Question

Statement 1: Avery, McLeod, and McCarty discovered the semi-conservative nature of DNA.
Statement 2: Meselson and Stahl used \( \text{E. coli} \) to demonstrate the semi-conservative nature of DNA.

• A. Statement 1 is correct, Statement 2 is incorrect
• B. Statement 2 is correct, Statement 1 is incorrect
• C. Both statements are correct
• D. Both statements are incorrect

Hint:

Avery et al. established DNA as genetic material, while Meselson and Stahl demonstrated its semi-conservative replication.

Answer 1

The Correct Option is B

Statement 1: Avery, McLeod, and McCarty discovered the semi-conservative nature of DNA.

Statement 2: Meselson and Stahl used E. coli to demonstrate the semi-conservative nature of DNA.

Analysis:

• Statement 1 is incorrect. Avery, McLeod, and McCarty demonstrated that DNA, not protein, is the genetic material. They did not discover the semi-conservative nature of DNA replication.
• Statement 2 is correct. Meselson and Stahl conducted experiments using E. coli and isotopes of nitrogen to prove that DNA replication is semi-conservative.

Therefore, the correct answer is:

Option 2: Statement 2 is correct, Statement 1 is incorrect