Variegatus Lab
Introduction: The question investigated in this lab was which drugs have the greatest and least affect on the pulse of the Lumbriculus variegates. Ethanol will cause the worms to become inactive, caffeine will cause the worms to become overactive, and nicotine will cause the worms to become more active. Lumbriculus variegatus is also known as black worm. This small species of worms currently lives in North America and Europe within marshes and ponds. They survive by eating microorganisms and organic, decaying material. This organism of worms makes a good model because they are able to regenerate if their head or tail is removed within two or three weeks. Under a microscope their skin is transparent and their pulsation rates are easy to count.
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Ethanol was given at 0.1mM and 1.0mM. The pulse rate difference was 10.31. Caffeine was given at 0.1mM and 5mM. The pulse rate difference was 1.7241. Since the worms were small and weighed little, they absorbed the drugs at a faster rate. Within 5 minutes the drugs had affected their original heart rate. The worm’s size and the worm’s heart rate work together. This experiment is valid because the worms at first we’re more active and after the drug was administered they became more still. With a higher concentration of alcohol the worms’ ends began to curl while their bodies stayed straight. For the most part, their pulsation rates decreased because alcohol is a depressant. Alcohol causes the organisms to feel sluggish and if a higher dosage was administered to the worms neurological damage could have occurred. The findings are reliable because those that also used alcohol with the worms conducted similar findings. With a smaller dose of ethanol, the change in pulse rates from initial heart rate to final heart rate was more in the negatives. Meanwhile, caffeine is an excitatory drug and causes organisms to experience bursts of energy. Caffeine is an antagonist, which means that it occupies receptors without activating them. It caused the worms to curl up and stretch, as their pulses increased. Then nicotine caused the worms to become more
Ethanol was given at 0.1mM and 1.0mM. The pulse rate difference was 10.31. Caffeine was given at 0.1mM and 5mM. The pulse rate difference was 1.7241. Since the worms were small and weighed little, they absorbed the drugs at a faster rate. Within 5 minutes the drugs had affected their original heart rate. The worm’s size and the worm’s heart rate work together. This experiment is valid because the worms at first we’re more active and after the drug was administered they became more still. With a higher concentration of alcohol the worms’ ends began to curl while their bodies stayed straight. For the most part, their pulsation rates decreased because alcohol is a depressant. Alcohol causes the organisms to feel sluggish and if a higher dosage was administered to the worms neurological damage could have occurred. The findings are reliable because those that also used alcohol with the worms conducted similar findings. With a smaller dose of ethanol, the change in pulse rates from initial heart rate to final heart rate was more in the negatives. Meanwhile, caffeine is an excitatory drug and causes organisms to experience bursts of energy. Caffeine is an antagonist, which means that it occupies receptors without activating them. It caused the worms to curl up and stretch, as their pulses increased. Then nicotine caused the worms to become more