Question 1

Eukaryotes need more types of DNA polymerases than bacteria because

Accepted Answer

A)  the DNA-containing organelles have their own DNA polymerases. 
B)  they have linear DNA , which is harder to replicate than circular DNA. 
C)  because they have more kinds of bases in their DNA than the four used by prokaryotes. 
D)  That's not true; eukaryotes do not have more types of DNA polymerases. 
A)  the DNA-containing organelles have their own DNA polymerases. 
B)  they have linear DNA , which is harder to replicate than circular DNA. 
C)  because they have more kinds of bases in their DNA than the four used by prokaryotes. 
D)  That's not true; eukaryotes do not have more types of DNA polymerases.

Question 2

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 3

One of the most important ways in which DNA is modified after synthesis is

Accepted Answer

A)  methylation of bases 
B)  covalent binding of proteins to the sugar moieties 
C)  splicing of RNA "leaders" 
D)  electrostatic binding of negatively charged counterions 
A)  methylation of bases 
B)  covalent binding of proteins to the sugar moieties 
C)  splicing of RNA "leaders" 
D)  electrostatic binding of negatively charged counterions

Question 4

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 5

Which of the following is a characteristic of eukaryotic, but not prokaryotic, DNA replication?

Accepted Answer

A)  Topoisomerases are required. 
B)  A primer is needed on the lagging strand only. 
C)  Histone biosynthesis must take place. 
D)  There is only one origin of replication. 
A)  Topoisomerases are required. 
B)  A primer is needed on the lagging strand only. 
C)  Histone biosynthesis must take place. 
D)  There is only one origin of replication.

Question 6

The flow of genetic information is RNA → DNA in

Accepted Answer

A)  all organisms. 
B)  all prokaryotes. 
C)  retroviruses. 
D)  no known organisms. 
A)  all organisms. 
B)  all prokaryotes. 
C)  retroviruses. 
D)  no known organisms.

Question 7

One major difficulty in replicating linear DNA molecules is replacing the segment of DNA occupied by the RNA primer on the telomeres at the ends of the DNA.

Accepted Answer

A) True 
 B)False

Question 8

The direction of synthesis of a DNA strand is

Accepted Answer

A)  from the 5' end to the 3' end on both strands. 
B)  from the 3' end to the 5' end on both strands. 
C)  from the 5' end to the 3' end on one strand and from the 3' end to the 5' end on the other strand. 
D)  none of the above. 
A)  from the 5' end to the 3' end on both strands. 
B)  from the 3' end to the 5' end on both strands. 
C)  from the 5' end to the 3' end on one strand and from the 3' end to the 5' end on the other strand. 
D)  none of the above.

Question 9

Since DNA Polymerase II has endonuclease activity, it is able to proofread its product when it is used in DNA repair.

Accepted Answer

A) True 
 B)False

Question 10

In the synthesis of DNA in Escherichia coli

Accepted Answer

A)  a single-strand nick in the template DNA gives rise to a swivel point just in advance of the replication fork 
B)  Mn2+ is required 
C)  all enzymes involved are single polypeptide chains 
D)  neither the template DNA nor the daughter DNA molecules exhibit supercoiling 
A)  a single-strand nick in the template DNA gives rise to a swivel point just in advance of the replication fork 
B)  Mn2+ is required 
C)  all enzymes involved are single polypeptide chains 
D)  neither the template DNA nor the daughter DNA molecules exhibit supercoiling

Question 11

It is so important to keep the DNA molecule fully connected that some repair mechanisms will actually allow mismatches or deletions from the DNA.

Accepted Answer

A) True 
 B)False

Question 12

Suppose Meselson & Stahl had observed the following data in their famous experiment involving a switch from medium containing 15N to 14N. What would they have concluded about the nature of DNA replication?

Accepted Answer

A)  They still would have concluded that DNA replication is semiconservative, i.e., each double helix contains one parental strand and one newly synthesized strand. 
B)  They would have concluded that DNA replication is conservative, i.e., one double helix contains only the parental strands, while the other contains only newly synthesized DNA. 
C)  They would have concluded that DNA replication is dispersive\random, i.e., each strand of each double helix contains a mixture of parental and newly synthesized sequences. 
D)  They would have been unable to distinguish which is correct. 
A)  They still would have concluded that DNA replication is semiconservative, i.e., each double helix contains one parental strand and one newly synthesized strand. 
B)  They would have concluded that DNA replication is conservative, i.e., one double helix contains only the parental strands, while the other contains only newly synthesized DNA. 
C)  They would have concluded that DNA replication is dispersive\random, i.e., each strand of each double helix contains a mixture of parental and newly synthesized sequences. 
D)  They would have been unable to distinguish which is correct.

Question 13

What is the requirement for a template strand in DNA replication?

Accepted Answer

A)  It serves as a guide in determining the next nucleotide to be added according to the Watson-Crick base pairing scheme. 
B)  It serves as the start point for the new DNA strand. 
C)  It allows the DNA polymerase to move along it easily. 
D)  It is a substrate for the 3' − 5' exonuclease activity. 
A)  It serves as a guide in determining the next nucleotide to be added according to the Watson-Crick base pairing scheme. 
B)  It serves as the start point for the new DNA strand. 
C)  It allows the DNA polymerase to move along it easily. 
D)  It is a substrate for the 3' − 5' exonuclease activity.

Question 14

Which of the following describes a difference between DNA polymerases in eukaryotes and bacteria?

Accepted Answer

A)  Some eukaryotic polymerases include a primase. 
B)  All the eukaryotic enzymes are polymeric. 
C)  Eukaryotes require a special enzyme to remove the RNA primer. 
D)  Some eukaryotic polymerases include a primase and all are polymeric. 
E)  All of these are correct. 
A)  Some eukaryotic polymerases include a primase. 
B)  All the eukaryotic enzymes are polymeric. 
C)  Eukaryotes require a special enzyme to remove the RNA primer. 
D)  Some eukaryotic polymerases include a primase and all are polymeric. 
E)  All of these are correct.

Question 15

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 16

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

Accepted Answer

A) True 
 B)False

Question 17

​ _____ is an enzyme that introduces supercoiling into closed circular DNA.

Accepted Answer

A)  Primase 
B)  DNA ligase 
C)  Helicase 
D)  DNA gyrase 
A)  Primase 
B)  DNA ligase 
C)  Helicase 
D)  DNA gyrase

Question 18

Linear eukaryotic DNA molecules

Accepted Answer

A)  have many origins of synthesis, while circular bacterial DNA usually have only one. 
B)  have only one origin of synthesis, while circular bacterial DNA usually have many. 
C)  are synthesized fully conservatively, while circular bacterial DNA is synthesized semi-conservatively. 
D)  are synthesized dispersively, while circular bacterial DNA is synthesized semi-conservatively. 
A)  have many origins of synthesis, while circular bacterial DNA usually have only one. 
B)  have only one origin of synthesis, while circular bacterial DNA usually have many. 
C)  are synthesized fully conservatively, while circular bacterial DNA is synthesized semi-conservatively. 
D)  are synthesized dispersively, while circular bacterial DNA is synthesized semi-conservatively.

Question 19

Which repair mechanism has an intermediate wherein a region of single-stranded DNA is temporarily created?

Accepted Answer

A)  Base Excision 
B)  Nucleotide Excision 
C)  Pol III Proofreading 
D)  Mismatch Repair 
A)  Base Excision 
B)  Nucleotide Excision 
C)  Pol III Proofreading 
D)  Mismatch Repair

Question 20

Telomerase activity may decline with old age and this could explain why cells lose their ability to divide after many replications.

Accepted Answer

A) True 
 B)False

Exam 10: Biosynthesis of Nucleic Acids Replication

Eukaryotes need more types of DNA polymerases than bacteria because

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

One of the most important ways in which DNA is modified after synthesis is

The enzyme telomerase uses mechanisms that involve:

Which of the following is a characteristic of eukaryotic, but not prokaryotic, DNA replication?

The flow of genetic information is RNA → DNA in

One major difficulty in replicating linear DNA molecules is replacing the segment of DNA occupied by the RNA primer on the telomeres at the ends of the DNA.

The direction of synthesis of a DNA strand is

Since DNA Polymerase II has endonuclease activity, it is able to proofread its product when it is used in DNA repair.

In the synthesis of DNA in Escherichia coli

It is so important to keep the DNA molecule fully connected that some repair mechanisms will actually allow mismatches or deletions from the DNA.

Suppose Meselson & Stahl had observed the following data in their famous experiment involving a switch from medium containing 15N to 14N. What would they have concluded about the nature of DNA replication?

What is the requirement for a template strand in DNA replication?

Which of the following describes a difference between DNA polymerases in eukaryotes and bacteria?

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

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

​ _____ is an enzyme that introduces supercoiling into closed circular DNA.

Linear eukaryotic DNA molecules

Which repair mechanism has an intermediate wherein a region of single-stranded DNA is temporarily created?

Telomerase activity may decline with old age and this could explain why cells lose their ability to divide after many replications.

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 the 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

Filters

Suppose Meselson & Stahl had observed the following data in their famous experiment involving a switch from medium containing ¹⁵N to ¹⁴N. What would they have concluded about the nature of DNA replication?

_____ is an enzyme that introduces supercoiling into closed circular DNA.