Table of contents

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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

17. Mutation, Repair, and Recombination

DNA Repair

Genetics

17. Mutation, Repair, and Recombination

DNA Repair

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Multiple Choice

Which enzyme creates nicks ahead of the replication fork to relieve tension from DNA unwinding during replication?

Helicase

Topoisomerase

Primase

DNA ligase

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Verified step by step guidance

Understand the role of each enzyme listed in the context of DNA replication.

Recall that Helicase unwinds the DNA double helix by breaking hydrogen bonds between base pairs, but does not relieve tension ahead of the fork.

Recognize that Primase synthesizes RNA primers needed to start DNA synthesis, but does not affect DNA tension.

Know that DNA ligase joins Okazaki fragments on the lagging strand but does not relieve supercoiling tension.

Identify that Topoisomerase is the enzyme that creates temporary nicks ahead of the replication fork to relieve the torsional strain caused by unwinding, preventing DNA tangling and supercoiling.