Practice question

Lagging strand synthesis leaves behind RNA primers that must be removed to create contiguous DNA strand before ligation. In prokaryotes DNA polymerase I performs this task using intrinsic 5' to 3' exonuclease that degrades RNA while simultaneously polymerizing DNA forward process called nick translation efficiently replacing RNA with DNA. RNase H also can clip RNA primers but main removal during replication is Pol I specifically. Pol III lacks this forward exonuclease, Pol II has none. After Pol I fills gap, remaining nick sealed by NAD-dependent DNA ligase.