DNA Repair Practice Problems

Which of the following DNA repair mechanisms reduces the final error rate if some incorrect nucleotides escape the proofreading process and prevent base substitution mutation?

Which of the following DNA repair mechanisms lacks the ability to proofread and can cause DNA sequence errors?

Which of the following enzymes in Drosophila binds to thymine dimers produced by UV irradiation and uses visible light energy to break the bonds forming the dimer?

In nucleotide excision repair, which of the following enzymes binds to the distorted DNA structure and uses its ATPase activity to unwind the DNA, forming a bubble around the damaged region and thereby allowing the DNA-cutting enzymes to excise it?

Which of the following DNA repair mechanisms in E. coli uses the enzyme photolyase to break the pyrimidine dimerization-induced bonds?

Which of the following statements based on the non-homologous end joining (NHEJ) pathway in E.coli is incorrect?

Which of the following enzymes ensures that the correct nucleotide is added to the expanding DNA strand by immediately removing the incorrect nucleotides?

Which of the following functions of DNA polymerase enzyme helps prevent errors during replication?

Sometimes nitrogenous bases that are methylated form H-bonds with the wrong nucleotide. This could be fixed by an enzyme by removing the methyl group from the nitrogenous base through demethylation. This is an example of:

The purpose of mismatch repair, which takes place immediately following the creation of new DNA, is to remove and replace mispaired bases that were not fixed during proofreading. What is the role of DNA ligase in mismatch repair?

________ prevents viral gene transcription and replication, acting as an antiviral defensive mechanism.

The ________ is a universal reaction to DNA damage in which DNA repair and mutagenesis are stimulated while the cell cycle is halted.

"_______" is a mechanism that corrects DNA that is replicating throughout the cell cycle, whereas "_______"is a pathway that corrects DNA that is continuously being damaged by UV radiation, radiation, and mutagens

What specific enzyme necessary for DNA repair is encoded by the dinB gene?

DNA polymerase III proofreads and corrects DNA replication errors through the exonuclease activity. DNA polymerase III consists of three subunits. Which of the following genes encodes the ɑ subunit?

The type of DNA repair in which the DNA glycosylase identifies and removes the mutated base from the DNA helix is referred to as:

Telomeres contain long repetitive sequences which protect the coding sequences from degradation during DNA replication. In every cell division, the telomere length decreases. What happens to the cell once the telomere reaches the critical length?

Maintaining the integrity of the genome is achieved through the well-known cellular defense process known as:

All of the following are the agents responsible for exogenous DNA damage, EXCEPT:

Any alteration to DNA that alters its coding characteristics or prevents it from performing normally during transcription or replication is referred to as: