Which of the following pairs are correctly matched?
(i) Discovery of protoplasm - Kolliker (ii) Discovery of cell - Robert Hooke (iii) Cell theory - Schleiden and Schwann (iv) PPLO-Smallest cell in the world (v) Neuron - Largest cell in the world

Options

A. (i), (iii) and (iv) only
B. (i), (iii), (iv) and (v) only
C. (i), (ii) and (iv) only
D. (ii), (iii) and (iv) only

Explanation

To determine which of the given pairs are correctly matched, we will analyze each pair one by one:

1. **Discovery of protoplasm - Kolliker**
- This pair is **not correctly matched**. The discovery of protoplasm is attributed to **Julius von Sachs** and **Hugo von Mohl**, not Kolliker.

2. **Discovery of cell - Robert Hooke**
- This pair is **correctly matched**. Robert Hooke is indeed credited with the discovery of the cell in 1665 when he observed cork under a microscope.

3. **Cell theory - Schleiden and Schwann**
- This pair is **correctly matched**. The cell theory was formulated by **Matthias Schleiden** and **Theodor Schwann**, stating that all living organisms are composed of cells.

4. **PPLO - Smallest cell in the world**
- This pair is **correctly matched**. PPLO (Pleuropneumonia-like organism) is considered one of the smallest known cells.

5. **Neuron - Largest cell in the world**
- This pair is **not correctly matched**. While neurons can be the largest cells in the human body, they are not the largest cells in the world. The title of the largest cell is often attributed to the ostrich egg cell.

### Conclusion:
The correctly matched pairs are:
- (ii) Discovery of cell - Robert Hooke
- (iii) Cell theory - Schleiden and Schwann
- (iv) PPLO - Smallest cell in the world

### Final Answer:
The correct pairs are (ii), (iii), and (iv).

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