Teaching MPPSC Assistant Professor Mock Test Series 2025 Life Sciences Fundamental Processes DNA replication, repair and recombination
In the context of DNA repair mechanisms, which of the following statements accurately describes the role and mechanism of the nucleotide excision repair (NER) pathway in eukaryotic cells?
1
NER primarily corrects DNA base mismatches that occur during DNA replication by removing the incorrect base and resynthesizing the correct one using the opposite strand as a template.
2
NER is responsible for the repair of double-strand breaks through a process that involves recombination with an undamaged sister chromatid to ensure error-free repair.
3
NER detects and removes bulky lesions, such as those caused by UV light-induced thymine dimers, by excising a short single-stranded DNA segment containing the damage and subsequently filling in the gap using the undamaged strand as a template.
4
NER exclusively repairs DNA damage in actively transcribing genes through the transcription-coupled repair (TCR) subpathway, which identifies lesions by stalling RNA polymerase.