Nucleus as a cell organelle was first described by

Options

A. Robert Hooke
B. Robertson
C. Rausburg
D. Robert Brown

Answer

To answer the question "Nucleus as a cell organelle was first described by," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the first person to describe the nucleus as a cell organelle.

2. **Identifying the Options**: The options provided are:
- Robert Hooke
- Robert Sun
- Rossberg and Rouseberg
- Robert Brown

3. **Researching the History of Cell Discovery**:
- Robert Hooke is known for his work with cork cells and for coining the term "cell," but he did not discover the nucleus.
- Robert Brown, a Scottish botanist, is known for his discovery of the nucleus in plant cells in 1831.
- The other names (Robert Sun, Rossberg, and Rouseberg) do not have significant historical contributions related to the discovery of the nucleus.

4. **Conclusion**: Based on historical records, Robert Brown is credited with the discovery of the nucleus as a cell organelle.

5. **Final Answer**: The correct answer is **Robert Brown**.