Describe why there are very few mistakes apparent after DNA

Describe why there are very few mistakes apparent after DNA synthesis has occurred (high fidelity)?

Solution

High fidelity means accurate replication of template strand which involves sequence of events starting from proper indentification and inserting correct nucleoside triphosphate at 3\' primer end. This exact synthesis of DNA is ensured by DNA polymerase enzyme which has significance binding preference to correct and incorrect nucleotide.The preferential activity is characterised by increase in lag time when incorrect nucleotide binds due to changed structure which ensures dissociation of incorrect nucleotide before polymerase progress.This is done by moving growing 3\' end of DNA to 3\'_5\' end of exonuclease to ensure proofreading and hence very few mistakes are apparent after DNA synthesis .