Multiple Choice
In the context of DNA repair during replication, which mechanism most directly helps prevent errors in DNA replication by removing misincorporated nucleotides as DNA is being synthesized?
13
views
17. Mutation, Repair, and Recombination
DNA Repair
Multiple Choice
Which of the following repair pathways repairs damage that causes distortions in the double helix?
A
Base Excision Repair
B
Nucleotide Excision Repair
C
Mismatch Repair
D
Homologous Recombination
Verified step by step guidance1
Understand the types of DNA damage: Distortions in the double helix are often caused by bulky adducts or thymine dimers, which are typically the result of UV radiation or chemical exposure.
Identify the repair mechanisms: Different repair pathways are specialized for different types of DNA damage. Base Excision Repair (BER) fixes small, non-helix-distorting base lesions. Mismatch Repair (MMR) corrects base mismatches that occur during DNA replication. Homologous Recombination (HR) is involved in repairing double-strand breaks.
Focus on Nucleotide Excision Repair (NER): This pathway is specifically designed to remove bulky DNA adducts and thymine dimers that cause significant distortions in the DNA double helix.
NER process overview: NER involves the recognition of the distortion, excision of a short single-stranded DNA segment containing the lesion, and synthesis of a new DNA strand using the undamaged strand as a template.
Conclude with the correct pathway: Given the nature of the damage (distortions in the double helix), Nucleotide Excision Repair is the appropriate repair mechanism.
Related Videos
Related Practice
