Question 1

Control of transcription in prokaryotes does not involve

Accepted Answer

A)  enhancers. 
B)  silencers. 
C)  leucine zipper proteins. 
D)  alternative σ factors. 
A)  enhancers. 
B)  silencers. 
C)  leucine zipper proteins. 
D)  alternative σ factors.

Question 2

Which of following statements concerning RNA transcription is false?

Accepted Answer

A)  The DNA strands become separated during synthesis. 
B)  Synthesis of RNA is as accurate as synthesis of DNA 
C)  The template strand is read in the 3' → 5' direction. 
D)  All 4 ribonucleotides are required. 
E)  A primer is required for RNA synthesis 
A)  The DNA strands become separated during synthesis. 
B)  Synthesis of RNA is as accurate as synthesis of DNA 
C)  The template strand is read in the 3' → 5' direction. 
D)  All 4 ribonucleotides are required. 
E)  A primer is required for RNA synthesis

Question 3

What is the need for a primer in transcription?

Accepted Answer

A)  It ensures the fidelity of the newly synthesized RNA strand. 
B)  There is none. 
C)  RNA polymerases requires a preexisting strand with a nucleotide having a 3'−OH. 
D)  RNA polymerase requires a preexisting strand with a nucleotide having a 5'−OH. 
A)  It ensures the fidelity of the newly synthesized RNA strand. 
B)  There is none. 
C)  RNA polymerases requires a preexisting strand with a nucleotide having a 3'−OH. 
D)  RNA polymerase requires a preexisting strand with a nucleotide having a 5'−OH.

Question 4

Where is the TATA box located?

Accepted Answer

A)  At the transcription start site (+1). 
B)  −10 region. 
C)  −25 region. 
D)  −40 region. 
A)  At the transcription start site (+1). 
B)  −10 region. 
C)  −25 region. 
D)  −40 region.

Question 5

Which category of ribozymes requires an external guanosine frothier action?

Accepted Answer

A)  Group I 
B)  Group II 
C)  Both Group I & Group II 
D)  Neither Group I nor Group II 
A)  Group I 
B)  Group II 
C)  Both Group I & Group II 
D)  Neither Group I nor Group II

Question 6

How do enhancers differ from promoters?

Accepted Answer

A)  Enhancers do not bind RNA polymerase. 
B)  Enhancers include the UP element. 
C)  Enhancers bind the sigma (σ) factor. 
D)  There is no difference; these terms are synonymous. 
A)  Enhancers do not bind RNA polymerase. 
B)  Enhancers include the UP element. 
C)  Enhancers bind the sigma (σ) factor. 
D)  There is no difference; these terms are synonymous.

Question 7

Alternative removal of exons from mRNA is important in which of the following?

Accepted Answer

A)  Troponins and other contractile proteins. 
B)  Different types of collagen. 
C)  The disease lupus. 
D)  Alzheimer's disease. 
E)  All of these. 
A)  Troponins and other contractile proteins. 
B)  Different types of collagen. 
C)  The disease lupus. 
D)  Alzheimer's disease. 
E)  All of these.

Question 8

Which of the following statements about eukaryotic and prokaryotic RNA polymerases, is false?

Accepted Answer

A)  There are 3 different RNA polymerases in eukaryotes, instead of just one. 
B)  Eukaryotic polymerases have the same number of subunits as prokaryotic ones. 
C)  Only prokaryotic polymerases use sigma factor. 
D)  The enzymatic mechanism is the same for both types of organisms. 
A)  There are 3 different RNA polymerases in eukaryotes, instead of just one. 
B)  Eukaryotic polymerases have the same number of subunits as prokaryotic ones. 
C)  Only prokaryotic polymerases use sigma factor. 
D)  The enzymatic mechanism is the same for both types of organisms.

Question 9

Post-transcription processing of mRNA in prokaryotes is required.

Accepted Answer

A) True 
 B)False

Question 10

The enzyme principally responsible for RNA synthesis in Escherichia coli

Accepted Answer

A)  is a multisubunit enzyme 
B)  consists of a single polypeptide chain 
C)  requires Mn2+ for activity 
D)  requires a DNA primer 
A)  is a multisubunit enzyme 
B)  consists of a single polypeptide chain 
C)  requires Mn2+ for activity 
D)  requires a DNA primer

Question 11

Which of the following is the best description of an operon?

Accepted Answer

A)  An enhancer that positively regulates gene expression. 
B)  An silencer that negatively regulates gene expression. 
C)  A binding element for the sigma (σ) factor. 
D)  A group of genes under the control of a common promoter. 
A)  An enhancer that positively regulates gene expression. 
B)  An silencer that negatively regulates gene expression. 
C)  A binding element for the sigma (σ) factor. 
D)  A group of genes under the control of a common promoter.

Question 12

All of the following apply to attenuation mechanisms, except:

Accepted Answer

A)  They are used most often for operons for amino acid synthesis. 
B)  They involve the synthesis of proteins in the regulation of RNA synthesis. 
C)  The rate of RNA synthesis is regulated by the conformation of the protein being synthesized. 
D)  They require the presence of partially completed mRNA molecules. 
E)  All of these apply to attenuation mechanisms. 
A)  They are used most often for operons for amino acid synthesis. 
B)  They involve the synthesis of proteins in the regulation of RNA synthesis. 
C)  The rate of RNA synthesis is regulated by the conformation of the protein being synthesized. 
D)  They require the presence of partially completed mRNA molecules. 
E)  All of these apply to attenuation mechanisms.

Question 13

A single operon

Accepted Answer

A)  usually contains all the enzymes which are specific for the synthesis of a special biomolecule. 
B)  usually does not contain all the enzymes which are specific for the synthesis of a special biomolecule. 
C)  usually contains only a single structural gene for a critical enzyme. 
D)  usually contains only a gene for a repressor. 
A)  usually contains all the enzymes which are specific for the synthesis of a special biomolecule. 
B)  usually does not contain all the enzymes which are specific for the synthesis of a special biomolecule. 
C)  usually contains only a single structural gene for a critical enzyme. 
D)  usually contains only a gene for a repressor.

Question 14

The elongation and termination phases of eukaryotic transcription

Accepted Answer

A)  require several protein factors 
B)  are better understood than the initiation phase 
C)  are not subject to control mechanisms, only the initiation phase 
D)  proceed at a constant rate and always stop at the same termination sequence 
A)  require several protein factors 
B)  are better understood than the initiation phase 
C)  are not subject to control mechanisms, only the initiation phase 
D)  proceed at a constant rate and always stop at the same termination sequence

Question 15

Consensus sequences are

Accepted Answer

A)  sequences that are invariant throughout the DNA. 
B)  sequences required for transcription to occur 
C)  sequences that have many bases in common 
D)  sequences that lie far upstream of the core promoter. 
A)  sequences that are invariant throughout the DNA. 
B)  sequences required for transcription to occur 
C)  sequences that have many bases in common 
D)  sequences that lie far upstream of the core promoter.

Question 16

The catabolite activator protein can overcome the effect of a repressor binding to the operon.

Accepted Answer

A) True 
 B)False

Question 17

What provides the energy for the conversion from the open complex to chain elongation?

Accepted Answer

A)  ATP hydrolysis distinct from any incorporation into the chain. 
B)  Nucleotide hydrolysis associated with incorporation into the chain. 
C)  Torsional stress built into the separating DNA strands. 
D)  Binding of rho (ρ) factor to the holoenzyme. 
E)  None of these 
A)  ATP hydrolysis distinct from any incorporation into the chain. 
B)  Nucleotide hydrolysis associated with incorporation into the chain. 
C)  Torsional stress built into the separating DNA strands. 
D)  Binding of rho (ρ) factor to the holoenzyme. 
E)  None of these

Question 18

Which is not associated with bacterial promoters?

Accepted Answer

A)  the transcription start site 
B)  the Pribnow box 
C)  the −35 element 
D)  3' antiterminator 
A)  the transcription start site 
B)  the Pribnow box 
C)  the −35 element 
D)  3' antiterminator

Question 19

The leucine zipper is different from other DNA binding domains, since it requires the DNA-binding protein to form a dimer.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following RNAs is noted for having a "cloverleaf" structure?

Accepted Answer

A)  mRNA 
B)  rRNA 
C)  tRNA 
D)  All of these 
A)  mRNA 
B)  rRNA 
C)  tRNA 
D)  All of these

Exam 11: Transcription of the Genetic Code: Biosynthesis of RNA

Control of transcription in prokaryotes does not involve

Which of following statements concerning RNA transcription is false?

What is the need for a primer in transcription?

Where is the TATA box located?

Which category of ribozymes requires an external guanosine frothier action?

How do enhancers differ from promoters?

Alternative removal of exons from mRNA is important in which of the following?

Which of the following statements about eukaryotic and prokaryotic RNA polymerases, is false?

Post-transcription processing of mRNA in prokaryotes is required.

The enzyme principally responsible for RNA synthesis in Escherichia coli

Which of the following is the best description of an operon?

All of the following apply to attenuation mechanisms, except:

A single operon

The elongation and termination phases of eukaryotic transcription

Consensus sequences are

The catabolite activator protein can overcome the effect of a repressor binding to the operon.

What provides the energy for the conversion from the open complex to chain elongation?

Which is not associated with bacterial promoters?

The leucine zipper is different from other DNA binding domains, since it requires the DNA-binding protein to form a dimer.

Which of the following RNAs is noted for having a "cloverleaf" structure?

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

Biosynthesis of Nucleic Acids: Replication

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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