Final answer:
Statement B is TRUE for eukaryotic transcription-linked nucleotide excision repair. Yeast Rad4 recognizes damaged DNA, such as thymine dimers, and is involved in the repair process, which also exists in other eukaryotic organisms. The other statements provided are not accurate descriptions of the NER process.
Step-by-step explanation:
The process of eukaryotic transcription-linked nucleotide excision repair (NER) is aimed at repairing damage that affects longer strands of DNA bases, especially bulky, helix-distorting lesions like thymine dimers. This type of damage repair is crucial because if left unrepaired, it can lead to mutations that may result in cancer in organisms, particularly when exposed to UV light. In eukaryotes, this process involves several steps, where damaged DNA is recognized, excised, and then resynthesized using the undamaged strand as a template.
Answering the student question, statement B is TRUE: Yeast Rad4 recognizes damaged DNA and this process involves flipping out thymine dimers. Rad4 in yeast is an ortholog to the human XPC protein, which recognizes the damaged DNA in global genomic NER, though this process also plays a crucial role in transcription-coupled NER as it helps identify lesions obstructing the transcription machinery. The removal of thymine dimers, a common form of UV-induced damage, is a key function of NER.
As for the other choices: A is false because the global genome repair pathway does share common steps with transcription-linked nucleotide excision repair. C is incorrect because in eukaryotic nucleotide excision repair, the DNA is typically resynthesized by DNA polymerase Δ or Ε, not by DNA polymerase V, which is involved in certain types of damage tolerance in bacteria. D confuses elements of the process: while RNA polymerase can stall during transcription due to damage, resulting in TCR, it is not commonly degraded. Instead, repair factors, including the TFIIH complex, are recruited to the site to initiate repair.