Question 1

A small percentage of the total RNA in a cell is ribosomal RNA.

Accepted Answer

A) True 
 B)False  False

Question 2

Class I genes encode large ribosomal RNA.

Accepted Answer

A) True 
 B)False  True

Question 3

Which is not true about the lac repressor?

Accepted Answer

A)  Its gene is part of the lac operon and is transcribed along with lacZ, lacA and lacY. 
B)  When it binds to DNA, it forms a loop-type structure. 
C)  It likely blocks both RNA polymerase binding as well as transcription initiation. 
D)  It binds to DNA by interaction of an α-helix with the major groove. 
A)  Its gene is part of the lac operon and is transcribed along with lacZ, lacA and lacY. 
B)  When it binds to DNA, it forms a loop-type structure. 
C)  It likely blocks both RNA polymerase binding as well as transcription initiation. 
D)  It binds to DNA by interaction of an α-helix with the major groove. A

Question 4

Which statement about RNA polymerase is false?

Accepted Answer

A)  The large beta subunit comprises the active site of the enzyme. 
B)  The alpha subunits are the scaffold for assembly of the other subunits. 
C)  The role of the omega subunit is well characterized. 
D)  All of the above are false 
A)  The large beta subunit comprises the active site of the enzyme. 
B)  The alpha subunits are the scaffold for assembly of the other subunits. 
C)  The role of the omega subunit is well characterized. 
D)  All of the above are false

Question 5

Which of the following is true about transcription?

Accepted Answer

A)  A repressor protein activates transcription of a negatively regulated gene. 
B)  A positively regulated gene can be transcribed only in the absence of active repressor. 
C)  In the absence of an activator, a negatively regulated gene is poorly transcribed. 
D)  The initiation of transcription of regulated genes is controlled by regulatory proteins which bind to specific DNA sequences. 
E)  All of the above 
A)  A repressor protein activates transcription of a negatively regulated gene. 
B)  A positively regulated gene can be transcribed only in the absence of active repressor. 
C)  In the absence of an activator, a negatively regulated gene is poorly transcribed. 
D)  The initiation of transcription of regulated genes is controlled by regulatory proteins which bind to specific DNA sequences. 
E)  All of the above

Question 6

The unwinding of DNA at the initiation site is an example of a conformational change.

Accepted Answer

A) True 
 B)False

Question 7

The sequence CCA must occur .

Accepted Answer

A)  at the 3ʹ end of both prokaryotic and eukaryotic tRNA 
B)  immediately upstream from the TATA box 
C)  at the 5ʹ end of an intron 
D)  at the origin of replication in E. coli 
A)  at the 3ʹ end of both prokaryotic and eukaryotic tRNA 
B)  immediately upstream from the TATA box 
C)  at the 5ʹ end of an intron 
D)  at the origin of replication in E. coli

Question 8

An extremely large lactose source is encountered by an E. coli cell in the lumen of the small intestine of a human who just ate an entire carton of ice cream. Which of the following would most likely be a contributor to why the E. coli does not metabolize any of the lactose?

Accepted Answer

A)  presence of allolactose 
B)  presence of phosphorylated adenylate cyclase 
C)  absence of glucose 
D)  absence of cAMP 
A)  presence of allolactose 
B)  presence of phosphorylated adenylate cyclase 
C)  absence of glucose 
D)  absence of cAMP

Question 9

Positive regulation of a gene requires .

Accepted Answer

A)  an activator protein 
B)  positive cooperativity 
C)  an allosteric inducer 
D)  the conversion of ATP to ADP and inorganic phosphate 
A)  an activator protein 
B)  positive cooperativity 
C)  an allosteric inducer 
D)  the conversion of ATP to ADP and inorganic phosphate

Question 10

The template strand of DNA is copied by RNA polymerase from

Accepted Answer

A)  both 3ʹ → 5ʹ and 5ʹ → 3ʹ ends. 
B)  5-10 nucleotides before the +1 transition site. 
C)  3ʹ → 5ʹ end. 
D)  5ʹ → 3ʹ end. 
A)  both 3ʹ → 5ʹ and 5ʹ → 3ʹ ends. 
B)  5-10 nucleotides before the +1 transition site. 
C)  3ʹ → 5ʹ end. 
D)  5ʹ → 3ʹ end.

Question 11

Which is matched incorrectly?

Accepted Answer

A)  RPo-RNA polymerase at a transcription bubble of DNA 
B)  RPc-RNA polymerase bound to single-stranded DNA 
C)  NusA -helps convert RNA polymerase to an elongation form 
D)  s-protein factor aiding promoter binding 
A)  RPo-RNA polymerase at a transcription bubble of DNA 
B)  RPc-RNA polymerase bound to single-stranded DNA 
C)  NusA -helps convert RNA polymerase to an elongation form 
D)  s-protein factor aiding promoter binding

Question 12

An operon is .

Accepted Answer

A)  a set of genes whose transcription is controlled by a single promoter 
B)  the site of repressor binding 
C)  a protein that activates the transcription of a whole class of genes 
D)  a multisubunit complex responsible for the splicing of exons 
A)  a set of genes whose transcription is controlled by a single promoter 
B)  the site of repressor binding 
C)  a protein that activates the transcription of a whole class of genes 
D)  a multisubunit complex responsible for the splicing of exons

Question 13

Which of the following is correct?

Accepted Answer

A)  Transcription proceeds in the 5ʹ → 3ʹ direction. 
B)  The template strand is copied from the 5ʹ end to the 3ʹ end. 
C)  RNA polymerization proceeds in the 3ʹ → 5ʹ direction. 
D)  None of the above 
A)  Transcription proceeds in the 5ʹ → 3ʹ direction. 
B)  The template strand is copied from the 5ʹ end to the 3ʹ end. 
C)  RNA polymerization proceeds in the 3ʹ → 5ʹ direction. 
D)  None of the above

Question 14

The product of the lacZ gene is .

Accepted Answer

A)  lac repressor 
B)  β-galactosidase 
C)  thiogalactoside transacetylase 
D)  lactose permease 
A)  lac repressor 
B)  β-galactosidase 
C)  thiogalactoside transacetylase 
D)  lactose permease

Question 15

Which statement is not true about the TATA box?

Accepted Answer

A)  The TBP portion of the general transcription factor TFIID binds to the TATA box forming a molecular clamp. 
B)  It is located about 19-27 bp upstream from the transcription start site of class II genes. 
C)  Its sequence is highly conserved among all species. 
D)  This region of DNA is more easily unwound to an open complex than other general sections of DNA. 
A)  The TBP portion of the general transcription factor TFIID binds to the TATA box forming a molecular clamp. 
B)  It is located about 19-27 bp upstream from the transcription start site of class II genes. 
C)  Its sequence is highly conserved among all species. 
D)  This region of DNA is more easily unwound to an open complex than other general sections of DNA.

Question 16

Regulation of gene expression can only occur at the level of transcription.

Accepted Answer

A) True 
 B)False

Question 17

Which statement is false about operons that have the feature of catabolic repression?

Accepted Answer

A)  Several different multisubunit repressors can block the transcription of such an operon. 
B)  Operons with catabolic repression have characteristically weak promoters. 
C)  Their transcription is lowered in the presence of glucose. 
D)  Transcription of such an operon is increased as the concentration of cAMP increases. 
A)  Several different multisubunit repressors can block the transcription of such an operon. 
B)  Operons with catabolic repression have characteristically weak promoters. 
C)  Their transcription is lowered in the presence of glucose. 
D)  Transcription of such an operon is increased as the concentration of cAMP increases.

Question 18

The transcription of RNA accounts for most of the transcriptional activity of a cell.

Accepted Answer

A)  transfer 
B)  ribosomal 
C)  messenger 
D)  heterogeneous nuclear 
A)  transfer 
B)  ribosomal 
C)  messenger 
D)  heterogeneous nuclear

Question 19

Which statement is false concerning the general transcription factor, TFIID?

Accepted Answer

A)  It binds to the promoter. 
B)  Its TBP subunit binds to the region containing the TATA box. 
C)  It interacts with TFIIA in the presence of DNA. 
D)  It is the RNA polymerase II initiation factor. 
E)  None of the above 
A)  It binds to the promoter. 
B)  Its TBP subunit binds to the region containing the TATA box. 
C)  It interacts with TFIIA in the presence of DNA. 
D)  It is the RNA polymerase II initiation factor. 
E)  None of the above

Question 20

Which of the following are correct matches for the given genes?

Accepted Answer

A)  rpoN : nitrogen metabolism 
B)  rpoH : heat shock 
C)  Gene 55 : bacteriophage T4 
D)  All of the above 
A)  rpoN : nitrogen metabolism 
B)  rpoH : heat shock 
C)  Gene 55 : bacteriophage T4 
D)  All of the above

Exam 21: Transcription and Rna Processing

A small percentage of the total RNA in a cell is ribosomal RNA.

Class I genes encode large ribosomal RNA.

Which is not true about the lac repressor?

Which statement about RNA polymerase is false?

Which of the following is true about transcription?

The unwinding of DNA at the initiation site is an example of a conformational change.

The sequence CCA must occur .

An extremely large lactose source is encountered by an E. coli cell in the lumen of the small intestine of a human who just ate an entire carton of ice cream. Which of the following would most likely be a contributor to why the E. coli does not metabolize any of the lactose?

Positive regulation of a gene requires .

The template strand of DNA is copied by RNA polymerase from

Which is matched incorrectly?

An operon is .

Which of the following is correct?

The product of the lacZ gene is .

Which statement is not true about the TATA box?

Regulation of gene expression can only occur at the level of transcription.

Which statement is false about operons that have the feature of catabolic repression?

The transcription of RNA accounts for most of the transcriptional activity of a cell.

Which statement is false concerning the general transcription factor, TFIID?

Which of the following are correct matches for the given genes?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Protein Synthesis

Recombinant Dna Technology

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