Which of the following did Stanley Miller place in his experimental system to show that organic molecules could have arisen from inorganic molecules on the primitive earth?
A. Primitive gases
B. Microspheres
C. Purines and pyrimidines
D. All of these

Hint:-Before we directly come to the answer of this question first of all we need to understand that, Organic life has evolved from inorganic molecules but this statement is very different from saying that life has evolved from non-living things.

Complete step-by-step solution:-There have been many experiments and theories that were given in response to evolution by numerous scientists out of which Stanley Miller has a very dominant standing.
Chemogeny means chemical evolution and the experiments of Stanley Miller and Harold Urey favored the evidence of chemical evolution.
They performed the experiment in 1953 and created the similar conditions at a laboratory scale which would have been at the time of genesis, like thunder, the temperature and the reducing atmosphere.
 The reducing atmosphere means at the time when life was evolving, oxygen was not present in its free state; rather it was bound in water molecules so the atmosphere was reducing at that time.
Miller took Methane, Ammonia and hydrogen along with the water vapors at 800 degree Celsius, in his very sophisticated self-made apparatus. He created electric discharge by using two tungsten electrodes as a source of energy and observed the formation of simple amino acids like glycine, alanine, aspartic acid and even purines and pyrimidines along with other sugar derivatives.


Thus, the correct option is (a) Primitive gases.



Note:-
- The main aim of his experiment was to prove that even the simple inorganic molecules when treated under specific state of condition can give race to the complex organic molecules
- There were many scientists who tried to synthesize artificial living molecules like protobionts and coacervates. Similarly, Sidney Fox synthesized some microscopic protein surrounded by the lipid coat called microspores.