Question

How primitive life might have originated on earth was experimentally shown by
A. Urey and Miller
B. Watson and Crick
C. Oparin and Haldane
D. Hershey and Chase

Answer 1

Origin of life is formally called Abiogenesis. As per the studies life began on earth about 3 million years ago. It is based on oldest rocks with fossil evidence of life on earth. A lot of scientists performed experiments and proposed hypotheses of how life might have originated on earth.

Complete answer:
Life began on earth about 3 million years ago and it is determined by the presence of oldest rocks with fossil evidence. The earliest fossil evidence of life on earth were stromatolites.
Oparin and Haldane were the first one to draw hypotheses. They suggested that life arose slowly from inorganic molecules, like amino acids forming and combining to form complex polymers. Miller and Urey were the first one to experiment it and provided the evidence of how life might have originated on earth. Let’s understand their experiment in detail.
In 1953, the Oparin-Haldane hypothesis was tested by Urey and Miller. The components used in their experiment included

Mixture of gases- ammonia, hydrogen, and methane in a flask
Boiling water
Condenser
Tungsten electrodes for high frequency spark
Glass flask connected in a loop with one flask half filled with water and another containing pair of electrodes
In this experiment, steam from boiling water mixes with the gases in the apparatus which is passed into the section containing the electrodes. Then the steam in mixture gases is cooled with the help of the condenser and flows back to the water flask. The fluid formed was analyzed and the mixture consisted of amino acids as suggested by Oparin and Haldane in their hypothesis along with purines and pyrimidines.

Thus, the correct answer to this question is option ‘A’- Urey and Miller.

Note: According to the Oparin-Haldane hypothesis life on earth evolved in the oceans during the time when the atmosphere was reducing, forces such as lightning and electrical discharge rained into the ocean. Haldane suggested that sea served as a ‘primordial soup’ filled with organic monomers and polymers.