Question

 

The engineered mutation should be in both strands, in order to maintain that mutation. If we insert a mismatch, the mutated strand will be newly syntheised one. Non-mutated strand will be the parental one. Systems evolved DNA methylation mechanisms to decrease such errors. Dam methylase is the best example for that. It methylates all GATC sequences in bacteria. If we take out bacterial parental DNA and engineer it with mismatch, parental strand will be methylated one and new strand will not be methylated. DNA repair system identifies parental strand based GATC methylation, removes mismatched bases from new strand and replaces with normal bases. This happens well before replication. So equal mixture of parental and mutated genome is not expected. Mismatch repair, goes according to parental strand and always decreases the frequency of mutations.

Answer 1

TEXT BEFORE :

the engineered mutation should be in both strands, in order to maintain that mutation. If we insert a mismatch, the mutated strand will be newly syntheised one. Non-mutated strand will be the parental one. Systems evolved DNA methylation mechanisms to decrease such errors. Dam methylase is the best example for that. It methylates all GATC sequences in bacteria. If we take out bacterial parental DNA and engineer it with mismatch, parental strand will be methylated one and new strand will not be methylated. DNA repair system identifies parental strand based GATC methylation, removes mismatched bases from new strand and replaces with normal bases. This happens well before replication. So equal mixture of parental and mutated genome is not expected. Mismatch repair, goes according to parental strand and always decreases the frequency of mutations.


TEXT AFTER PARAPHRASE :

the engineered mutation should be in each strands, so that it will preserve that mutation. If we insert a mismatch, the mutated strand might be newly syntheised one. Non-mutated strand may be the parental one. systems advanced DNA methylation mechanisms to lower such errors. Dam methylase is the exceptional example for that. It methylates all GATC sequences in micro organism. If we take out bacterial parental DNA and engineer it with mismatch, parental strand might be methylated one and new strand will now not be methylated. DNA repair system identifies parental strand based totally GATC methylation, gets rid of mismatched bases from new strand and replaces with everyday bases. This takes place nicely before replication. So equal combination of parental and mutated genome isn't predicted. Mismatch repair, is going in line with parental strand and constantly decreases the frequency of mutations.

MEANING OF TEXT SO THAT YOU CLEAR WITH YOUR TEXT :

If we want mutation to occur then it should be in both strands because DNA methylation process to decrease errors occurring due to mutations before replication process. For example, DAM methylase, which is an enzyme that adds a methyl group to the adenine of the sequence 5'-GATC-3' in newly synthesized DNA. So after DNA synthesis, the daughter strand is unmethylated. Dam therefore, mark old DNA as old DNA is methylated new DNA will not.

In cases of base mismatch in the double helix, it’s likely that new DNA was put incorrectly, so cellular machinery will use old DNA which is methylated strand to guide and make correct strand using complementary base pairing.

This occurs before replication and mismatch repair decreases the frequency of mutations....