Final answer:
In nucleotide excision repair, the undamaged complementary DNA strand serves as the template for the synthesis of new DNA, which is then sealed into the existing strand by DNA ligase.
Step-by-step explanation:
In nucleotide excision repair, the template for the synthesis of new DNA to replace the damaged strand is the undamaged complementary strand. When DNA damage occurs, such as the formation of pyrimidine dimers due to UV exposure, an enzyme complex recognizes the distortion and removes the damaged section of the strand. DNA polymerase then synthesizes new DNA using the undamaged complementary strand as a template. The new DNA is synthesized in the 5' to 3' direction, ensuring the correct base-pairing with the undamaged strand. Finally, DNA ligase seals the newly synthesized DNA into the existing DNA strand by creating a phosphodiester bond.
In nucleotide excision repair, the template for synthesis of new DNA to replace the damaged strand is the complementary strand of the DNA double helix. The damaged nucleotides are removed, and the complementary strand is used as a guide to replace them with undamaged nucleotides.