Independent Variable- The T oxin Fluoride

1. Effects of Fluoride on the Pulse Rate of A California BlackwormBy Dylan Bader and Mariah Elsenheimer Results- After testing the pulse rate of the California Blackworms while exposed to the toxin fluoride we found that with one ml of fluoride the average pulse rate was lower than spring water.(mean value 10.1)We also found that with 0.75 ml of fluoride that the pulse rate was lower than spring water but higher than 1 ml of spring water(11.4). Independent Variable- The Toxin Fluoride Dependent Variable- Pulse rate of the California Blackworm Control Group-California Blackworm in spring water Constants-Spring water as base for the solutions, The same microscope, Same time under microscope, same length blackworms, Constantly using welled slides, same people counting the pulse rate of the California blackworm. Introduction- The California Blackworm which is otherwise known as LumbriculusVariegatus is a freshwater organism that has transparent skin and a closed circulatory system which is beneficial while trying to read the pulse rate of the Blackworm. We chose to test the pulse rate of the California Blackworm while exposed to fluoride. Fluoride is only mildly toxic but we are hoping for some type of a result that supports our hypothesis. During this lab we will determine weather Fluoride is a stimulant or a depressant or has no effect on a blackworm at all. We predict that the California Blackworm will have a overall lower pulse rate when exposed to the toxin fluoride if you compared it to spring water. Conclusion- After testing our various fluoride solutions on the California Blackworm we have determined that our data does agree with our hypothesis. Our hypothesis stated that the pulse rate of the California Blackworm would go down when it was exposed to fluoride and this is exactly what happened. In the future I would start off with a lower dosage of fluoride because our solution with the 1ml of fluoride killed all of the blackworms. The solution with .75ml of fluoride was just perfect because it had an effect on the blackworm but not so much that the worm died. Procedure- First purchase the blackworms and keep them in spring water. Wash it out every couple of days to remove waste. Next, create your stock solutions using 1ml and .75 ml combined with spring water. Then you can count the pulse rate per minute by looking at ten worms from each solution. Remember your constants when doing this though. Before you do anything though remember to use the proper safety precautions. References- National Research Council of the National Academies of Science. 3/2006 . National Research Council (2006) . URL-http://www.fluoridealert.org/researchers/nrc/ Dwyer, Marge 7/25/2012 Impact of Fluoride on Neurological Development in Children. URL-http://www.hsph.harvard.edu/news/features/fluoride-childrens-health-grandjean-choi/