Question

Miller and Urey experiment is support of the Oparin Haldane hypothesis of chemical evolution containing which of the following gases?
I. Hydrogen gas
II. Oxygen gas
III. Methane
IV. Ammonia

A. I and II only
B. II only
C. I,III and IV
D. II and IV

Answer 1

Hint: Miller and Urey experiment simulated early earth conditions in a lab and tested the origin of life under those conditions. The experiment suggested that life arose from inorganic molecules with “building blocks” like amino acids.

Complete Answer:
Oparin -Haldane hypothesis stated that the inorganic materials spontaneously create organic molecules. Oparin suggested that a primordial soup of organic molecules might have formed under oxygen less conditions of primitive earth and in presence of sunlight. The combination of these molecules were thought to form life.

Let’s analyse the question to find the correct answer.
> In Miller-Urey experiment, the experimental design consisted of the introduction of atmospheric gases which are thought to exist in the early earth into a closed chamber.
> Methane $(C{{H}_{4}})$ , Hydrogen (H) and ammonia \[(N{{H}_{3}})\] gases were introduced into an environment containing water vapour $({{H}_{2}}O)$ which evaporated from the water filled container of the chamber.
> Primitive earth atmosphere was oxygenless, so they did not use oxygen gas. To simulate primitive lightning conditions, Miller provided the system with electric current using tungsten electrodes.
> After a few days Miller observed the flask contained organic compounds such as amino acids which are the building blocks of proteins.
> Therefore, among the options given in the question, I. Hydrogen gas, III. Methane, IV. Ammonia is correct. And II. Hydrogen is incorrect.

Thus, option C. I, III and IV is the correct answer.

Note: The compounds which are newly formed during the experiment dissolved in the water and accumulated in the flask. Chromatographic analysis of these confirmed the formation of amino acids like glycine, alanine, aspartic acid, glutamic acid, beta alanine as well as other organic compounds like urea, lactic acid, glycolic acid etc.