DNA Replication And Repair

This is an MCQ-based quiz for GRE on the topic of DNA Replication And Repair.

This includes base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR), and non-homologous end-joining (NHEJ).

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Which enzyme is responsible for removing the RNA primers added during DNA replication?

DNA polymerase I DNA ligase Primase DNA polymerase III

Magnesium is a necessary component of DNA polymerization, but is not found in the DNA molecule. What is the purpose of magnesium in the polymerization of DNA?

It is a cofactor for DNA polymerase III None of these answers are correct It binds to the two leaving groups during the DNA polymerization reaction It binds nucleotides in the cytosol and helps import them into the nucleus

What 3" functional group must be free in order to add the next nucleotide during DNA synthesis?

Carboxylic acid Hydroxyl Amine Phosphate

A select mutation is causing a cell lineage to be unable to replicate DNA successfully. When observed under a microscope, researchers observe that the DNA is able to be separated, but the template strands keep coming back together before the new strands can be replicated. Based on this observation, which protein involved in DNA replication is most likely mutated?

DNA helicase DNA primase Single-stranded binding protein DNA polymerase

Upon double-stranded DNA break, the cell can search the genome for a homologous sequence to serve as a template for repairing the damaged sequence. What is this process known as?

Non-homologous end joining Directed reversal Base excision repair Homology directed repair Crossing over

Which of the following is not true of DNA repair?

p53 is a protein responsible for activating many DNA repair pathways DNA repair cannot occur during replication Several DNA polymerases contain an exonuclease function Irreparable DNA damage may activate pathways that lead to apoptosis

Which prokaryotic polymerase is primarily responsible for filling in DNA nucleotides into the gap created by the removal of RNA primers?

DNA polymerase II DNA polymerase III RNA polymerase Reverse transcriptase DNA polymerase I

Which of the following is not true of DNA replication?

The lagging strand is synthesized in short fragments, directed away from the replication fork Replication occurs during prophase of mitosis Replication occurs in the 5' to 3' direction The DNA must be denatured at the replication fork

Which of the following enzymes is responsible for catalyzing the formation of phosphodiester bonds in single- and double-stranded DNA breaks?

Endonuclease DNA polymerase III DNA polymerase I DNA ligase Exonuclease

During DNA replication, single-stranded DNA is kept from reannealing due to the function of __________.

Helicase

Single-strand binding proteins

DNA topoisomerase

Histones

Quiz/Test Summary

Title: DNA Replication And Repair

Questions: 10

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