Question 1

Post-transcriptional modification of mRNA in eukaryotes occurs after they are transported to the cytosol, but before they bind to the ribosome.

Accepted Answer

A) True 
 B)False

Question 2

Which is not part of the lac operon?

Accepted Answer

A)   lacA
B)   lacI
C)   lacY
D)   lacZ
E)   None of the above; they are all part of the lac operon

Question 3

A gene contains two 100 bp introns and three 50 bp exons. About how long is the mature RNA transcribed from this gene?

Accepted Answer

A)   75 bp
B)   150 bp
C)   200 bp
D)   350 bp
E)   Cannot tell from the information given

Question 4

Transcription termination

Accepted Answer

A)   occurs at certain DNA sequences where the elongation complex is unstable.
B)   sometimes requires a specific protein, rho, which facilitates disassembly.
C)   often occurs near pause sites.
D)   All of the above

Question 5

Which statement is false about the utilization of lactose as a carbon source by E. coli?

Accepted Answer

A)   In the presence of both glucose and lactose, the enzymes necessary for lactose catabolism are produced only in limited amounts.
B)   Lactose is the inducer for the enzymes responsible for its own catabolism.
C)   In the absence of lactose, the repressor binds to a single site upstream of the lac genes.
D)   The catabolic enzymes are encoded in a three-gene operon controlled by a single promoter.

Question 6

Which statement is not true about the binding of TBP TATA binding protein) ?

Accepted Answer

A)   The TBP subunit is only required for the initiation of transcription of class II genes.
B)   The binding of TBP to DNA distorts the DNA out of the standard B-DNA form.
C)   Contacts between TBP and DNA are mainly in the minor groove.
D)   TBP forms a saddle-shaped molecular clamp that surrounds DNA at the TATA box.

Question 7

A consensus sequence

Accepted Answer

A)   is a hypothetical sequence.
B)   indicates the nucleotides most commonly found at each position.
C)   describes the most efficient promoter sequence for the RNA polymerase holoenzyme.
D)   All of the above

Question 8

Which of the following is/are true concerning TAFs and TBP?

Accepted Answer

A)   They are subunits of TFIIB and TFIID, respectively.
B)   TBP is required to initiate transcription of class I and class III genes .
C)   They are not associated with RNA polymerase I and RNA polymerase III.
D)   All of the above

Question 9

Operons are a common gene arrangement found in all living organisms.

Accepted Answer

A) True 
 B)False

Question 10

Which is not a feature of eukaryotic mRNA processing?

Accepted Answer

A)   addition of a 5ʹ-5ʹ triphosphate linkage to GTP
B)   methylation of the terminal CCA triad
C)   addition of a polyA tail to the 3ʹ end
D)   removal of intron sequences

Question 11

Which is not generally associated with RNA processing?

Accepted Answer

A)   addition of nucleotides
B)   removal of nucleotides
C)   covalent modification of bases
D)   phosphorylation at the 3ʹ end

Question 12

Francois Jacob and Jacques Monod are responsible for

Accepted Answer

A)   discovering that the sequence of an mRNA molecule is complementary to a segment of one of the DNA strands.
B)   predicting the ʺcentral dogmaʺ of molecular biology.
C)   proposing that a single unit of heredity directed the production of a single enzyme.
D)   All of the above

Question 13

The same RNA polymerase that transcribes the ribosomal RNA transcribes all mitochondrial genes.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following is true about transcription?

Accepted Answer

A)   Promoters are regions of DNA which serve as transcription initiation sites.
B)   Initiation is the rate-limiting step in transcription.
C)   Each gene, in eukaryotic cells, usually has its own promoter.
D)   All of the above

Question 15

For an RNA hairpin loop to form, the transcribed region of the DNA sequence must .

Accepted Answer

A)   be a palindrome
B)   have dyad symmetry
C)   contain an intron
D)   have a tandem repeat

Question 16

Rho-dependent termination occurs at pause sites within the coding region.

Accepted Answer

A) True 
 B)False

Question 17

The sigma-70 subunit

Accepted Answer

A)   increases the affinity of the core polymerase for nonpromoter sequences.
B)   decreases the affinity of the core polymerase for specific promoter sequences.
C)   is responsible for transcribing many genes.
D)   is associated with a holoenzyme, enabling the formation of more stable complexes.
E)   All of the above.

Question 18

The σ70 subunit in E. coli RNA polymerase acts as a/an .

Accepted Answer

A)   repressor
B)   sliding clamp
C)   helicase
D)   initiation factor

Question 19

The CRP-cAMP complex is an activator of the lac operon.

Accepted Answer

A) True 
 B)False

Question 20

TFIIB can bind to DNA in the absence of TFIID.

Accepted Answer

A) True 
 B)False

Exam 21: Transcription and Rna Processing

Operons are a common gene arrangement found in all living organisms.

Correct AnswerverifiedShow Answer

A gene contains two 100 bp introns and three 50 bp exons. About how long is the mature RNA transcribed from this gene?

Correct AnswerverifiedShow Answer

The sigma-70 subunit

Correct AnswerverifiedShow Answer

Post-transcriptional modification of mRNA in eukaryotes occurs after they are transported to the cytosol, but before they bind to the ribosome.

Correct AnswerverifiedShow Answer

The CRP-cAMP complex is an activator of the lac operon.

Correct AnswerverifiedShow Answer

The σ70 subunit in E. coli RNA polymerase acts as a/an .

Correct AnswerverifiedShow Answer

Which is not a feature of eukaryotic mRNA processing?

Correct AnswerverifiedShow Answer

A consensus sequence

Correct AnswerverifiedShow Answer

For an RNA hairpin loop to form, the transcribed region of the DNA sequence must .

Correct AnswerverifiedShow Answer

Which of the following is true about transcription?

Correct AnswerverifiedShow Answer

Rho-dependent termination occurs at pause sites within the coding region.

Correct AnswerverifiedShow Answer

Transcription termination

Correct AnswerverifiedShow Answer

Which statement is not true about the binding of TBP TATA binding protein) ?

Correct AnswerverifiedShow Answer

TFIIB can bind to DNA in the absence of TFIID.

Correct AnswerverifiedShow Answer

The same RNA polymerase that transcribes the ribosomal RNA transcribes all mitochondrial genes.

Correct AnswerverifiedShow Answer

Francois Jacob and Jacques Monod are responsible for

Correct AnswerverifiedShow Answer

Which is not part of the lac operon?

Correct AnswerverifiedShow Answer

Which is not generally associated with RNA processing?

Correct AnswerverifiedShow Answer

Which statement is false about the utilization of lactose as a carbon source by E. coli?

Correct AnswerverifiedShow Answer

Which of the following is/are true concerning TAFs and TBP?

Correct AnswerverifiedShow Answer

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The σ⁷⁰subunit in E. coli RNA polymerase acts as a/an .

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