The data obtained from the meselson–stahl experiment after one generation of replication eliminated the dispersive model of dna

Question

viktelen [127]

3 years ago

14

The data obtained from the meselson–stahl experiment after one generation of replication eliminated the dispersive model of dna

replication. True or False

Biology

2 answers:

svetlana [45] · Answer 1 · 2022-04-26T18:01:23+03:00

Answer:

<h2>False</h2>

Explanation:

Meselson-stahl experiment: The experiment done by Meselson and Stahl demonstrated that DNA replicated semi-conservatively, meaning that each strand in a DNA molecule serves as a template while DNA replication for synthesis of a new, complementary strand.

The conservative model was eliminated because according to it, there would be 2 bands, one representing the parental DNA at one density and other representing the daughter DNA at a different density. The result from the Meselson–Stahl experiment after one generation was consistent with both the semi-conservative as well the dispersive model.

Sedaia [141] · Answer 2 · 2022-04-26T16:20:50+03:00

<h2>Given statement is false</h2>

Explanation:

According to dispersive model of DNA replication,DNA molecules are hybrids of parental and daughter DNA;In this model each individual strand is a combination of original and new DNA

Meselson and Stahl did an experiment on DNA replication using E.coli bacteria

E.coli was grown in a medium containing heavy isotope of nitrogen,bacteria took up the nitrogen and used to synthesize new biological molecules,including DNA
It was grown for many generations,the nitrogenous bases of the bacteria's DNA were all labelled with heavy nitrogen
Bacteria were then switched to light nitrogen isotope and allowed to grow for several generations
They then measured the density of the DNA using density gradient centrifugation
This method separates molecules such as DNA into bands by spinning them at high speeds in the presence of another molecule, such as cesium chloride
Each DNA produced two DNA molecules each with one new strand and one old strand called semi conservative replication(half of the parental DNA conserved in daughter DNA)
Each DNA strand act as a template for synthesis of new strand
Hence,dispersive model of DNA was eliminated and semi-conservative model of DNA replication was proved by the above experiment