Redi: Scientific Method and Heather Ramirez Page

1. State a possible hypothesis for Redis experiment. -Hypothesis for Redis experiment is that maggots come from larva of go and that the internalitys only serve as food for the developing insects. 2. Which of the three jounces in Redis experiment would be considered the control and why? -The totter that was left uncovered in the experiment would be considered the control because this jar represented the meat as it would normally be found with the maggots attached. 3. Give a brief exposition of Redis experimental procedure. Redi preformed an experiment to judge where maggots came from. He took three jars and put a piece of meat in each jar. Jar 1 was left uncovered, jar 2 was covered with benefit (gauze), and jar 3 was sealed from the outside. In jar 1, maggots were found on the meat and there were flies warm around that had laid eggs on the meat. Jar 2 was found to have maggots on the netting of the jar, because the flies had begun to lay their eggs. Jar 3 had not developed an y maggots on the meat, which proved that active things are not spontaneously generated.Heather Ramirez Page 2 4. Why would the experiments run by Redi, Spallanzani, and Pasteur be considered as a possible basis for a theory? -Redi, Spallanzani, and Pasteur all utilise similar experiments to prove that living things are not spontaneously generated and through their experiments they were able to can their hypothesis with scientific logical thinking. The experiments preformed were considered well-grounded because of the reproducible outcome in each study. 5-6. What were the possible conclusions reached from Spallanzanis experiment?Why were his conclusions not true? -After boiling the breeds no bacteria was present. Although his experiment was successful, his conclusions were not accepted because he had deprived the sealed flasks of form by melting their glass necks and it was thought that air was necessary for spontaneous generation to occur. The experiment was overly contradic ting because, if the flasks neck became cracked the broth would thusly obtain a rapid growth of microorganisms. 7.Why would Aristotles thoughts on spontaneous generation be considered nonscientific reasoning? -Aristotle believed that living things arose and always had arisen from lifeless matter. This would be considered nonscientific reasoning because these were just his thoughts and beliefs, not something that was scientifically tested. For something to be classified as scientific reasoning it would require an demonstrable scientific research method, such as an Heather Ramirez Page 3 xperiment to first predict and then test the hypothesis to ultimately come to a conclusion based on the results from the experiment. 8. How did Pasteur modify Spallanzanis experiment in order to provide further experimentation on spontaneous generation? -Pasteur used swan-necked flasks which allowed air into the flasks but the route was so convoluted that any particles couching in from the air woul d make up out in the folds of the glass before reaching the broth. His flasks were open to the air but did not support bacterial growth like Spallanzanis flasks did.This method had rejected the possibility of spontaneous generation because the broth in the swan-necked flasks remained clear which concluded the previous tests done by Spallazani and Needham were not accurate. The normal flasks allowed bacteria to drift into the broth causing cloudy bacterial soups and had thickened the rich nutrients due to the bacteria multiplying. 9-10. In coiffe for experimental results to be accepted, the results must be reproducible. Why did Tyndall have problems reproducing Pasteurs work and how did he sack up the problem? Pasteur and opposites scientist were using different types of broths. (Pasteur only used broths made with sugar or yeast extract, and the other scientist were using broths made from hay) As a result, Tyndall found that these different types of broths required different boil ing generation to be sterilized. He found that certain microorganisms can exist in heat- Heather Ramirez Page 4 resistant forms, which are called endospores. Once this conflicting data was brought to light Tyndall was able to reproduce Pasteurs experiment and prove him to be correct.