Question

In $1953,$ S. L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include

• A. low temperature, volcanic storms, atmosphere rich in oxygen
• B. low temperature, volcanic storms, reducing atmosphere
• C. high temperature, volcanic storms, non-reducing atmosphere
• D. high temperature, volcanic storms, reducing atmosphere containing $CH_{4}andNH_{3}$ , etc.

Answer 1

Answer: (D)

Experimental proof of the theory of chemical evolution was given by Urey and Miller in 1953, who created primitive atmospheric conditions in a laboratory, by using electric discharge in a closed flask containing CH₄, H₂, NH₃ in 2: 1: 2 ratio and water vapour at 800⁰C. This mixture was provided with energy for interaction by 75000 volts sparks using electrodes. The gases were allowed to condense in a narrow tube and pass through a liquid flask.
He performed this experiment continuously, for a week and analyzed the composition of the liquid inside the apparatus. He found a large number of simple organic compounds including some amino acids such as alanine, glycine, and aspartic acid. Miller, thus, proved that organic compounds were the basis of life.