Question 1

Refer to the figure showing the pathways of microRNAs and siRNAs.   What is structure A and what is its role?

Accepted Answer

Structure A is the e

Question 2

A bacterial gene (gene A) ordinarily makes a protein that binds to DNA.A mutation of gene A decreases the expression of another gene, gene B.We can conclude that

Accepted Answer

A)  gene A is a positive regulator of gene B. 
B)  gene A is a negative regulator of gene B. 
C)  gene B is a positive regulator of gene A. 
D)  gene B is a negative regulator of gene A. 
E)  genes A and B regulate one another. 
A)  gene A is a positive regulator of gene B. 
B)  gene A is a negative regulator of gene B. 
C)  gene B is a positive regulator of gene A. 
D)  gene B is a negative regulator of gene A. 
E)  genes A and B regulate one another.

Question 3

It has been established that the absolute number of unique protein coding sequences does not correlate with organismal complexity.Which characteristic would not be consistent with this observation?

Accepted Answer

A)  There are proportionally more transcription factors in humans than in nematodes. 
B)  The noncoding portion of the human genome is proportionally larger than in nematodes. 
C)  There are more alternative splicing variants in the human brain than in a chimpanzee brain. 
D)  More miRNA sequences have been identified in humans than in fruit flies. 
E)  There are fewer siRNA regulatory sequences in petunias than in mosses. 
A)  There are proportionally more transcription factors in humans than in nematodes. 
B)  The noncoding portion of the human genome is proportionally larger than in nematodes. 
C)  There are more alternative splicing variants in the human brain than in a chimpanzee brain. 
D)  More miRNA sequences have been identified in humans than in fruit flies. 
E)  There are fewer siRNA regulatory sequences in petunias than in mosses.

Question 4

Which molecule metabolizes lactose into simple sugars?

Accepted Answer

A)  β-galactoside transacetylase 
B)  β-galactoside permease 
C)  β-galactosidase 
D)  The operator of the lac operon 
E)  The promoter of the lac operon 
A)  β-galactoside transacetylase 
B)  β-galactoside permease 
C)  β-galactosidase 
D)  The operator of the lac operon 
E)  The promoter of the lac operon

Question 5

Regulation of gene expression during the bacteriophage lytic cycle does not include

Accepted Answer

A)  binding of a host RNA polymerase to a viral promoter. 
B)  stimulation of viral late gene transcription. 
C)  enhancement of the host's gene transcription. 
D)  enhancement of viral early gene transcription. 
E)  downregulation of the host's gene transcription. 
A)  binding of a host RNA polymerase to a viral promoter. 
B)  stimulation of viral late gene transcription. 
C)  enhancement of the host's gene transcription. 
D)  enhancement of viral early gene transcription. 
E)  downregulation of the host's gene transcription.

Question 6

Which statement would best describe the genomic structure of a constitutively expressed gene?

Accepted Answer

A)  The gene is located on an X chromosome that is condensed into a Barr body. 
B)  The gene is located within a region of highly deacetylated histones. 
C)  The gene is located within a region of highly acetylated histones. 
D)  The gene is located within a region of heavy DNA CpG methylation. 
E)  The gene is located within a region of heavy histone methylation. 
A)  The gene is located on an X chromosome that is condensed into a Barr body. 
B)  The gene is located within a region of highly deacetylated histones. 
C)  The gene is located within a region of highly acetylated histones. 
D)  The gene is located within a region of heavy DNA CpG methylation. 
E)  The gene is located within a region of heavy histone methylation.

Question 7

A DNA sequence is several thousands of nucleotides distant from the promoter.When this sequence is bound by a protein, transcription rates increase greatly.This sequence is most likely a(n)

Accepted Answer

A)  TATA box. 
B)  enhancer. 
C)  operon. 
D)  promoter. 
E)  consensus sequence. 
A)  TATA box. 
B)  enhancer. 
C)  operon. 
D)  promoter. 
E)  consensus sequence.

Question 8

Which is an example of regulation of eukaryotic transcription?

Accepted Answer

A)  Iron binding the repressor protein for the ferritin mRNA and increasing ferritin expression 
B)  Proteasome breakdown of protein-polyubiquitin complexes 
C)  MicroRNAs binding their target mRNA and causing its degradation 
D)  Alternative splicing of an mRNA transcript 
E)  Activator proteins binding an enhancer 
A)  Iron binding the repressor protein for the ferritin mRNA and increasing ferritin expression 
B)  Proteasome breakdown of protein-polyubiquitin complexes 
C)  MicroRNAs binding their target mRNA and causing its degradation 
D)  Alternative splicing of an mRNA transcript 
E)  Activator proteins binding an enhancer

Question 9

For some genes, the DNA methylation pattern in sperm differs from that in eggs.The transcription of the gene that is methylated in eggs would be _______, whereas that of its unmethylated counterpart in sperm would be _______.

Accepted Answer

A)  high; low 
B)  immediate; delayed 
C)  delayed; immediate 
D)  first; second 
E)  low; high 
A)  high; low 
B)  immediate; delayed 
C)  delayed; immediate 
D)  first; second 
E)  low; high

Question 10

Ubiquitin is primarily involved in the _______ step of regulation.

Accepted Answer

A)  transcription initiation 
B)  transcription elongation 
C)  RNA processing 
D)  translation 
E)  protein longevity 
A)  transcription initiation 
B)  transcription elongation 
C)  RNA processing 
D)  translation 
E)  protein longevity

Question 11

MicroRNAs and small interfering RNAs differ in that

Accepted Answer

A)  only microRNAs silence genes. 
B)  only small interfering RNAs silence genes. 
C)  only microRNAs arise from the transcription of host DNA. 
D)  only microRNAs involve double-stranded DNA. 
E)  only small interfering RNAs involve Dicer. 
A)  only microRNAs silence genes. 
B)  only small interfering RNAs silence genes. 
C)  only microRNAs arise from the transcription of host DNA. 
D)  only microRNAs involve double-stranded DNA. 
E)  only small interfering RNAs involve Dicer.

Question 12

In the _______ cycle, bacteriophage will take over the host machinery to produce more phage.

Accepted Answer

The answer of In the _______ cycle, bacteriophage will take...

Question 13

A strain of HIV has a mutation that causes its tat protein to be somewhat more able to bind to RNA.The most likely result is that

Accepted Answer

A)  there will be more initiation of transcription. 
B)  there will be less initiation of transcription. 
C)  more partial transcripts will be terminated, thus fewer complete transcripts will be made. 
D)  fewer partial transcripts will be terminated, thus more complete transcripts will be made. 
E)  the stability of complete transcripts will be reduced. 
A)  there will be more initiation of transcription. 
B)  there will be less initiation of transcription. 
C)  more partial transcripts will be terminated, thus fewer complete transcripts will be made. 
D)  fewer partial transcripts will be terminated, thus more complete transcripts will be made. 
E)  the stability of complete transcripts will be reduced.

Question 14

A bacteriophage infects a bacterial cell.Half an hour later, hundreds of new viruses burst out from the bacterial cell.This is an example of the _______ life cycle.

Accepted Answer

A)  prophase 
B)  lytic 
C)  lysogenic 
D)  proviral 
E)  positive 
A)  prophase 
B)  lytic 
C)  lysogenic 
D)  proviral 
E)  positive

Question 15

Which enzyme allows methylation changes to be passed on after DNA replication?

Accepted Answer

A)  Demethylase 
B)  DNA methyltransferase 
C)  Methylheritablase 
D)  Maintenance methylase 
E)  CpG 
A)  Demethylase 
B)  DNA methyltransferase 
C)  Methylheritablase 
D)  Maintenance methylase 
E)  CpG

Question 16

Viruses are

Accepted Answer

A)  cells containing DNA and protein. 
B)  larger than most bacteria. 
C)  acellular. 
D)  able to take in nutrients and expel wastes. 
E)  mutated forms of DNA. 
A)  cells containing DNA and protein. 
B)  larger than most bacteria. 
C)  acellular. 
D)  able to take in nutrients and expel wastes. 
E)  mutated forms of DNA.

Question 17

Bacterial promoters of different housekeeping genes

Accepted Answer

A)  are nearly identical throughout their sequence. 
B)  can vary in sequence but share consensus sequences at which they are very similar. 
C)  can vary in sequence but share sigma factors at which they are very similar. 
D)  can vary in sequence but share regulatory sequences at which they are very similar. 
E)  can vary in sequence and share no common motifs. 
A)  are nearly identical throughout their sequence. 
B)  can vary in sequence but share consensus sequences at which they are very similar. 
C)  can vary in sequence but share sigma factors at which they are very similar. 
D)  can vary in sequence but share regulatory sequences at which they are very similar. 
E)  can vary in sequence and share no common motifs.

Question 18

If the gene encoding the lac repressor is mutated such that the repressor can no longer bind the operator, will transcription of that operon occur?

Accepted Answer

A)  Yes, because the repressor transcriptionally activates the lac genes. 
B)  Yes, but only when lactose is present. 
C)  No, because RNA polymerase is needed to transcribe the genes. 
D)  Yes, because RNA polymerase will be able to bind the promoter and transcribe the operon. 
E)  No, because cAMP levels are low when the repressor is nonfunctional. 
A)  Yes, because the repressor transcriptionally activates the lac genes. 
B)  Yes, but only when lactose is present. 
C)  No, because RNA polymerase is needed to transcribe the genes. 
D)  Yes, because RNA polymerase will be able to bind the promoter and transcribe the operon. 
E)  No, because cAMP levels are low when the repressor is nonfunctional.

Question 19

In a repressible operon, the repressor molecule

Accepted Answer

A)  is the substrate of the metabolic pathway. 
B)  can repress the transcription of the operon on its own. 
C)  is a molecule made from the operon. 
D)  binds to the mRNA. 
E)  must be activated by a co-repressor. 
A)  is the substrate of the metabolic pathway. 
B)  can repress the transcription of the operon on its own. 
C)  is a molecule made from the operon. 
D)  binds to the mRNA. 
E)  must be activated by a co-repressor.

Question 20

Coordinated expression of genes involved in drought response can occur because each of these genes possesses a _______ near its promoter.

Accepted Answer

stress res

Exam 16: Regulation of Gene Expression

Refer to the figure showing the pathways of microRNAs and siRNAs. What is structure A and what is its role?

A bacterial gene (gene A) ordinarily makes a protein that binds to DNA.A mutation of gene A decreases the expression of another gene, gene B.We can conclude that

It has been established that the absolute number of unique protein coding sequences does not correlate with organismal complexity.Which characteristic would not be consistent with this observation?

Which molecule metabolizes lactose into simple sugars?

Regulation of gene expression during the bacteriophage lytic cycle does not include

Which statement would best describe the genomic structure of a constitutively expressed gene?

A DNA sequence is several thousands of nucleotides distant from the promoter.When this sequence is bound by a protein, transcription rates increase greatly.This sequence is most likely a(n)

Which is an example of regulation of eukaryotic transcription?

For some genes, the DNA methylation pattern in sperm differs from that in eggs.The transcription of the gene that is methylated in eggs would be _______, whereas that of its unmethylated counterpart in sperm would be _______.

Ubiquitin is primarily involved in the _______ step of regulation.

MicroRNAs and small interfering RNAs differ in that

In the _______ cycle, bacteriophage will take over the host machinery to produce more phage.

A strain of HIV has a mutation that causes its tat protein to be somewhat more able to bind to RNA.The most likely result is that

A bacteriophage infects a bacterial cell.Half an hour later, hundreds of new viruses burst out from the bacterial cell.This is an example of the _______ life cycle.

Which enzyme allows methylation changes to be passed on after DNA replication?

Viruses are

Bacterial promoters of different housekeeping genes

If the gene encoding the lac repressor is mutated such that the repressor can no longer bind the operator, will transcription of that operon occur?

In a repressible operon, the repressor molecule

Coordinated expression of genes involved in drought response can occur because each of these genes possesses a _______ near its promoter.

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

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For some genes, the DNA methylation pattern in sperm differs from that in eggs.The transcription of the gene that is methylated in eggs would be _, whereas that of its unmethylated counterpart in sperm would be _.