Teaching MPPSC Assistant Professor Mock Test Series 2025 Life Sciences Fundamental Processes DNA replication, repair and recombination
DNA replication requires DNA Topoisomerase to remove the supercoiling of DNA that accumulates at the end of a growing replication fork. You wish to perform a PCR amplification of a gene that has been provided to you in a 6 kb plasmid vector. Why will you NOT use topoisomerase in your PCR reaction mix?
1
Taq polymerase has innate topoisomerase activity
2
Denaturation step in the PCR protocol precludes formation of supercoils
3
Reaction buffer has a pH that denatures DNA and avoids supercoiling
4
The 5´→ 3´ exonuclease activity of Taq polymerase does not allow supercoiling