The first cell-like structures appeared in

Options

A. Air
B. Mountains
C. Oceans
D. Soil

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the first cell-like structures that appeared on Earth.

2. **Identifying the First Cell-like Structures**: The first cell-like structures are believed to be blue-green algae, also known as cyanobacteria. These organisms are significant because they are among the earliest forms of life on Earth.

3. **Location of Origin**: The blue-green algae originated in water, specifically in oceans. This is crucial as it indicates that the environment played a key role in the development of early life forms.

4. **Conditions for Formation**: Prior to the formation of these cell-like structures, the Earth's atmosphere contained nitrogen, oxygen, and water. Under certain conditions, such as lightning, these elements could combine to form amino acids and other organic compounds, which are essential for life.

5. **Conclusion**: Therefore, the first cell-like structures appeared in water, specifically in the oceans. This leads us to conclude that the correct answer to the question is "water".

**Final Answer**: The first cell-like structures appeared in water (specifically in the oceans).

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