Final answer:
The initial mechanism for repairing nucleotide errors in DNA is nucleotide excision repair. Nucleotide excision repair removes damaged bases by making a cut on both ends of the damaged base and replacing it with the correct nucleotides.
Step-by-step explanation:
The initial mechanism for repairing nucleotide errors in DNA is nucleotide excision repair. Nucleotide excision repair is used to remove damaged bases, such as those caused by UV exposure, by making a cut on both ends of the damaged base. The segment of DNA with the damaged base is then removed and replaced with the correctly paired nucleotides by the action of DNA polymerase.