Summary
For thousands of years, humans believed in the existence of spontaneous generation. This idea states that life or living organisms can be spontaneously generated from non- living matter. But as we know today, this theory is not accurate. We now know that all cells must come from other cells (according to the cell theory). Because of the experiments that Louis Pasteur and Francesco Redi conducted, we know that spontaneous generation is not true.
Francesco Redi was able to disprove the idea that maggots arise from decaying meat. He designed a simple and controlled experiment, with the appearance of maggots being the dependent variable. He had two identical jars, both with a piece of meat in them. One was left open, while the other one had a cheese cloth on it (it allowed air to pass through, but not large objects- such as flies). Since air was provided in the two experiments, the meat decayed in both of them. But, only the jar left opened produced maggots, while the other jar had eggs on the top of the cheese cloth. The fact that maggots were not produced by the decaying meat itself (in the absence of egg laying flies) revealed that spontaneous generation does not happen.
Relevance to Class
This week, we have learned about various aspects of the cell theory. The cell theory states that cells are the units of structure in living organisms, that cells are the units of function in living organisms and that all cells arise from preexisting cells. The idea of spontaneous growth contradicts that notion that cells must arise from preexisting cells. Experiments like the one conducted by Francesco Redi have dis-proven the theory of spontaneous growth. Therefore Redi helped proved that life (or cells) must come from other living life.
Video Information
Date of Publication: September 18, 2012
Creator's Youtube username: PasteurBrewing
Is the dependent variable in this experiment seeing whether or not maggots came out of the meat or seeing what kind of cloth does not allow maggots to form in?
ReplyDeleteThe dependent variable would be whether or not maggots came out. The cloth acted as the independent variable- the variable that was changed.
ReplyDeleteIn the last slide of the video, there was a jar that was completely sealed. What was Redi trying to prove/disprove with this part of the experiment?
ReplyDeleteBefore Redi did this experiment, he had done one similar to it. He completely covered one container, and left the other container completely open. Although, he was soon criticized by saying that spontaneous generation needed air. So, he did an improved experiment with three tests (sealed, open, cloth). But, in this new test he kept the sealed container, to prove that spontaneous generation does not occur with either an air source or not. I found this on:
Deletehttp://faculty.fmcc.suny.edu/mcdarby/Molecules&CellsBook/02-Science.htm