The year 2003 was celebrated as the `50^(th)` anniversary of discovery of

Options

A. transponsons by Barbara Mc Cliontock
B. structure of DNA by Watson and Crick
C. Mendel's laws of inheritance
D. biotechnology by Kary Mullis.

Explanation

To solve the question regarding the 50th anniversary celebrated in 2003, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Year of Discovery**: The question states that 2003 marks the 50th anniversary of a significant scientific discovery. To find the original year of discovery, we subtract 50 from 2003:
\[ 2003 - 50 = 1953 \]
This means we need to identify what was discovered in 1953.

2. **Recall Major Discoveries in 1953**: The year 1953 is notable for several scientific advancements. However, the most significant one is the discovery of the structure of DNA.

3. **Recognize Key Contributors**: The structure of DNA was proposed by James Watson and Francis Crick in 1953. They developed the double helix model based on X-ray diffraction data provided by Rosalind Franklin and Maurice Wilkins.

4. **Evaluate the Options**: The options provided in the question include:
- Transposons by Barbara McClintock
- Structure of DNA by Watson and Crick
- Mendel's law of inheritance
- Biotechnology by Gary Mullis

Among these, the second option (structure of DNA by Watson and Crick) corresponds to the discovery made in 1953.

5. **Confirm the Answer**: Since the question specifically asks for the 50th anniversary celebrated in 2003, and we have established that the structure of DNA was discovered in 1953, we conclude that the correct answer is:
\[ \text{Option 2: Structure of DNA by Watson and Crick} \]

### Final Answer:
The year 2003 was celebrated as the 50th anniversary of the discovery of the structure of DNA by Watson and Crick.

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