Miller-Urey Experiment - Practice Questions & MCQ

The Oparin-Haldane Theory:

• In the 1920s British scientist, J.B.S. Haldane and Russian biochemist Oparin independently provided similar ideas regarding the conditions required for the origin of life on Earth. 
• Both believed that organic molecules could be formed from abiogenic materials in the presence of an external energy source (e.g., ultraviolet radiation) and that the primitive atmosphere was reducing (having very low amounts of free oxygen) and contained ammonia, water vapour, nitrogen, hydrogen, methane, ammonia, carbon dioxide.
• The early simple molecules interacted with each other and produced simple organic molecules such as simple sugars, nitrogen bases, amino acids, glycerol, fatty acids, etc.
• Both also suspected that the first life-forms appeared in the warm, primitive ocean and were heterotrophic rather than autotrophic.
• A soup-like broth of chemicals formed in oceans of the early earth from which living cells are believed to have appeared. It was termed by Haldane as ‘prebiotic soup’ or ‘hot dilute soup’.

The Miller-Urey Experiment:

• In 1953 American chemists Harold C. Urey and Stanley Miller tested the Oparin-Haldane theory and successfully produced organic molecules from some of the inorganic components thought to have been present on prebiotic Earth.
• In their experiment, they combined warm water with a mixture of four gases—water vapour, methane, ammonia, and molecular hydrogen—and provided the “atmosphere” with electrical discharges.  
• One week later Miller and Urey found that simple organic molecules, including amino acids (the building blocks of proteins), had formed under the simulated conditions of early Earth.