Answer to Question #165675 in Genetics for Virat

Question

4) When so much damage occurs in DNA that during excision reparation the cell does not have time to

completely eliminate them. As a result, after replication of this DNA the daughter chain has “gaps” that are

formed at the site of damage of the mother DNA chain,.

1. What type of reparation corrects such damage?

2. What are the molecular mechanisms the cause of this disorder?

3. Feature of postreplication reparation.

4. What other types of postreplication reparation do you know, describe.

Answer 1

Recombination repair or otherwise known as retrieval system is a mechanism in which misincorperated or damaged nucleotides are cut out of the growing strand such that a lesion is created, the final remaining strand is used as a template for synthesis a complimentary strand often past the lesion leaving a gap at the lesion site. RecA mediated recombination is the method involved in the bringing a single strand of DNA using information from the normal daughter strand.

Other methods of DNA repair include;

Base excision repair, a mechanism that recognizes and repair damaged DNA are; that do not have significant distortion go the helical DNA structure.

Mismatch repair, used to repair errors as a result of DNA synthesis by recognizing, excising misincoroperated nucleotides and replacing them with the correct ones.