Final answer:
DNA polymerase's role in the removal of mismatched nucleotides involves its proofreading function, where it employs a 3' exonuclease activity to remove an incorrectly paired nucleotide and then adds the correct one.Option 2 is the correct answer.
Step-by-step explanation:
The role of DNA polymerase in the removal of mismatched nucleotides is through its proofreading activity. During DNA replication, DNA polymerase can make mistakes while adding nucleotides. It checks the newly added base for correct pairing with the base in the template strand. If the base is incorrect, DNA polymerase uses its 3' exonuclease activity to remove the mismatched nucleotide. After the incorrect base is excised, DNA polymerase can then add the correct nucleotide before continuing with replication. Therefore, the correct answer to the student's question is that DNA polymerase removes the mismatched nucleotide, which corresponds to option 2).
DNA polymerase plays a crucial role in maintaining the fidelity of DNA replication through its proofreading activity. During the intricate process of DNA replication, errors can occur as DNA polymerase synthesizes the new DNA strand. To rectify these mistakes, DNA polymerase employs proofreading mechanisms. After adding a nucleotide, it scrutinizes its pairing with the template strand.
If a mismatch is detected, the polymerase utilizes its 3' exonuclease activity to excise the erroneous nucleotide. This removal allows for the subsequent insertion of the correct nucleotide, ensuring the accuracy of the genetic code. This proofreading function exemplifies the precision and efficiency with which DNA polymerase contributes to the faithful replication of genetic information.