Ribosomes were first observed under the EM as dense particles by

Options

A. Robert Brown
B. Camillo Golgi
C. George Palade
D. T.O. Diener

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who first observed ribosomes under an electron microscope (EM) as dense particles.

2. **Identifying the Scientists**: The options provided are Robert Brown, Camillo Golgi, George Palladotti, and Diener. We need to evaluate their contributions to determine who observed ribosomes.

3. **Evaluating Each Scientist**:
- **Robert Brown**: Known for discovering the nucleus in cells, not ribosomes.
- **Camillo Golgi**: Recognized for discovering the Golgi apparatus, not related to ribosomes.
- **George Palladotti**: He is credited with the discovery of ribosomes under the electron microscope.
- **Diener**: Associated with the discovery of the causative agent of potato spindle tuber disease, not ribosomes.

4. **Conclusion**: Based on the contributions of each scientist, George Palladotti is the one who first observed ribosomes under the electron microscope as dense particles.

5. **Final Answer**: Ribosomes were first observed under the electron microscope as dense particles by George Palladotti in 1953.

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