Pyrimidine dimers
A) block DNA replication and transcription.
B) can be repaired by photoreactivation.
C) can be repaired by nucleotide-excision repair.
D) All of the above

Question

Quizplus · Accepted Answer

Pyrimidine dimers, which are DNA lesions caused by exposure to UV radiation, can block DNA replication and transcription. However, they can be repaired by both photoreactivation (in which enzymes use light energy to break the dimer) and nucleotide-excision repair (in which enzymes remove the damaged section of DNA and replace it with new nucleotides). Therefore, the correct answer is D - all of the above.

Pyrimidine Dimers