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Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from plantphys.info for as long as that website is available. Images lacking photo credits are mine and, as long as you are engaged in non-profit educational missions, you have my permission to use my images and slides in your teaching. However, please notice that some of the images in these slides have an associated URL photo credit to provide you with the location of their original source within internet cyberspace. Those images may have separate copyright protection. If you are seeking permission for use of those images, you need to consult the original sources for such permission; they are NOT mine to give you permission.
Observation Question Hypothesis Prediction Experiment Analysis Decision RejectCannot Reject re-test from different perspective Scientific Method after many cycles without rejection Hypothesis becomes Theory revise
1. The “Bulb Absent” hypothesis was tested first because: A.It is likely someone stole the bulb. B.It is the correct step in the scientific method. C.Bulbs often disappear and reappear magically. D.The test of this hypothesis is easy, fast, and decisive.
2. Which would be the most conclusive observation during the experiment testing the “Power Is Out” hypothesis? A.All neighboring houses are dark. B.Some neighbor’s houses have light inside. C.Other lights in my house are out. D.Streetlights and Stoplights are out.
3. In testing the “Switch is Broken” hypothesis, why the multiple flips? A.Had to be 100% sure of results. B.Required to prove hypothesis. C.To exceed the number of trials needed to meet the chosen % allowed for statistical error. D.Number chosen randomly by the person.
Bulb In? Bulb Burned Out? Power On? Switch Broken? Wire Shorted? Plugged In? Paid Bill? Bulb loose? Scientific Method after many cycles without rejection Hypothesis becomes Theory Theory of Evolution Law of Conservation of Matter Law of Conservation of Energy An Alternative Lamp Theory?
Louis Pasteur: Testing The Question of Spontaneous Generation French Biochemist and Microbiologist Germ Theory of Disease Pasteurization of Food (60°C 30 min) Vaccinations against Rabies and Anthrax
Page 4 Figure 1.2 Cells arise spontaneously from nonliving materials. Cells are produced only when preexisting cells grow and divide. Do cells arise spontaneously or from other cells? Pasteur experiment with straight-necked flask: 1. Place nutrient broth in straight-necked flask. 2. Boil to sterilize the flask (killing any living cells that were in the broth). 3. Preexisting cells enter flask from air. No cells Cells Cells will appear in broth. Cells Cells arise from preexisting cells, not spontaneously from nonliving material. No cells Spontaneous generation hypothesis rejected Cells will not appear in broth. Cells will appear in broth. 1. Place nutrient broth in swan-necked flask. Cells Pasteur experiment with swan-necked flask: Cells No cells 2. Boil to sterilize the flask (killing any living cells that were in the broth). Condensation settles in neck 3. Preexisting cells from air are trapped in swan neck. Both hypotheses supported