Question

Which technique was used by Messelson –Stahl for discovering the mode of

replication?​

Answer 1

Answer:

The Meselson-Stahl experiment for discovering the semi-conservative model of DNA Replication

Explanation:

They proved that the DNA synthesized is by semi-conservative replication.

One strand of duplex passed on and changed to each of the daughter cells. This conserved strand act as a template for the synthesis of a new, complementary strand by the enzyme DNA polymerase.

*Detailed Explanation:*

This experiment is simply based on tagging the DNA and separating them based on their densities relative to the solution created by using Cesium Chloride.

It was a known fact by then that DNA is made up of nucleotides and these nucleotides contained nitrogen.

Meselson and Stahl utilized the common nitrogen by replacing it with a heavier isotope so that they can identify the parent and daughter DNA in solution by mixing the DNAs of different densities.

They experimented using simple techniques as ultra-centrifugation and density grading.

This experiment is a great milestone in modern biology as those were early times when atomic physics was applied in biological studies. Meselson and Stahl made three major outcomes.

DNA is made up of two strands, which was based on the Watson and Crick Model

If the parent DNA has two strands, then each of the strand acts as a template and retains its integrity and forms a daughter strand. Thus, the semi-conservation is evident

Each of the parent DNA strand is shared by two daughter DNA.