Who crystallised and isolated viruses for the first time?

Options

A. W.M. Stanley
B. K.M. Smith
C. D. Ivanowski
D. F.C. Bawden

Answer

### Step-by-Step Solution:

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

2. **Recall Historical Context**: The crystallization of viruses is a significant milestone in virology. It is important to remember the year and the scientist associated with this discovery.

3. **Research the Scientist**: The scientist who first crystallized viruses is Wendell Meredith Stanley.

4. **Year of Discovery**: This groundbreaking work was accomplished in the year 1935.

5. **Understanding the Significance**: Stanley's work demonstrated that viruses are largely composed of proteins, which allowed them to be crystallized. This was a crucial step in understanding the structure and function of viruses.

6. **Conclusion**: Therefore, the answer to the question is Wendell Meredith Stanley, who crystallized and isolated viruses for the first time in 1935.

### Final Answer:
Wendell Meredith Stanley crystallized and isolated viruses for the first time in 1935.

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