Eliminate incorrect options: The statement 'It adds nucleotides to the 3' end of the growing DNA strand during replication' refers to DNA polymerase, not RNA polymerase. The statement 'It unwinds the double helix and joins Okazaki fragments' describes processes in DNA replication, not transcription. The statement 'It translates mRNA into a polypeptide chain' refers to the process of translation, not transcription.