Viruses were first Crystallised by

Options

A. Leeuvenhock
B. lvanowsky
C. Beijerinck
D. Stanley

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks who was the first person to crystallize viruses.

2. **Recall Relevant Information**: The key figure associated with the crystallization of viruses is W. M. Stanley.

3. **Provide the Year of Achievement**: W. M. Stanley crystallized viruses in the year 1935.

4. **Explain the Significance**: Stanley's work demonstrated that viruses could be crystallized and that these crystals primarily consist of protein particles.

5. **Differentiate from Other Scientists**:
- Leeuwenhoek was known for isolating bacteria, not viruses.
- Iwanowski recognized small microorganisms smaller than bacteria causing diseases in plants (specifically tobacco mosaic disease) in 1892.
- Beijerinck furthered this by showing that the disease could be transferred through infected fluids.

6. **Conclude with the Answer**: Therefore, the answer to the question is W. M. Stanley.

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