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Evolution — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYEvolution3 Marks
Question
Explain the experiment done by Miller regarding the origin and development of life. ###Make a clearly labeled picture of Stanley Miller's experiment. ###How the experiment done by Miller proved that the initial development of life happened from preexisting lifeless organic molecules.
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Answer

American scientist Stanley Miller under the guidance of teacher Harold C. Urey provided the first experimental evidence in the support of chemical evolution theory of Oparin. He filled a glass chamber of 5-litre with a gaseous mixture of methane, ammonia and hydrogen gases in the proportion of 2:1:2. A tube carrying water vapour was also connected to the chamber to provide a continuous supply of water vapour to the larger flask. To tungston electrodes connected to an electric were fitted to the larger flask to provide energy of electric discharge stimulating the effect of lightning of the primitive atmosphere that is why Millers apparatus is also called Spark discharge operator. On the other side, the large flask was connected to a small U-tube by means of a straight tube passing through a condenser. When the experiment had continue for about a week, the gases formed get condensed as dark red liquid in the U-tube. Chemical analysis of this mixture reported the presence of simple organic compound like amino acids such as glycine, alaline and simple organic acids like ribose sugar, purines, pyrimidines etc.
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