AP BIOLOGY

Detailed explanation-1: -So, the correct answer is ‘Ammonia, methane, hydrogen and water vapour’.

Detailed explanation-2: -Miller and Urey combined what they believed to be the major components of the earth’s early atmosphere-water (H2O), methane (CH4), hydrogen (H2), and ammonia (NH3)-and sealed them in a sterile flask.

Detailed explanation-3: -Miller’s test was set up to mimic the atmosphere of the early Earth. Due to Urey’s hypothesis, Miller did not include oxygen as part of his experiment. He placed hydrogen, boiling water, methane and ammonia into an enclosed chamber (chem.duke.edu).

Detailed explanation-4: -In November 2020, a team of international scientists reported their study on oxidation of the magma around 4.5 billion years ago suggesting that the original atmosphere of the Earth contained little amount of oxygen and no methane or ammonia as presumed in the Miller–Urey experiment.

Detailed explanation-5: -The experiments reported were conducted by Stanley L. Miller, then a graduate student working under the direction of Harold C. Urey at the University of Chicago chemistry department. The mixture of gases used was methane, ammonia, water and hydrogen.