Each new DNA molecule contains one original strand and one newly built strand, shown by Meselson and Stahl.
Meselson and Stahl (1958) grew E. coli in heavy nitrogen (15N) then moved them to 14N. After one generation, DNA had intermediate density; after two, half intermediate and half light. This ruled out conservative and dispersive models.
Each daughter helix retains one old strand, which ensures accurate copying.
Each new DNA molecule contains one original strand and one newly built strand, shown by Meselson and Stahl.
Semi-Conservative Replication is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include DNA Replication, Homologous Recombination, Helicase and Topoisomerase.
Centrifugation in caesium chloride separated the DNA bands by density.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Semi-Conservative Replication. Intermediate topics assume the Beginner vocabulary.
The closest topics to Semi-Conservative Replication are DNA Replication, Homologous Recombination, Helicase and Topoisomerase, Leading and Lagging Strands. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Semi-Conservative Replication. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Semi-Conservative Replication: Each new DNA molecule contains one original strand and one newly built strand, shown by Meselson and Stahl. DNA Replication: The copying of DNA before cell division so each daughter cell receives a full set of genes. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with DNA Replication and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
The copying of DNA before cell division so each daughter cell receives a full set of genes.
🧫 Molecular BiologyAn accurate repair pathway and meiotic mechanism exchanging DNA between similar sequences using RAD51.
🧫 Molecular BiologyHelicase unwinds the double helix at the fork while topoisomerase relieves the supercoiling strain ahead of it.
🧫 Molecular BiologyThe leading strand is made continuously, while the lagging strand is made in short Okazaki fragments.
🧫 Molecular Biology