MHT CET 202623 AprilMorning Shift
- Exam
- MHT CET
- Year
- 2026
- Date
- 23 April
- Shift
- Morning Shift
- Subject
- Biology
- Chapter
- Molecular Basis of Inheritance
MHT CET 2026 · 23 April · Morning Shift · Biology · Molecular Basis of Inheritance
Meselson and Stahl proved the semi-conservative nature of DNA...
Meselson and Stahl proved the semi-conservative nature of DNA replication using the isotope ___.
Options
- A^{32}
- B^{35}
- C^{14}
- D^{15}
Correct answer
D. ^{15}
Step-by-step solution
Meselson and Stahl performed an experiment in 1958 to prove the semi-conservative nature of DNA replication.
They grew E. coli in a medium containing ( is the heavy isotope of nitrogen) for many generations. The result was that was incorporated into newly synthesized DNA (as well as other nitrogen-containing compounds). This heavy DNA molecule could be distinguished from the normal DNA by centrifugation in a cesium chloride (CsCl) density gradient.
Therefore, the isotope used was .
Answer:
They grew E. coli in a medium containing ( is the heavy isotope of nitrogen) for many generations. The result was that was incorporated into newly synthesized DNA (as well as other nitrogen-containing compounds). This heavy DNA molecule could be distinguished from the normal DNA by centrifugation in a cesium chloride (CsCl) density gradient.
Therefore, the isotope used was .
Answer: