Microtubules were discovered by

Options

A. De Robertis and Franchi
B. Robert Brown
C. Kolliker
D. Palade

Answer

**Step-by-Step Solution:**

1. **Understanding Microtubules**: Microtubules are structural components of the cell, part of the cytoskeleton, and play crucial roles in maintaining cell shape, enabling cellular transport, and facilitating cell division.

2. **Identifying the Discoverers**: The question asks who discovered microtubules. We need to evaluate the options provided:
- **Option A**: D. Robertis and Frenchi
- **Option B**: Robert Brown
- **Option C**: Koliker
- **Option D**: Palladay

3. **Analyzing Each Option**:
- **D. Robertis and Frenchi**: They are credited with the discovery of microtubules, specifically the tubular structures in the cytoplasm.
- **Robert Brown**: Known for discovering the nucleus, which is often referred to as the "brain" of the cell.
- **Koliker**: Recognized for his discovery of mitochondria, the powerhouse of the cell.
- **Palladay**: Discovered ribosomes, which are involved in protein synthesis.

4. **Conclusion**: Based on the contributions of each scientist, it is clear that microtubules were discovered by D. Robertis and Frenchi. Therefore, the correct answer is **Option A**.

**Final Answer**: Microtubules were discovered by D. Robertis and Frenchi.

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