<prompt> Most impoant enzyme in DNA replication for chain elongationHelicaseDNA polymerase IDNA polymerase IIITopoisomerase III  <response>: Ans. is c i.e.,DNA polymerase III Impoant DNA PolymerasesIn ProkaryotesDNA polymerase I :- Helps in gap filling and synthesis between okazaki fragments of lagging strand, and replaces ribonucleotides of RNA primer by deoxyribonucleotides. It has i 3 5 exonuclease activity, ii 5 3 exonuclease activity and iii polymerase 5 - 3 polymerase activityDNA polymerase II:- Helps in i proof reading 3 5 exonuclease activity, and ii DNA repair.DNA polymerase III :- It is the main enzyme that synthesizes prokaryote DNA, i.e., synthesis of leading and lagging strand. It has i 5 - 3 polymerase or simply polymerase activity for DNA synthesis, and ii 3-5 exonuclease activity for proof reading.In EukaryotesDNA polymerase a :- It has primase activity i.e. synthesizes RNA primer, and initiates DNA synthesis.DNA polymerase p :- It is a DNA repair enzymeDNA polymerase y :- Replicates mitochondrial DNADNA polymerase ?:- Helps DNA synthesis on lagging strand, i.e. elongation of okazaki fragments on lagging strand. It also has 5-3 exonuclease activity for proof reading.DNA polymerase c :- Helps in DNA synthesis on leading strand. It also has 543 exonuclease activity for proof reading. 