EVOLUTION
THE ORIGIN OF LIFE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The broth was contaminated by microorganisms found in the air when he transferred the broth to the clean flasks
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The scientist secretly introduced the microorganisms into the broth so that it would appear they were generated by the broth
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The heat killed the microorganisms but converted some of them into viruses that were then found to multiply in the cooled broth
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The cloudiness of the broth was not caused by microorganisms but was instead caused by oxidation
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Detailed explanation-1: -In 1745, John Needham briefly boiled broth, which contained both plant and animal matter. He believed this brief period of boiling would kill any microorganisms living in the broth.
Detailed explanation-2: -Louis Pasteur’s 1859 experiment is widely seen as having settled the question of spontaneous generation. He boiled a meat broth in a swan neck flask; the bend in the neck of the flask prevented falling particles from reaching the broth, while still allowing the free flow of air.
Detailed explanation-3: -The Greek philosopher Aristotle (384–322 BC) was one of the earliest recorded scholars to articulate the theory of spontaneous generation, the notion that life can arise from nonliving matter. Aristotle proposed that life arose from nonliving material if the material contained pneuma (“vital heat”).
Detailed explanation-4: -The prize was claimed in 1864 by Louis Pasteur, as he published the results of an experiment he did to disproved spontaneous generation in these microscopic organisms. Observation(s): From Needham’s and Spallanzani’s experiments, it was known that soup that was exposed to the air spoiled-bacteria grew in it.
Detailed explanation-5: -Figure: Antoni van Leeuwenhoek: A drawing of Antoni van Leeuwenhoek, one of the first scientists to use a microscope and identify microbes. Lazzaro Spallanzani (1729–1799) found that boiling broth would sterilize it and kill any microorganisms in it.