Which of the following activities of DNA polymerase I allows

Which of the following activities of DNA polymerase I allows it to remove RNA primers during lagging strand synthesis?

3\'-->5\' endonuclease

3\' 5\' exonuclease

5\' 3\' endonuclease

5\' 3\' exonuclease

1\' 3\' endonuclease

Solution

It is 5\'-3\' exonuclease activity that removes primers during replication.

DNA polymerase I had 3 important activities: 5\'-3\' polymerase activity (adding DNA nucleotides to the DNA strand), 5\'-3\' exonuclease activity (removal of primers), 3\'-5\' exonuclease activity (proofreading activity)