Chapter 25, Problem 16P

$\left(\text{a}\right)$

Summary Introduction

To determine: The nucleotide sequence $\text{AAC}\left({\text{O}}^{\text{6}}\text{-meG}\right)\text{TGCAC}$ which is methylated at guanine residue with change of this sequence when replication occurs before repair.

Introduction:

Direct repair includes the removal of the formation of thymidine dimers when ultra-violet light is used. This reaction is catalyzed by enzyme $\text{DNA photolyase}$. Methylation of guanine residues takes place in the presence of methylating agents.

$\left(\text{b}\right)$

Summary Introduction

To determine: The nucleotide sequence $\text{AAC}\left({\text{O}}^{\text{6}}\text{-meG}\right)\text{TGCAC}$ which is methylated at guanine residue with change of this sequence when replication occurs after repair.

Introduction:

Methylation of guanine takes place after addition of chemical which leads to $\text{DNA}$ damage.

$\left(\text{c}\right)$

Summary Introduction

To determine: The nucleotide sequence $\text{AAC}\left({\text{O}}^{\text{6}}\text{-meG}\right)\text{TGCAC}$ which is methylated at guanine residue with two rounds of replication following repair.

Introduction:

Replication process leads to the formation of two strands of $\text{DNA}$ which have complementary base pairs present in between them.