The Effects of a Depressant on the Pulse Rate of Lumbirculus Variegates Intro The Black Worm is used for scientific testing by professors all over the world. With its closed circulatory system and simplistic design it is easy to count the pulses. The transparent skin makes it incredibly easy to count the contractions caused by the pulse. In this experiment we tested the effect on the pulse rate if we put the worms in a depressant solution. Hypothesis: If we put the Black Worm in a depressant solution, then its pulse rate will decrease compared to the pulse rate in the spring water. Independent Variable: Depressant water Dependent Variable: The pulse rate Control Group: the group with Spring water Constants: Slide, Microscope, timer, time of day. Materials  Black worms  Microscope  Spring water  Depressant,  Timer,  Plastic Pipette  Containers to hold the worms in  Recovery dish  Slides with well cutting. Method To test the pulse rate of the black worm you would need to get 15 black worms. Once you get the black worms you would place them into a container with spring water, a depressant or a stimulant. Then you would get a black worm with a pipette and place it onto a slide. After you place it on the slide you would put the slide onto the base of the microscope. You would adjust the knob on the microscope and focus on the specimen. After you focus in on the specimen record how many pulse rates the black worm gets per minute. You would run the trial a total of 15 times. After you run the trial find the average of all the pulse rates of the black worms. Our hypothesis was “If black worms were placed in a depressant, then there pulse rate per minute would decrease compared to the spring water”. After fifteen trials and after conducting the lab we came to the conclusion that the depressant decreased the pulse rate compared to when they were placed in spring water. The average pulse rate of the black worm in the depressant out of fifteen trials was While the average pulse rate of black worms in spring water was 19.8, out of five trials. If we could go back and could go back and redo the experiment, we would do an equal amount of trials for each. References Bohrer, K.E Effects of drugs on pulsation rate of Lumbriculus variegatus (blackworms).Pages ,in Tested Studies for Laboratory Teaching, Volume 27 (M.A. O'Donnell, Editor). Proceedings of the 27th Workshop/Conference of the Association for Biology Laboratory Education (ABLE), 383 pages. Drewes, CD A toxicology primer for student inquiry: Biological Smoke Detectors. The Kansas School Naturalist, Emporia State University, 50(1): Results Throughout the experiment we found that the pulse rate did decrease. Average pulse rate of the worm in spring water was 19.8 while as the average pulse rate of the worm in the depressant water was Conclusion Andrew Hollenbeck Ryan Collins Slide Tape Cover Well cut Black worm