Question 1

Which statement accurately describes global gene regulation in bacteria?

Accepted Answer

A) Sigma factors are not involved in gene regulation, only in attachment of the polymerase to the promoter. 
B) Alternative sigma factors that recognize different promoters are a mechanism of global gene regulation. 
C) E.coli cells devote more energy to the production of ribosomes during stress so that global gene regulation can occur. 
D) All promoters are recognized by all sigma factors. 
A) Sigma factors are not involved in gene regulation, only in attachment of the polymerase to the promoter. 
B) Alternative sigma factors that recognize different promoters are a mechanism of global gene regulation. 
C) E.coli cells devote more energy to the production of ribosomes during stress so that global gene regulation can occur. 
D) All promoters are recognized by all sigma factors. B

Question 2

The scientists who proposed the operon theory are

Accepted Answer

A) Monod and Jacob. 
B) Watson and Crick. 
C) Hardy and Weinberg. 
D) Darwin and Mendel. 
E) Hershey and Chase. 
A) Monod and Jacob. 
B) Watson and Crick. 
C) Hardy and Weinberg. 
D) Darwin and Mendel. 
E) Hershey and Chase. A

Question 3

What is an advantage of using the lac regulatory region to control the expression of exogenous proteins in bacterial cells?

Accepted Answer

A) Expression can be controlled by the addition of an inducer to the media. 
B) This regulatory region functions in both bacterial and mammalian cells. 
C) By using this regulatory region, eukaryotic genomic DNA can be expressed in bacterial cells. 
D) Host regulatory mechanisms are not effective when this regulatory region is cloned into a plasmid. 
A) Expression can be controlled by the addition of an inducer to the media. 
B) This regulatory region functions in both bacterial and mammalian cells. 
C) By using this regulatory region, eukaryotic genomic DNA can be expressed in bacterial cells. 
D) Host regulatory mechanisms are not effective when this regulatory region is cloned into a plasmid. A

Question 4

The sigma factor that mediates a global heat shock response in E.coli is

Accepted Answer

A) sigma 70. 
B) sigma 32. 
C) sigma 34. 
D) sigma 72. 
E) sigma 36. 
A) sigma 70. 
B) sigma 32. 
C) sigma 34. 
D) sigma 72. 
E) sigma 36.

Question 5

A mutation in a ribosome binding site in the lac operon would likely result in

Accepted Answer

A) reduction in the amount of LacZ, LacY, or LacA protein. 
B) reduction in the amount of LacZ, LacY, and LacA proteins. 
C) complete loss of transcription of the lac operon. 
D) a lac mRNA that is shorter than wild-type. 
A) reduction in the amount of LacZ, LacY, or LacA protein. 
B) reduction in the amount of LacZ, LacY, and LacA proteins. 
C) complete loss of transcription of the lac operon. 
D) a lac mRNA that is shorter than wild-type.

Question 6

As a general principle of gene regulation through operons, regulatory genes encode

Accepted Answer

A) trans-acting proteins that interact with cis-acting DNA elements. 
B) cis-acting proteins that interact with cis-acting DNA elements. 
C) cis-acting proteins that interact with trans-acting DNA elements. 
D) trans-acting proteins that interact with trans-acting DNA elements. 
A) trans-acting proteins that interact with cis-acting DNA elements. 
B) cis-acting proteins that interact with cis-acting DNA elements. 
C) cis-acting proteins that interact with trans-acting DNA elements. 
D) trans-acting proteins that interact with trans-acting DNA elements.

Question 7

What would be the phenotype of a null mutation in the gene encoding Lac repressor?

Accepted Answer

A) constitutive expression of the lac operon 
B) inducible expression of the lac operon 
C) permanently repressed expression of the lac operon 
D) cannot predict what would happen to expression of the lac operon 
A) constitutive expression of the lac operon 
B) inducible expression of the lac operon 
C) permanently repressed expression of the lac operon 
D) cannot predict what would happen to expression of the lac operon

Question 8

Which molecules are examples of effector molecules?

Accepted Answer

A) Allolactose and Trp 
B) Lac repressor and Trp repressor 
C) The promoter and operator 
D) lacY and lacZ 
E) Lactose and glucose 
A) Allolactose and Trp 
B) Lac repressor and Trp repressor 
C) The promoter and operator 
D) lacY and lacZ 
E) Lactose and glucose

Question 9

What is one possible advantage to targeting quorum-sensing mechanisms for antibiotic development?

Accepted Answer

A) There may be no selective advantage to individual cells that are resistant to quorum-sensing inhibitors. 
B) There is a selective advantage to those cells lacking a quorum-sensing system. 
C) Quorum-sensing mechanisms are found in all pathogenic bacteria. 
D) Quorum-sensing mechanisms are found only in human pathogens. 
A) There may be no selective advantage to individual cells that are resistant to quorum-sensing inhibitors. 
B) There is a selective advantage to those cells lacking a quorum-sensing system. 
C) Quorum-sensing mechanisms are found in all pathogenic bacteria. 
D) Quorum-sensing mechanisms are found only in human pathogens.

Question 10

How does tryptophan, the end product of the trp operon, function in the regulation of the operon?

Accepted Answer

A) Trp binds to and inhibits the repressor, thus allowing transcription of the operon. 
B) Trp binds to and activates the repressor, which then binds to DNA to allow transcription of the operon. 
C) Trp binds directly to DNA and inhibits transcription of the operon. 
D) Trp binds to and changes the conformation of the repressor, which can then bind DNA and block transcription of the operon. 
A) Trp binds to and inhibits the repressor, thus allowing transcription of the operon. 
B) Trp binds to and activates the repressor, which then binds to DNA to allow transcription of the operon. 
C) Trp binds directly to DNA and inhibits transcription of the operon. 
D) Trp binds to and changes the conformation of the repressor, which can then bind DNA and block transcription of the operon.

Question 11

What is the relationship between the promoters for antisense RNA and the promoters of their target genes?

Accepted Answer

A) The promoters are oriented so that they transcribe opposite strands of the same segment of DNA. 
B) The promoters are found in different chromosomal regions but are controlled by the same sigma factors. 
C) The sense and antisense RNAs use the same promoter, both RNAs are produced from a single transcript that is processed. 
D) The sense and antisense RNAs are transcribed using the same promoter that is bidirectional. 
A) The promoters are oriented so that they transcribe opposite strands of the same segment of DNA. 
B) The promoters are found in different chromosomal regions but are controlled by the same sigma factors. 
C) The sense and antisense RNAs use the same promoter, both RNAs are produced from a single transcript that is processed. 
D) The sense and antisense RNAs are transcribed using the same promoter that is bidirectional.

Question 12

An enzyme functions in a biosynthetic pathway in bacteria.You predict that the product of the reaction may regulate the levels of the protein by

Accepted Answer

A) binding an aptamer in the RNA leader sequence that alters the conformation to block the ribosome binding site. 
B) binding an aptamer in the RNA leader sequence that alters the conformation to expose the ribosome binding site. 
C) binding the promoter region to prevent transcription. 
D) binding an aptamer in the RNA leader sequence that causes an antiterminator to form. 
A) binding an aptamer in the RNA leader sequence that alters the conformation to block the ribosome binding site. 
B) binding an aptamer in the RNA leader sequence that alters the conformation to expose the ribosome binding site. 
C) binding the promoter region to prevent transcription. 
D) binding an aptamer in the RNA leader sequence that causes an antiterminator to form.

Question 13

A single DNA unit that enables the simultaneous regulation of more than one coding region in response to environmental changes is called a(n)

Accepted Answer

A) promoter. 
B) operator. 
C) regulator. 
D) inducer. 
E) operon. 
A) promoter. 
B) operator. 
C) regulator. 
D) inducer. 
E) operon.

Question 14

How was E.coli was used to aid in the cloning of the bioluminescence genes from Vibrio fischeri?

Accepted Answer

A) Gene fragments from V.fischeri were transformed into E.coli and bioluminescent E.coli were identified. 
B) Gene fragments from V.fischeri were cloned into plasmids, transformed into E.coli, and then retransformed back into V.fischeri. 
C) Gene fragments from E.coli were used to disrupt the bioluminescence genes of V.fischeri by homologous recombination. 
D) Transposons from E.coli were used to mutagenize the bioluminescence genes of V.fischeri. 
A) Gene fragments from V.fischeri were transformed into E.coli and bioluminescent E.coli were identified. 
B) Gene fragments from V.fischeri were cloned into plasmids, transformed into E.coli, and then retransformed back into V.fischeri. 
C) Gene fragments from E.coli were used to disrupt the bioluminescence genes of V.fischeri by homologous recombination. 
D) Transposons from E.coli were used to mutagenize the bioluminescence genes of V.fischeri.

Question 15

Which of the following is an example of a reporter gene?

Accepted Answer

A) The linkers that are attached to RNA molecules to perform RNA-Seq 
B) The lacZ coding sequence under the control of a prokaryotic promoter 
C) The DNase I enzyme used to digest DNA for a footprint assay 
D) A human protein expressed under the control of a prokaryotic promoter 
A) The linkers that are attached to RNA molecules to perform RNA-Seq 
B) The lacZ coding sequence under the control of a prokaryotic promoter 
C) The DNase I enzyme used to digest DNA for a footprint assay 
D) A human protein expressed under the control of a prokaryotic promoter

Question 16

Small RNAs can regulate gene expression by

Accepted Answer

A) binding target RNAs and inhibiting translation. 
B) binding rho and preventing termination. 
C) binding target promoter regions and preventing transcription. 
D) binding target operator regions and preventing transcription. 
A) binding target RNAs and inhibiting translation. 
B) binding rho and preventing termination. 
C) binding target promoter regions and preventing transcription. 
D) binding target operator regions and preventing transcription.

Question 17

A fragment of DNA with a radioactive label is incubated with DNase in the presence and absence of a protein that acts as a positive regulator of transcription.The samples are then run on a gel and visualized with autoradiography.Which statement describes a possible result and conclusion from such an experiment?

Accepted Answer

A) The banding pattern on the gel is the same with and without the transcriptional regulator, therefore the protein binds the DNA fragment. 
B) Some bands on the gel are absent in the sample with the transcriptional regulator, therefore the protein does not bind the DNA fragment. 
C) Some bands on the gel are absent in the sample with the transcriptional regulator, therefore the protein binds the DNA fragment. 
D) Some bands on the gel are absent in the sample without the transcriptional regulator, therefore the protein does not bind the DNA fragment. 
A) The banding pattern on the gel is the same with and without the transcriptional regulator, therefore the protein binds the DNA fragment. 
B) Some bands on the gel are absent in the sample with the transcriptional regulator, therefore the protein does not bind the DNA fragment. 
C) Some bands on the gel are absent in the sample with the transcriptional regulator, therefore the protein binds the DNA fragment. 
D) Some bands on the gel are absent in the sample without the transcriptional regulator, therefore the protein does not bind the DNA fragment.

Question 18

Alterations to DNA sites such as promoters and operators can act

Accepted Answer

A) only in cis. 
B) only in trans. 
C) either in trans or in cis. 
D) These terms apply only to posttranscriptional regulation. 
A) only in cis. 
B) only in trans. 
C) either in trans or in cis. 
D) These terms apply only to posttranscriptional regulation.

Question 19

The function of a helix-turn-helix motif in a transcription factor is to

Accepted Answer

A) recruit RNA polymerase. 
B) form dimers with other transcription factors. 
C) bind a specific sequence in the major groove of DNA. 
D) unwind the double helix. 
A) recruit RNA polymerase. 
B) form dimers with other transcription factors. 
C) bind a specific sequence in the major groove of DNA. 
D) unwind the double helix.

Question 20

In E.coli the heat shock response, which alters the proteins produced by the cell at different temperatures, is mediated by

Accepted Answer

A) degradation of chaperone proteins at high temperatures. 
B) denaturing of DNA in the promoters in the genes of heat-sensitive proteins. 
C) synthesis of alternative sigma factors at high temperatures to activate transcription of heat-shock genes. 
D) increasing the promoter affinity of already existing polymerase sigma factors at high temperatures. 
A) degradation of chaperone proteins at high temperatures. 
B) denaturing of DNA in the promoters in the genes of heat-sensitive proteins. 
C) synthesis of alternative sigma factors at high temperatures to activate transcription of heat-shock genes. 
D) increasing the promoter affinity of already existing polymerase sigma factors at high temperatures.

Exam 16: Gene Regulation in Prokaryotes

Which statement accurately describes global gene regulation in bacteria?

The scientists who proposed the operon theory are

What is an advantage of using the lac regulatory region to control the expression of exogenous proteins in bacterial cells?

The sigma factor that mediates a global heat shock response in E.coli is

A mutation in a ribosome binding site in the lac operon would likely result in

As a general principle of gene regulation through operons, regulatory genes encode

What would be the phenotype of a null mutation in the gene encoding Lac repressor?

Which molecules are examples of effector molecules?

What is one possible advantage to targeting quorum-sensing mechanisms for antibiotic development?

How does tryptophan, the end product of the trp operon, function in the regulation of the operon?

What is the relationship between the promoters for antisense RNA and the promoters of their target genes?

An enzyme functions in a biosynthetic pathway in bacteria.You predict that the product of the reaction may regulate the levels of the protein by

A single DNA unit that enables the simultaneous regulation of more than one coding region in response to environmental changes is called a(n)

How was E.coli was used to aid in the cloning of the bioluminescence genes from Vibrio fischeri?

Which of the following is an example of a reporter gene?

Small RNAs can regulate gene expression by

Alterations to DNA sites such as promoters and operators can act

The function of a helix-turn-helix motif in a transcription factor is to

In E.coli the heat shock response, which alters the proteins produced by the cell at different temperatures, is mediated by

Genetics: the Study of Biological Information

Mendels Principles of Heredity

Extensions to Mendels Laws

The Chromosome Theory of Inheritance

Linkage, Recombination, and the Mapping of Genes on Chromosomes

DNA Structure, Replication, and Recombination

Anatomy and Function of a Gene: Dissection Through Mutation

Gene Expression: the Flow of Information From Dna to Rna to Protein

Digital Analysis of Dna

Genome Annotation

Analyzing Genomic Variation

The Eukaryotic Chromosome

Chromosomal Rearrangements and Changes in Chromosome Number

Bacterial Genetics

Organellar Inheritance

Gene Regulation in Eukaryotes

Manipulating the Genomes of Eukaryotes

The Genetic Analysis of Development

The Genetics of Cancer

Variation and Selection in Populations

The Genetics of Complex Traits

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