"DNA ligase is what binds the discontinuous fragments also called Okazaki fragments my friend. base-pairing is the hydrogen bonding that happens between the nucleotides of two strands; C triple bond G and A double bond T. Replication fork contains DNA Polymerase and other factors which bind to 3'-OH and starts the addition of nucleotides on the new strand. helicase is like a stone it holds the unwind two strands apart. topoisomerase is like helicase but it unwinds complex winds b4 helicase. wish I've helped. ::)"