The semi-conservation model of DNA replication was given by Messelson and Stahl. They labeled the DNA with nitrogen isotopes 14 N and 15 N. The method of density gradient centrifugation was used for the isolation of DNA. The two parental strands will be separated during the replication of bacteria, therefore, one of the strands will be labeled with 15 N (high density band) and the other will be labeled as 14 N (low density band). The synthesis of the other strands will take place during DNA replication to form the intermediate bands in the first generation. In the second generation of replication, one low density band and one intermediate density band will be formed.

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Chapter 13, Problem 7TYU

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The semi-conservation model of DNA replication was given by Messelson and Stahl. They labeled the DNA with nitrogen isotopes ¹⁴N and ¹⁵N. The method of density gradient centrifugation was used for the isolation of DNA. The two parental strands will be separated during the replication of bacteria, therefore, one of the strands will be labeled with ¹⁵N (high density band) and the other will be labeled as ¹⁴N (low density band).

The synthesis of the other strands will take place during DNA replication to form the intermediate bands in the first generation. In the second generation of replication, one low density band and one intermediate density band will be formed.

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