Name the scientist who had used the set-up shown below. Write the purpose of ‘a’ in the set-up and the conclusion the scientist arrived at.

The scientist who has used the set-up shown below was S.L. Miller.

The purpose of 'a' in the set up is to provide electric discharge as a substitute of thundering.

He created conditions of primitive Earth in a laboratory scale. He created electric discharge in a closed flask containing methane , hydrogen , ammonia and water vapour at high temperature. He observed formation of amino acids. And later on with other discoveries, other biomolecules were seen to be formed too. The conclusion that he came at from the experiment is about the chemical evolution of life.