Why did the Miller‒Urey hot chemistry experiment exclude oxygen in its investigation of the chemical origin of life on Earth?
A) Oxygen is not necessary for life.
B) The scientists assumed the reactions would produce oxygen from water vapor.
C) The scientists assumed that photosynthetic organisms would develop in the apparatus.
D) There is no evidence that oxygen existed in Earth's earliest environments.
E) The scientists wanted to avoid contamination of the apparatus by oxygen-consuming bacteria.

Question

Quizplus · Accepted Answer

There is no evidence that oxygen existed in Earth's earliest environments. The Miller-Urey experiment was designed to simulate the conditions of Earth's early atmosphere, which was primarily composed of methane, ammonia, and water vapor, but not oxygen. Therefore, excluding oxygen from the experiment more accurately reflected the early conditions on Earth.

Why Did the Miller‒Urey Hot Chemistry Experiment Exclude Oxygen in Its