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

17. Mutation, Repair, and Recombination

DNA Repair

Genetics

17. Mutation, Repair, and Recombination

DNA Repair

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Multiple Choice

In an experiment comparing DNA samples before and after exposure to a DNA-damaging agent, under which condition would the DNA bands on a gel be identical?

If the DNA is completely degraded by nucleases

If the DNA is not replicated during the experiment

If the DNA repair mechanisms successfully restore the original DNA sequence

If the DNA is exposed to UV light without any repair enzymes present

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Verified step by step guidance

Understand that DNA bands on a gel represent fragments of DNA separated by size, so identical bands mean the DNA fragments have the same length and sequence pattern before and after treatment.

Consider the effect of DNA degradation by nucleases: this would break DNA into smaller pieces, changing the band pattern, so bands would not be identical.

Consider the effect of DNA not being replicated: lack of replication alone does not change the DNA sequence or fragment sizes, but damage could still alter bands if repair does not occur.

Analyze the condition where DNA repair mechanisms successfully restore the original DNA sequence: this means any damage caused by the agent is fixed, so the DNA fragments remain the same, resulting in identical bands.

Evaluate the effect of UV light exposure without repair enzymes: UV causes damage like thymine dimers, which alter DNA structure and fragment sizes, so bands would differ from the original.