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

Options

A. (a) Oxygen
B. (b) Water
C. (c) Ammonia
D. (d) Methane

Answer

To solve the question regarding which molecule was not present in Miller's experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Miller-Urey Experiment**: The experiment was conducted by Stanley Miller and Harold Urey in 1952 to simulate the conditions of early Earth and explore the origins of life.

2. **Identify the Conditions Simulated**: The experiment aimed to replicate the primitive atmosphere of Earth, which was believed to be reducing. This means that it lacked free oxygen.

3. **List the Gases Used in the Experiment**: The main gases that were included in the Miller-Urey experiment were:
- Methane (CH₄)
- Ammonia (NH₃)
- Hydrogen (H₂)

4. **Recognize the Absence of Oxygen**: Since the primitive atmosphere was reducing, oxygen (O₂) was not present in the conditions simulated by Miller and Urey.

5. **Analyze the Options Given**: The question provides several options, and we need to identify which molecule was not included in the experiment. Since we established that oxygen was absent, we can conclude that:
- **Oxygen (O₂)** was not present in Miller's experiment.

6. **Final Answer**: Therefore, the molecule that was not present in Miller's experiment is **Oxygen (A)**.