Miller performed experiment to prove abiogenetic molecular evolution of life. Which molecule was not present in Miller's experiment

Options

A. Water
B. Methane
C. Oxygen
D. Ammonia

Answer

**Step-by-Step Solution:**

1. **Understanding Miller's Experiment**: The experiment conducted by Stanley Miller aimed to simulate the conditions of early Earth to explore the abiogenetic origins of life. He was inspired by the theories of Oparin and Haldane, which suggested that life arose from non-living chemical substances.

2. **Identifying the Components Used**: In Miller's setup, he included several gases that were believed to be present in the early Earth's atmosphere. These gases included methane (CH₄), ammonia (NH₃), hydrogen (H₂), and water vapor (H₂O).

3. **Recognizing the Absence of Oxygen**: The key point of Miller's experiment was that it was designed to replicate a primordial environment that lacked free oxygen. Oxygen was not included in the experiment because it was not thought to be present in significant amounts in the early atmosphere.

4. **Conclusion**: Therefore, the molecule that was not present in Miller's experiment is oxygen (O₂). This absence was crucial for simulating the conditions under which life might have originated, as the presence of oxygen could lead to oxidation reactions that would hinder the formation of organic compounds.

**Final Answer**: The molecule that was not present in Miller's experiment is **oxygen**.

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