In 1953, Stanley Miller and Harold Urey performed an experiment at the University of Chicago to test the hypothesis that the conditions of the early Earth would have favored the formation of larger, more complex organic molecules from basic precursors. The experiment, shown in Figure 1, consisted of sealing basic organic chemicals (representing the atmosphere of the primitive Earth) in a flask, which was exposed to electric sparks (to simulate lightning) and water vapor.

After one day of exposure, the mixture in the flask had turned pink in color, and later analysis showed that at least 10% of the carbon had been transformed into simple and complex organic compounds including at least 11 different amino acids and some basic sugars. No nucleic acids were detected in the mixture.

Which of the following contradicts the hypothesis of the experiment that life may have arisen from the formation of complex molecules in the conditions of the primitive Earth?

formation of complex molecules in the conditions of the primitive Earth?
(A) Complex carbon-based compounds were generated after only one day of exposure to simulated primitive Earth conditions.
(B) Nucleic acid compounds such as DNA and RNA were not detected in the mixture during the experiment.
(C) Over half of known amino acids involved in life were detected in the mixture during the experiment.
(D) Basic sugar molecules were generated and detected in the mixture during the experiment.

Transcribed Image Text:

H₂O Vapor Electrical Source Primitive Earth Gases (H₂O Vapor, NH3, CH4, Hạ, CO) Vent for Recycling with Incoming H₂O Vapor