OBJECTIVE LIFE SCIENCE
EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Used two containers of rotten meat, one covered and one uncovered and the appearance of flies
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Boiled chicken broth, one left in an open flask and the other left in a sealed flask.
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Boiled chicken broth in a goose necked flask that stayed there for a year with no signs of microorganisms until the flask was broken.
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None of the above
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Detailed explanation-1: -Louis Pasteur is credited with conclusively disproving the theory of spontaneous generation with his famous swan-neck flask experiment. He subsequently proposed that “life only comes from life.”
Detailed explanation-2: -By sterilizing cultures and keeping them isolated from the open air, Pasteur found that contamination of the media only occurred upon exposure to the outside environment, showing that some element was needed to give rise to life. In other words, life does not arise spontaneously.
Detailed explanation-3: -He heated an infusion sealed in a vessel with a S-shaped or “Swan neck", let it cool, and then broke of the tip of the vessel. This allowed fresh air to enter, but any particulate matter was trapped in the bend of the neck. The culture did not putrefy, even though it had access to air.
Detailed explanation-4: -The broth in the broken flasks quickly became cloudy-a sign that it teemed with microbial life. However, the broth in the unbroken flasks remained clear. Without the introduction of dust-on which microbes can travel-no life arose. Pasteur thus refuted the notion of spontaneous generation.
Detailed explanation-5: -Pasteur’s experiment consisted of boiled broth in flasks with S-shaped necks. The broth was boiled after being poured into the flasks to destroy any living microorganisms that may have been present in the broth. The S-shaped necks prevented microorganisms from entering and contaminating the broth after boiling.