Semiconservative replication of DNA was given by

Options

A. Watson and Crick
B. Bateson and Punnet
C. Messelson and stahls
D. Avery, McCarty and MacLeod

Answer

To determine who proposed the semiconservative replication of DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Semiconservative Replication**:
- Semiconservative replication is a method of DNA replication where each of the two strands of the DNA molecule serves as a template for the creation of a new complementary strand. This results in two DNA molecules, each containing one original (parent) strand and one newly synthesized strand.

2. **Identify the Scientists Involved**:
- The question provides four options: Watson and Crick, Bateson and Punnett, Meselson and Stahl, and Avery, McCarty, and MacLeod. We need to evaluate which of these scientists is associated with the discovery of semiconservative replication.

3. **Evaluate Each Option**:
- **Watson and Crick**: They are known for elucidating the double-helix structure of DNA, not for the replication mechanism.
- **Bateson and Punnett**: They are known for their work on genetic linkage and inheritance patterns, not DNA replication.
- **Meselson and Stahl**: They conducted experiments that demonstrated the semiconservative nature of DNA replication using isotopes of nitrogen to label DNA strands.
- **Avery, McCarty, and MacLeod**: They are known for their work in identifying DNA as the transforming principle in bacteria, not for replication.

4. **Conclusion**:
- Based on the evaluations, the correct answer is **Meselson and Stahl**. They provided the experimental evidence for the semiconservative model of DNA replication.

### Final Answer:
The semiconservative replication of DNA was given by **Meselson and Stahl**.

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