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प्रश्न
Discuss the significance of heavy isotope of nitrogen in the Meselson and Stahl’s experiment.
उत्तर
Matthew Meselson and Franklin Stahl performed the following experiment in 1958. They grew E. coli in a medium containing 15NH4Cl (15N is the heavy isotope of nitrogen) as the only nitrogen source for many generations. The result was that 15N was incorporated into newly synthesised 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 15N is not a radioactive isotope, and it can be separated from 14N only based on densities).
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संबंधित प्रश्न
Draw a labelled diagram of a “replicating fork” showing the polarity.
Name two enzymes involved in the process of DNA replication along with their properties.
Escherichia coli fully labelled with N15 is allowed to grow in N14 medium. The two strands of DNA molecule of the first generation bacteria have ______.
Out of 8 ascospores formed in Neurospora the arrangement is 2a : 4a : 2a showing ______.
Which of the following phenomena was experimentally proved by Meselson and Stahl?
DNA replication takes place at ______ phase of the cell.
If Meselson and Stahl's experiment is continued for sixth generations in bacteria, the ratio of Heavy strands 15N/15N: Hybrid15N/14N: light 14N/14N containing DNA in the sixth generation would be ______
The origin of replication of DNA in E. coli is shown below, Identify the labelled parts (i),(ii), (iii), and (iv)
The experimental proof for semi-conservative replication of DNA was first shown in a ______
During which phase of the cell cycle, does DNA replication take place?
