we are testing the effect of the toxin, nicotine on Lumbriculusvariegatuspulse rates. Lumbriculusvariegatusare good worms to test with because they are transparent and hemoglobin like blood cells. Nicotine provides a depressant and stimulant effect on organisms. When we had previously experimented the affect of a depressant on Black Worms, we concluded the pulse rates to be lower than those in distilled water. Our hypothesis in this experiment is: If we put Black Worms into .1mM nicotine solution, than the worm’s pulse rates will be lower than the rates of the worms in the .05mM nicotine solution and distilled water cups. Nicotine Effect on Lumbriculusvariegatus By: JulissaCurcie and Shannan Wells Procedure:Label three cups, (distilled water, .05mM solution, .1mM solution) Place 10 worms in the distilled and .05mM cups. 10 minutes later, put 10 worms into the .1mM solution. This staggers the worms in the concentration. Then label three more cups all with distilled water, for recovery purposes. Acquire 1 well slide and cover slip. Start with the .05mM solution trials. Place the first worm under the microscope on 10x for 30 seconds, counting the pulse in the mid-section, then double. Record data. Place that worm into the matching distilled recovery cup and repeat for the rest of the worms. Do the same procedure for the worms in the .1mM solution, then the distilled water, still putting each worm into the designated recovery container. When all completed, return the solution recovery worms into the recovery container and the distilled water worms back in their original container. Averages of Pulse Rates: Distilled water: 232 .1mM solution: 164 .05mM solution: 198 References: http://www.ableweb.org/volumes/vol-27/07_Bohrer.pdf Ind. Variable: nicotine solution Dep. Variable: pulse rates Control Group: worms in distilled water Constants: amount of light, water temp, midsection for counting pulse Observations: The worms in the .05mM solution were not moving much at all and were not gathering together. Half way through the .1mM solution trial, we noticed some worms appeared to be bleeding and we began wondering if some were dead because it was extremely difficult to find their pulse. However, a few worm pulses would speed up throughout the 30 second counting time span. Materials: microscope, well slide, cover slip, 30 worms, six container cups, distilled water, .05 solution, .1 solution.