Final answer:
Nucleotide Excision Repair involves detection of damage, removal of damaged DNA, and synthesis of new DNA followed by ligation.
Step-by-step explanation:
The three main steps of Nucleotide Excision Repair (NER) are detection, excision, and synthesis. First, the DNA damage, such as thymine dimers caused by UV exposure, is detected by enzymes.
Next, an excision nuclease hydrolyzes the phosphodiester bonds several bases away from either side of the damage, and the segment of DNA containing the damaged bases is removed.
DNA polymerase then synthesizes new DNA using the undamaged strand as a template. Finally, DNA ligase seals the new DNA fragment into place by creating a new phosphodiester linkage, restoring the integrity of the DNA molecule.