Question 1

Xeroderma pigmentosa is a genetically inherited disorder in which the cells of patients are:

Accepted Answer

A)  unable to excise thymine dimers. 
B)  unable to ligate Okazaki fragments. 
C)  unable to remove RNA primers. 
D)  unable to fill gaps in DNA. 
E)  unable to relax supercoiling. 
A)  unable to excise thymine dimers. 
B)  unable to ligate Okazaki fragments. 
C)  unable to remove RNA primers. 
D)  unable to fill gaps in DNA. 
E)  unable to relax supercoiling.

Question 2

Which of the following is NOT an important player in DNA replication?

Accepted Answer

A)  primase 
B)  DNA polymerase I 
C)  DNA polymerase II 
D)  DNA ligase 
A)  primase 
B)  DNA polymerase I 
C)  DNA polymerase II 
D)  DNA ligase

Question 3

All of the following statements are TRUE EXCEPT

Accepted Answer

A)  excision repair requires a special ribonuclease. 
B)  DNA synthesis in bacteria requires RNA synthesis. 
C)  DNA polymerase I probably functions in excision repair. 
D)  RNA polymerase requires a template. 
E)  DNA synthesis in eukaryotes initiates at multiple sites. 
A)  excision repair requires a special ribonuclease. 
B)  DNA synthesis in bacteria requires RNA synthesis. 
C)  DNA polymerase I probably functions in excision repair. 
D)  RNA polymerase requires a template. 
E)  DNA synthesis in eukaryotes initiates at multiple sites.

Question 4

All of the following statements are true with regard to DNA replication EXCEPT which one?

Accepted Answer

A)  It involves a transient covalent link between RNA and DNA chains. 
B)  The over-all process is bidirectional. 
C)  Chain growth occurs by addition at the end of new strands. 
D)  The only nucleotides required are deoxynucleoside triphosphates. 
E)  Chain growth is discontinuous. 
A)  It involves a transient covalent link between RNA and DNA chains. 
B)  The over-all process is bidirectional. 
C)  Chain growth occurs by addition at the end of new strands. 
D)  The only nucleotides required are deoxynucleoside triphosphates. 
E)  Chain growth is discontinuous.

Question 5

Which of the following is NOT an important player in DNA replication?

Accepted Answer

A)  primase 
B)  DNA polymerase I 
C)  DNA polymerase II 
D)  DNA ligase 
A)  primase 
B)  DNA polymerase I 
C)  DNA polymerase II 
D)  DNA ligase

Question 6

Helicases

Accepted Answer

A)  cut one strand of the double helix. 
B)  cut both strands of the double helix. 
C)  require ATP. 
D)  unwind the double helix. 
E)  C and D 
A)  cut one strand of the double helix. 
B)  cut both strands of the double helix. 
C)  require ATP. 
D)  unwind the double helix. 
E)  C and D

Question 7

Okazaki fragments are associated with

Accepted Answer

A)  resolution of recombination intermediates. 
B)  splicing of transcripts. 
C)  resolution of DNA replication at telomeres. 
D)  replication of the leading strand. 
E)  replication of the lagging strand. 
A)  resolution of recombination intermediates. 
B)  splicing of transcripts. 
C)  resolution of DNA replication at telomeres. 
D)  replication of the leading strand. 
E)  replication of the lagging strand.

Question 8

Following oxidative deamination with nitrous acid and several rounds of replication, which of the following base pairs would you expect to replace the complementary base pair A-T?

Accepted Answer

A)  T-G 
B)  G-C 
C)  C-G 
D)  T-A 
E)  G-T 
A)  T-G 
B)  G-C 
C)  C-G 
D)  T-A 
E)  G-T

Question 9

The RNA prier in replication differs fro other RNA in that it

Accepted Answer

A)  contains T instead of U. 
B)  is formed by DNA polymerase I. 
C)  exists only as a DNA-RNA double-stranded hybrid. 
D)  contains a triphosphate group at the 5' end immediately after synthesis. 
E)  is synthesized in the --> 5' direction. 
A)  contains T instead of U. 
B)  is formed by DNA polymerase I. 
C)  exists only as a DNA-RNA double-stranded hybrid. 
D)  contains a triphosphate group at the 5' end immediately after synthesis. 
E)  is synthesized in the --> 5' direction.

Question 10

Which of the following enzymes is involved in extending the ends of linear chromosomal DNA?

Accepted Answer

A)  telomerase 
B)  ligase 
C)  primase 
D)  RNA polymerase 
E)  DNA polymerase 
A)  telomerase 
B)  ligase 
C)  primase 
D)  RNA polymerase 
E)  DNA polymerase

Question 11

Some frameshift mutations may be corrected by a

Accepted Answer

A)  transition. 
B)  transversion. 
C)  double deletion. 
D)  missense mutation. 
A)  transition. 
B)  transversion. 
C)  double deletion. 
D)  missense mutation.

Question 12

An alteration in the genetic material which eventually gives rise to mutant progeny may originate in which of the following?

Accepted Answer

A)  only the sense strand of the DNA 
B)  only the anti-sense strand of DNA 
C)  only both strands simultaneously 
D)  either strand of DNA 
E)  mRNA 
A)  only the sense strand of the DNA 
B)  only the anti-sense strand of DNA 
C)  only both strands simultaneously 
D)  either strand of DNA 
E)  mRNA

Question 13

Primase is an enzyme in the primosome. It is a

Accepted Answer

A)  DNA ligase. 
B)  RNA dependent DNA polymerase. 
C)  DNA dependent RNA polymerase. 
D)  RNA dependent RNA polymerase. 
E)  none of the above 
A)  DNA ligase. 
B)  RNA dependent DNA polymerase. 
C)  DNA dependent RNA polymerase. 
D)  RNA dependent RNA polymerase. 
E)  none of the above

Question 14

The rate of DNA replication in eukaryotic cell nuclei is primarily governed by

Accepted Answer

A)  the rate of elongation of DNA chains (i.e., number of nucleotides added per growing chain per second). 
B)  the number of replication forks per cell. 
C)  the activity of RNA polymerase III. 
D)  the number of chromosomes per cell. 
E)  None of the other answers is correct. 
A)  the rate of elongation of DNA chains (i.e., number of nucleotides added per growing chain per second). 
B)  the number of replication forks per cell. 
C)  the activity of RNA polymerase III. 
D)  the number of chromosomes per cell. 
E)  None of the other answers is correct.

Question 15

What is the function of the to 5' exonuclease activity of bacterial DNA polymerases?

Accepted Answer

A)  removes mismatched bases during replication 
B)  removes pyrimidine dimers 
C)  removes the RNA primers of Okazaki fragments 
D)  initiates mRNA synthesis 
E)  processes precursors of ribosomal RNA 
A)  removes mismatched bases during replication 
B)  removes pyrimidine dimers 
C)  removes the RNA primers of Okazaki fragments 
D)  initiates mRNA synthesis 
E)  processes precursors of ribosomal RNA

Question 16

Topoisomerase I

Accepted Answer

A)  unwinds double stranded DNA by breaking base pairs. 
B)  will decrease the writhing number of negatively supercoiled DNA. 
C)  will decrease the linking number of negatively supercoiled DNA. 
D)  nicks one strand of double stranded DNA. 
E)  cuts both strands of double stranded DNA. 
A)  unwinds double stranded DNA by breaking base pairs. 
B)  will decrease the writhing number of negatively supercoiled DNA. 
C)  will decrease the linking number of negatively supercoiled DNA. 
D)  nicks one strand of double stranded DNA. 
E)  cuts both strands of double stranded DNA.

Question 17

Each of the statements about DNA replication is true EXCEPT which one?

Accepted Answer

A)  DNA replication can be bidirectional. 
B)  DNA replication can be semiconservative. 
C)  DNA replication in humans involves RNA. 
D)  DNA replication requires only one protein, namely, DNA polymerase. 
A)  DNA replication can be bidirectional. 
B)  DNA replication can be semiconservative. 
C)  DNA replication in humans involves RNA. 
D)  DNA replication requires only one protein, namely, DNA polymerase.

Question 18

Which of the following enzymes has 5' exonuclease activity?

Accepted Answer

A)  Restriction enzymes 
B)  Topoisomerase I 
C)  Topoisomerase II 
D)  DNA polymerase I 
E)  DNA ligase 
A)  Restriction enzymes 
B)  Topoisomerase I 
C)  Topoisomerase II 
D)  DNA polymerase I 
E)  DNA ligase

Question 19

During the SOS response to DNA damage (as by UV light) which of the following is not true?

Accepted Answer

A)  RecA protein synthesis is increased. 
B)  The LexA protein is destroyed. 
C)  Synthesis of the LexA protein is increased. 
D)  The LexA repressor protein shuts down the house keeping genes. 
E)  The synthesis of SSB and the uvrABC complex proteins are increased. 
A)  RecA protein synthesis is increased. 
B)  The LexA protein is destroyed. 
C)  Synthesis of the LexA protein is increased. 
D)  The LexA repressor protein shuts down the house keeping genes. 
E)  The synthesis of SSB and the uvrABC complex proteins are increased.

Question 20

Ionizing radiation is capable of producing genetic mutations by

Accepted Answer

A)  base-changes in the DNA. 
B)  base-deletions in the DNA. 
C)  breaking chromosomes. 
D)  All of the above. 
E)  Only A and B above. 
A)  base-changes in the DNA. 
B)  base-deletions in the DNA. 
C)  breaking chromosomes. 
D)  All of the above. 
E)  Only A and B above.

Exam 4: DNA Replication, Recombination, and Repair

Xeroderma pigmentosa is a genetically inherited disorder in which the cells of patients are:

Which of the following is NOT an important player in DNA replication?

All of the following statements are TRUE EXCEPT

All of the following statements are true with regard to DNA replication EXCEPT which one?

Which of the following is NOT an important player in DNA replication?

Helicases

Okazaki fragments are associated with

Following oxidative deamination with nitrous acid and several rounds of replication, which of the following base pairs would you expect to replace the complementary base pair A-T?

The RNA prier in replication differs fro other RNA in that it

Which of the following enzymes is involved in extending the ends of linear chromosomal DNA?

Some frameshift mutations may be corrected by a

An alteration in the genetic material which eventually gives rise to mutant progeny may originate in which of the following?

Primase is an enzyme in the primosome. It is a

The rate of DNA replication in eukaryotic cell nuclei is primarily governed by

What is the function of the to 5' exonuclease activity of bacterial DNA polymerases?

Topoisomerase I

Each of the statements about DNA replication is true EXCEPT which one?

Which of the following enzymes has 5' exonuclease activity?

During the SOS response to DNA damage (as by UV light) which of the following is not true?

Ionizing radiation is capable of producing genetic mutations by

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

Protein I: Composition and Structure

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Protein II: Structure-Function Relationships in Protein Families

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

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