The first cellular forms of life appeared on earth about

Options

A. 500 mya
B. 2000 mya
C. 2500 mya
D. 350 mya

Answer

To determine when the first cellular forms of life appeared on Earth, we can analyze the options provided and the relevant biological history.

### Step-by-Step Solution:

1. **Understanding Cellular Life**: The question asks about the first cellular forms of life, specifically focusing on prokaryotic cells, which are single-celled organisms without a nucleus.

2. **Analyzing the Options**:
- **500 MYA (Million Years Ago)**: This period is known for the evolution of the first fish, which is much later than the appearance of the first cellular life.
- **2000 MYA**: This option is significant because it aligns with the emergence of the first living cells, specifically prokaryotic cells.
- **2500 MYA**: While this period is notable for the production of oxygen due to photosynthesis, it does not specifically indicate the emergence of cellular life.
- **350 MYA**: This time frame is associated with the evolution of reptiles and seed ferns, which again is much later than the first cellular life.

3. **Identifying the Correct Answer**: Based on the analysis, the first cellular forms of life, specifically prokaryotic cells, are believed to have appeared around **2000 million years ago**.

### Final Answer:
The first cellular forms of life appeared on Earth about **2000 million years ago**.

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