Question 1

Which of the following is not a function of DNA polymerase I from E. coli?

Accepted Answer

A)  adding nucleotides to the primer strand 
B)  3' → 5' exonuclease activity 
C)  5' → 3' exonuclease activity 
D)  proofreading 
A)  adding nucleotides to the primer strand 
B)  3' → 5' exonuclease activity 
C)  5' → 3' exonuclease activity 
D)  proofreading

Question 2

In eukaryotic replication, the RNA primers are degraded by:

Accepted Answer

A)  the 5' to 3' exonuclease activity of pol ä 
B)  DNA ligase 
C)  Helicase 
D)  FEN-1 and RNase H1 
A)  the 5' to 3' exonuclease activity of pol ä 
B)  DNA ligase 
C)  Helicase 
D)  FEN-1 and RNase H1

Question 3

The energetic driving force for nucleic acid synthesis is

Accepted Answer

A)  removal of pyrophosphate from the incoming nucleotide. 
B)  removal of pyrophosphate from the growing strand. 
C)  removal of inorganic phosphate from the incoming nucleotide. 
D)  removal of inorganic phosphate from the growing strand. 
A)  removal of pyrophosphate from the incoming nucleotide. 
B)  removal of pyrophosphate from the growing strand. 
C)  removal of inorganic phosphate from the incoming nucleotide. 
D)  removal of inorganic phosphate from the growing strand.

Question 4

The universal features of DNA replication include all the following, except:

Accepted Answer

A)  Release of PPi from a nucleoside triphosphate. 
B)  Synthesis from the 5' end to the 3' end. 
C)  Base pairing of A to T and G to C. 
D)  Use of a primer. 
E)  All of these describe DNA synthesis. 
A)  Release of PPi from a nucleoside triphosphate. 
B)  Synthesis from the 5' end to the 3' end. 
C)  Base pairing of A to T and G to C. 
D)  Use of a primer. 
E)  All of these describe DNA synthesis.

Question 5

The mechanism of breakage and reunion of DNA strands during recombination was proposed by:

Accepted Answer

A)  Messelson and Stahl 
B)  Messelson and Weigle 
C)  Robin Holliday 
D)  Francis Crick 
A)  Messelson and Stahl 
B)  Messelson and Weigle 
C)  Robin Holliday 
D)  Francis Crick

Question 6

An important process in the synthesis of new DNA is

Accepted Answer

A)  proofreading and repair. 
B)  unwinding of the double helix. 
C)  protection of single-stranded regions from nuclease action. 
D)  all of these 
A)  proofreading and repair. 
B)  unwinding of the double helix. 
C)  protection of single-stranded regions from nuclease action. 
D)  all of these

Question 7

DNA repair mechanisms are essentially the same whether the DNA has minor damage or major damage.

Accepted Answer

A) True 
 B)False

Question 8

E. coli replication on the lagging strand

Accepted Answer

A)  is carried out by DNA polymerase I 
B)  is initially synthesized as Okazaki fragments 
C)  is synthesized continuously 
D)  has this DNA strand synthesized in a 3' → 5' direction 
A)  is carried out by DNA polymerase I 
B)  is initially synthesized as Okazaki fragments 
C)  is synthesized continuously 
D)  has this DNA strand synthesized in a 3' → 5' direction

Question 9

Both eukaryotes and prokaryotes use a dimeric DNA Polymerase for DNA replication.

Accepted Answer

A) True 
 B)False

Question 10

In the original Central Dogma of biology, the ordinary flow of genetic information is:

Accepted Answer

A)  DNA → RNA → Protein 
B)  RNA → DNA → Protein 
C)  Protein → RNA → DNA 
D)  DNA → Protein → RNA. 
E)  None of these 
A)  DNA → RNA → Protein 
B)  RNA → DNA → Protein 
C)  Protein → RNA → DNA 
D)  DNA → Protein → RNA. 
E)  None of these

Question 11

Which of the following is not required for optimal DNA replication?

Accepted Answer

A)  Primase 
B)  DNA Polymerase II. 
C)  Single strand binding proteins. 
D)  Gyrase 
E)  All of these are necessary. 
A)  Primase 
B)  DNA Polymerase II. 
C)  Single strand binding proteins. 
D)  Gyrase 
E)  All of these are necessary.

Question 12

Why is thymine used in DNA rather than uracil?

Accepted Answer

A)  Thymine is more hydrophobic, so it stacks better in the helix. 
B)  If cytosine is deaminated, it forms uracil, which can be easily distinguished from thymine. 
C)  Thymine is not capable of wobbling, so it pairs more accurately than uracil. 
D)  All of these are correct. 
A)  Thymine is more hydrophobic, so it stacks better in the helix. 
B)  If cytosine is deaminated, it forms uracil, which can be easily distinguished from thymine. 
C)  Thymine is not capable of wobbling, so it pairs more accurately than uracil. 
D)  All of these are correct.

Question 13

Which of the following activities does E. coli DNA polymerase III lack?

Accepted Answer

A)  5' → 3' polymerase 
B)  5' → 3' exonuclease 
C)  3' → 5' exonuclease 
D)  E. coli DNA polymerase III has ALL of the above activities. 
A)  5' → 3' polymerase 
B)  5' → 3' exonuclease 
C)  3' → 5' exonuclease 
D)  E. coli DNA polymerase III has ALL of the above activities.

Question 14

Which of the following statements is true about the so-called "MUT" (for "mutation") repair mechanisms?

Accepted Answer

A)  Depend on the methylation of old strands of DNA to determine which strand to repair. 
B)  Often remove hundreds or even thousands of bases during the repair process. 
C)  Can only repair mismatches that occur during the normal replication process. 
D)  All of these are true. 
A)  Depend on the methylation of old strands of DNA to determine which strand to repair. 
B)  Often remove hundreds or even thousands of bases during the repair process. 
C)  Can only repair mismatches that occur during the normal replication process. 
D)  All of these are true.

Question 15

Which of the following is not an activity of DNA Polymerase I?

Accepted Answer

A)  Polymerase activity. 
B)  Ability to nick intact double stranded DNA. 
C)  5' → 3' exonuclease. 
D)  3' → 5' exonuclease. 
E)  All of these are present in DNA Pol I. 
A)  Polymerase activity. 
B)  Ability to nick intact double stranded DNA. 
C)  5' → 3' exonuclease. 
D)  3' → 5' exonuclease. 
E)  All of these are present in DNA Pol I.

Question 16

Which is most likely to have a high processivity?

Accepted Answer

A)  a DNA polymerase that is primarily a repair enzyme 
B)  a primase 
C)  a DNA ligase 
D)  a DNA polymerase that is a main polymerizing enzyme 
A)  a DNA polymerase that is primarily a repair enzyme 
B)  a primase 
C)  a DNA ligase 
D)  a DNA polymerase that is a main polymerizing enzyme

Question 17

Single strand binding proteins are important for this activity:

Accepted Answer

A)  Prevent single-stranded DNA from rewinding. 
B)  Protect single-stranded DNA from enzymatic degradation. 
C)  Prevent double helical DNA from unwinding. 
D)  Prevent double helical DNA from becoming a triple helix. 
E)  Prevent single-stranded DNA from rewinding and protect it from degradation. 
A)  Prevent single-stranded DNA from rewinding. 
B)  Protect single-stranded DNA from enzymatic degradation. 
C)  Prevent double helical DNA from unwinding. 
D)  Prevent double helical DNA from becoming a triple helix. 
E)  Prevent single-stranded DNA from rewinding and protect it from degradation.

Question 18

The enzyme telomerase uses mechanisms that involve:

Accepted Answer

A)  Repeating sequences at the telomeres. 
B)  Having RNA oligonucleotides to act as templates as part of the enzyme. 
C)  Allowing the end of the chromosome to get a little shorter each time a cell divides. 
D)  Both repeating sequences at the end of chromosomes and RNA oligonucleotides to act as templates as part of the enzyme. 
E)  All of these. 
A)  Repeating sequences at the telomeres. 
B)  Having RNA oligonucleotides to act as templates as part of the enzyme. 
C)  Allowing the end of the chromosome to get a little shorter each time a cell divides. 
D)  Both repeating sequences at the end of chromosomes and RNA oligonucleotides to act as templates as part of the enzyme. 
E)  All of these.

Question 19

Which of the following characteristics is not associated with E. coli primase?

Accepted Answer

A)  it synthesizes the RNA primer in DNA replication 
B)  it synthesizes a primer with a free 3'−OH end 
C)  it is essential for DNA replication 
D)  it is essential for RNA replication 
A)  it synthesizes the RNA primer in DNA replication 
B)  it synthesizes a primer with a free 3'−OH end 
C)  it is essential for DNA replication 
D)  it is essential for RNA replication

Question 20

All the following describe the general mechanism of DNA synthesis, except:

Accepted Answer

A)  From the perspective of the DNA template strands, one strand is made 5' → 3' while the other strand is made 3' → 5'. 
B)  The strands become separated during synthesis. 
C)  Synthesis occurs in both directions from the starting site of synthesis. 
D)  Synthesis of DNA is a very accurate process. 
E)  All of these are correct. 
A)  From the perspective of the DNA template strands, one strand is made 5' → 3' while the other strand is made 3' → 5'. 
B)  The strands become separated during synthesis. 
C)  Synthesis occurs in both directions from the starting site of synthesis. 
D)  Synthesis of DNA is a very accurate process. 
E)  All of these are correct.

Exam 10: Biosynthesis of Nucleic Acids: Replication

Which of the following is not a function of DNA polymerase I from E. coli?

In eukaryotic replication, the RNA primers are degraded by:

The energetic driving force for nucleic acid synthesis is

The universal features of DNA replication include all the following, except:

The mechanism of breakage and reunion of DNA strands during recombination was proposed by:

An important process in the synthesis of new DNA is

DNA repair mechanisms are essentially the same whether the DNA has minor damage or major damage.

E. coli replication on the lagging strand

Both eukaryotes and prokaryotes use a dimeric DNA Polymerase for DNA replication.

In the original Central Dogma of biology, the ordinary flow of genetic information is:

Which of the following is not required for optimal DNA replication?

Why is thymine used in DNA rather than uracil?

Which of the following activities does E. coli DNA polymerase III lack?

Which of the following statements is true about the so-called "MUT" (for "mutation") repair mechanisms?

Which of the following is not an activity of DNA Polymerase I?

Which is most likely to have a high processivity?

Single strand binding proteins are important for this activity:

The enzyme telomerase uses mechanisms that involve:

Which of the following characteristics is not associated with E. coli primase?

All the following describe the general mechanism of DNA synthesis, except:

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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