One-gene-one enzyme hypothesis was proposed by :-

Options

A. R.Franklin
B. Hershey and Chase
C. A.Garrod
D. Beadle and Tatum

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the origin of the "one-gene-one enzyme hypothesis." This hypothesis relates to the function of genes in controlling the synthesis of enzymes.

2. **Identifying the Options**: The options provided are:
- R. Franklin
- Hershey and Chase
- A. Garrod
- Beadle and Tatum

3. **Evaluating Each Option**:
- **R. Franklin**: Rosalind Franklin was known for her work on the structure of DNA, particularly through X-ray crystallography. She did not propose the one-gene-one enzyme hypothesis.
- **Hershey and Chase**: They conducted experiments that demonstrated DNA as the genetic material. They are not associated with the one-gene-one enzyme hypothesis.
- **A. Garrod**: Garrod is known for his work in the field of inborn errors of metabolism and for discovering alkaptonuria. While he contributed to genetics, he did not propose the one-gene-one enzyme hypothesis.
- **Beadle and Tatum**: George Beadle and Edward Tatum conducted experiments with the fungus Neurospora crassa and proposed the one-gene-one enzyme hypothesis, which states that each gene encodes a specific enzyme.

4. **Conclusion**: Based on the evaluations, the correct answer is **Beadle and Tatum**.

### Final Answer:
The one-gene-one enzyme hypothesis was proposed by **Beadle and Tatum**.

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