Nucleus was first described as a cell organelle by

Options

A. Robert Brown
B. Flemming
C. Fontana
D. Waldeyer

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks who first described the nucleus as a cell organelle.

2. **Recall Relevant Information**: The nucleus is a vital organelle in eukaryotic cells, containing genetic material and playing a crucial role in cell regulation and function.

3. **Research Historical Context**: The nucleus was first described in the context of cell biology in the early 19th century.

4. **Identify Key Figures**: Among the scientists mentioned (Robert Brown, Fleming, Fontana, and Waldron), Robert Brown is noted for his contributions to the understanding of the nucleus.

5. **Confirm the Answer**: Robert Brown first described the nucleus as a cell organelle in 1831.

6. **Conclusion**: Therefore, the correct answer to the question is Robert Brown.

**Final Answer**: The nucleus was first described as a cell organelle by Robert Brown.

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