Final answer:
Nucleotide excision repair is the repair mechanism that uses complexes instead of single enzymes for repair. It removes damaged bases caused by UV exposure.
Step-by-step explanation:
The repair mechanism that uses complexes instead of single enzymes for repair is the nucleotide excision repair system. Nucleotide excision repair is used to remove damaged bases, such as those caused by UV exposure. Enzymes called excision nucleases recognize the damaged bases, make a cut on both ends of the damage, and remove the segment of DNA. The DNA polymerase then fills in the gap with the correct nucleotides, and DNA ligase seals the gap.