Question

Meselson and Stahl used which radio isotopes for their experiment?

• (A) N¹⁵
• (B) O¹⁸
• (C) C¹⁴
• (D) All of these

Answer 1

The Correct Option is A

Explanation:
N¹⁵ is the heavy isotope of nitrogen which is used by Meselson and Stahl.Matthew Meselson and Franklin Stahl experiments that DNA replicates semi-conservatively. Semi-conservative DNA means half of the DNA is conserved.They used heavy isotope (nitrogen-15) and Cairns used radioactive thymidine.Due to the replication of DNA, two DNA molecules were found in which 50% radioactivity was discovered.When these two DNA molecules were made to replicate, the next time four DNA molecules were produced. Out of this 4 DNA, 2 DNA molecules were radioactive and the other 2 are not.And after that also, the  DNA molecules which is obtained were further replicated then also the number of radioactive DNA was 2.Hence, the correct option is (A).