Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

8. DNA Replication

Semiconservative Replication

Genetics

8. DNA Replication

Semiconservative Replication

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Multiple Choice

Which of the following experiments showed that DNA replicated via semiconservative replication?

Hershey/Chase

Francis/Crick

Meselson-Stahl

T.H. Morgan

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Verified step by step guidance

Understand the concept of semiconservative replication: In semiconservative replication, each of the two strands of the DNA molecule serves as a template for the production of a complementary strand. As a result, each new DNA molecule consists of one old (parental) strand and one newly synthesized strand.

Identify the key experiment: The Meselson-Stahl experiment is the one that demonstrated semiconservative replication. This experiment used isotopes of nitrogen to distinguish between old and new strands of DNA.

Review the experimental setup: Meselson and Stahl grew E. coli in a medium containing heavy nitrogen (15N) and then transferred the bacteria to a medium with light nitrogen (14N). They then extracted DNA at various intervals to analyze its density using equilibrium density gradient centrifugation.

Analyze the results: After one round of replication in 14N, the DNA consisted of hybrid molecules (one strand with 15N and one with 14N), indicating semiconservative replication. After a second round, there were both hybrid molecules and molecules with only 14N, further supporting the semiconservative model.

Conclude the significance: The Meselson-Stahl experiment provided strong evidence for the semiconservative model of DNA replication, distinguishing it from conservative and dispersive models.