Question 1

Which of the following explains how the termination of DNA replication in E.coli occurs?

Accepted Answer

A) Tag protein binds the oriC locus on the DNA and acts as a helicase. 
B) Ter protein binds the tag locus on the DNA and acts as a polymerase. 
C) DnaC protein binds the DnaG locus on the DNA and acts as a gyrase. 
D) Tus protein binds the Ter locus on the DNA and acts as contrahelicase. 
A) Tag protein binds the oriC locus on the DNA and acts as a helicase. 
B) Ter protein binds the tag locus on the DNA and acts as a polymerase. 
C) DnaC protein binds the DnaG locus on the DNA and acts as a gyrase. 
D) Tus protein binds the Ter locus on the DNA and acts as contrahelicase. D

Question 2

Which of the following enzymes removes the RNA primer from the Okazaki fragment?

Accepted Answer

A) DNA polymerase I 
B) DNA ligase 
C) DNA polymerase III 
D) DNA gyrase 
A) DNA polymerase I 
B) DNA ligase 
C) DNA polymerase III 
D) DNA gyrase A

Question 3

UV light promotes the formation of covalent bonds between nearby thymine residues in a DNA strand.Which of the following structures is created as a result of this?

Accepted Answer

A) a cyclobutyl ring called a thymidine trimer 
B) a cyclohexyl ring called a thymidine trimer 
C) a cyclobutyl ring called a thymidine dimer 
D) a cyclohexyl ring called a thymidine dimer 
A) a cyclobutyl ring called a thymidine trimer 
B) a cyclohexyl ring called a thymidine trimer 
C) a cyclobutyl ring called a thymidine dimer 
D) a cyclohexyl ring called a thymidine dimer C

Question 4

Which of the following is NOT a part of homologous recombination?

Accepted Answer

A) ligation 
B) nicking 
C) EW or NS cleavage,resolution and re-ligation 
D) strand division 
A) ligation 
B) nicking 
C) EW or NS cleavage,resolution and re-ligation 
D) strand division

Question 5

Which of the following nucleotides would replace A in a transition mutation?

Accepted Answer

A) T 
B) C 
C) U 
D) G 
A) T 
B) C 
C) U 
D) G

Question 6

Which of the following defines SSBs?

Accepted Answer

A) supercoil stabilizing bodies 
B) single-stranded bodies called Okazaki fragments 
C) nucleases that hydrolyze single-stranded RNA primers 
D) single-stranded DNA-binding proteins that prevent re-annealing 
A) supercoil stabilizing bodies 
B) single-stranded bodies called Okazaki fragments 
C) nucleases that hydrolyze single-stranded RNA primers 
D) single-stranded DNA-binding proteins that prevent re-annealing

Question 7

Which of the following is the principal DNA polymerase in eukaryotic leading-strand DNA replication?

Accepted Answer

A) DNA polymerase α (alpha) 
B) DNA polymerase β (beta) 
C) DNA polymerase γ(gamma) 
D) DNA polymerase δ (delta) 
A) DNA polymerase α (alpha) 
B) DNA polymerase β (beta) 
C) DNA polymerase γ(gamma) 
D) DNA polymerase δ (delta)

Question 8

Which of the following is NOT a part of the prereplication complex (pre-RC)in the initiation of replication in yeast?

Accepted Answer

A) MCM complex 
B) CDKs 
C) Cdc6p 
D) ORC 
A) MCM complex 
B) CDKs 
C) Cdc6p 
D) ORC

Question 9

AZT (3'-azido-2',3'-dideoxythymidine)is a drug that gets incorporated into growing viral DNA.What enzyme activity does it block?

Accepted Answer

A) reverse transcriptase 
B) DNA ligase 
C) DNA polymerase β (beta) 
D) DNA polymerase α(alpha) 
A) reverse transcriptase 
B) DNA ligase 
C) DNA polymerase β (beta) 
D) DNA polymerase α(alpha)

Question 10

Which of the following protein kinases acts on the prereplication complex (pre-RC)to trigger DNA replication in eukaryotic cells?

Accepted Answer

A) ORC 
B) MCM 
C) cyclin B-CDK 
D) PKA 
A) ORC 
B) MCM 
C) cyclin B-CDK 
D) PKA

Question 11

Which of the following is a shared characteristic of DNA polymerases?

Accepted Answer

A) They are strongly processive. 
B) Incoming bases are paired with corresponding bases on the complementary strand within the polymerase active site. 
C) Polymerization proceeds in a 3'5' direction. 
D) Polymerization is antiparallel to template strand. 
A) They are strongly processive. 
B) Incoming bases are paired with corresponding bases on the complementary strand within the polymerase active site. 
C) Polymerization proceeds in a 3'5' direction. 
D) Polymerization is antiparallel to template strand.

Question 12

The repair of cyclobutane pyrimidine dimers involves bacterial photolyase.Which of the following cofactors does it use?

Accepted Answer

A) flavin and pterin 
B) S-adenosylmethionine and ATP 
C) CoA and CoQ 
D) flavin and TPP 
A) flavin and pterin 
B) S-adenosylmethionine and ATP 
C) CoA and CoQ 
D) flavin and TPP

Question 13

Which of the following regarding DNA gyrase in E.Coli is correct?

Accepted Answer

A) It works to remove negative supercoiling introduced by the DnaB protein (helicase). 
B) It is a topoisomerase that hydrolyzes ATP during its reaction mechanism. 
C) Its mechanism involves the breaking of a single phosphoester bond in 1 strand of dsDNA. 
D) It works to introduce positive supercoiling in DNA to overcome the torsion stress imposed upon unwinding. 
A) It works to remove negative supercoiling introduced by the DnaB protein (helicase). 
B) It is a topoisomerase that hydrolyzes ATP during its reaction mechanism. 
C) Its mechanism involves the breaking of a single phosphoester bond in 1 strand of dsDNA. 
D) It works to introduce positive supercoiling in DNA to overcome the torsion stress imposed upon unwinding.

Question 14

Which of the following is an RNA-dependent DNA polymerase that carries the RNA template with it to synthesize repeats at the 3'-ends of chromosomes?

Accepted Answer

A) DNA ligase 
B) telomerase 
C) topoisomerase 
D) DNA polymerase β (beta) 
A) DNA ligase 
B) telomerase 
C) topoisomerase 
D) DNA polymerase β (beta)

Question 15

Which protein moves along dsDNA using ATP-dependent helicase and nuclease activity during general recombination in E.coli?

Accepted Answer

A) RecBCD complex 
B) RuvB 
C) DNA polymerase I 
D) DNA ligase 
A) RecBCD complex 
B) RuvB 
C) DNA polymerase I 
D) DNA ligase

Question 16

Which of the following is NOT a characteristic of retroviruses?

Accepted Answer

A) They use viral DNA as a template. 
B) They must replicate through double-stranded DNA. 
C) The retroviral RNA is reverse transcribed to dsDNA,which must be inserted into the host genome. 
D) Their genome can lie dormant for years as a provirus in the host chromosome. 
A) They use viral DNA as a template. 
B) They must replicate through double-stranded DNA. 
C) The retroviral RNA is reverse transcribed to dsDNA,which must be inserted into the host genome. 
D) Their genome can lie dormant for years as a provirus in the host chromosome.

Question 17

Which of the following terms defines the exchange of one base for another?

Accepted Answer

A) frameshift mutation 
B) point mutation 
C) transition mutation 
D) transversion mutation 
A) frameshift mutation 
B) point mutation 
C) transition mutation 
D) transversion mutation

Question 18

Which of the following is NOT a common form of DNA damage?

Accepted Answer

A) replication errors resulting in a missing or incorrect base 
B) transcription errors resulting in the substitution of bases 
C) UV-induced base alterations,such as pyrimidine dimers 
D) strand breaks at phosphodiester bonds or within deoxyribose rings 
A) replication errors resulting in a missing or incorrect base 
B) transcription errors resulting in the substitution of bases 
C) UV-induced base alterations,such as pyrimidine dimers 
D) strand breaks at phosphodiester bonds or within deoxyribose rings

Question 19

Which of the following is NOT involved with RuvA,RuvB,and RuvC?

Accepted Answer

A) processing Holliday junctions into recombination products 
B) aiding strand invasions of the 3'-ssDNA into homologous DNA duplexes 
C) Holliday junction-specific helicase complex 
D) dissociating the RecA filament and catalyzing branch migration 
A) processing Holliday junctions into recombination products 
B) aiding strand invasions of the 3'-ssDNA into homologous DNA duplexes 
C) Holliday junction-specific helicase complex 
D) dissociating the RecA filament and catalyzing branch migration

Question 20

Which of the following does NOT cause mutations in DNA?

Accepted Answer

A) errors in replication 
B) physical insults on the cell,such as UV light 
C) errors in transcription 
D) chemical exposure 
A) errors in replication 
B) physical insults on the cell,such as UV light 
C) errors in transcription 
D) chemical exposure

Exam 28: DNA Metabolism: Replication, recombination, and Repair

Which of the following explains how the termination of DNA replication in E.coli occurs?

Which of the following enzymes removes the RNA primer from the Okazaki fragment?

UV light promotes the formation of covalent bonds between nearby thymine residues in a DNA strand.Which of the following structures is created as a result of this?

Which of the following is NOT a part of homologous recombination?

Which of the following nucleotides would replace A in a transition mutation?

Which of the following defines SSBs?

Which of the following is the principal DNA polymerase in eukaryotic leading-strand DNA replication?

Which of the following is NOT a part of the prereplication complex (pre-RC)in the initiation of replication in yeast?

AZT (3'-azido-2',3'-dideoxythymidine)is a drug that gets incorporated into growing viral DNA.What enzyme activity does it block?

Which of the following protein kinases acts on the prereplication complex (pre-RC)to trigger DNA replication in eukaryotic cells?

Which of the following is a shared characteristic of DNA polymerases?

The repair of cyclobutane pyrimidine dimers involves bacterial photolyase.Which of the following cofactors does it use?

Which of the following regarding DNA gyrase in E.Coli is correct?

Which of the following is an RNA-dependent DNA polymerase that carries the RNA template with it to synthesize repeats at the 3'-ends of chromosomes?

Which protein moves along dsDNA using ATP-dependent helicase and nuclease activity during general recombination in E.coli?

Which of the following is NOT a characteristic of retroviruses?

Which of the following terms defines the exchange of one base for another?

Which of the following is NOT a common form of DNA damage?

Which of the following is NOT involved with RuvA,RuvB,and RuvC?

Which of the following does NOT cause mutations in DNA?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Lipid Biosynthesis

Membranes and Membrane Transport

The Reception and Transmission of Extracellular Information

Enzymes Kinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Nutrition and the Organization of Metabolism

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Nitrogen Acquisition and Amino Acid Metabolism

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Synthesis and Degradation of Nucleotides

Recombinant Dna: Cloning and Creation of Chimeric Genes

Transcription and the Regulation of Gene Expression

Protein Synthesis

Post-Transcriptional Regulation of Gene Expression

Completing the Protein Life Cycle: Folding, processing, and Degradation

Metabolic Integration and Organ Specialization

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