Question 1

If DNA were inflexible,which of the following would not function?

Accepted Answer

A) promoters 
B) promoter-proximal elements 
C) enhancers 
D) basal transcription factors 
E) the TATA-binding protein 
A) promoters 
B) promoter-proximal elements 
C) enhancers 
D) basal transcription factors 
E) the TATA-binding protein

Question 2

In the roundworm C.elegans,the lin-4 gene produces an RNA that forms a hairpin structure.One of the strands in the double-stranded region of lin-4 hairpin RNA is complementary to the mRNA of a protein-coding gene,lin-14.Predict the effect of expressing lin-4 RNA during development.

Accepted Answer

A) The lin-14 expression will fall when lin-4 expression begins. 
B) The lin-14 expression will rise when lin-4 expression begins. 
C) The lin-4 RNA will bind the promoter of the lin-14 gene,destroying the lin-14 gene. 
D) The lin-4 RNA will bind to the enhancer of lin-14,increasing lin-14 transcription. 
A) The lin-14 expression will fall when lin-4 expression begins. 
B) The lin-14 expression will rise when lin-4 expression begins. 
C) The lin-4 RNA will bind the promoter of the lin-14 gene,destroying the lin-14 gene. 
D) The lin-4 RNA will bind to the enhancer of lin-14,increasing lin-14 transcription.

Question 3

Imagine you've isolated a yeast mutant that contains a constitutively (constantly)active histone deacetylase.What phenotype do you predict for this mutant?

Accepted Answer

A) The mutant will grow rapidly. 
B) The mutant will require galactose for growth. 
C) The mutant will show low levels of gene expression. 
D) The mutant will show high levels of gene expression. 
A) The mutant will grow rapidly. 
B) The mutant will require galactose for growth. 
C) The mutant will show low levels of gene expression. 
D) The mutant will show high levels of gene expression.

Question 4

Figure 18.1  
-In the experiment shown in the figure above,Tonegawa and his colleagues were able to express β-globin in an antibody-producing cell that normally does not express β-globin.They achieved this result by splicing an enhancer from an antibody-producing gene into the protein-coding portion of the β-globin gene.They then introduced this recombinant gene into cultured antibody-producing cells.Why was the choice of antibody-producing cells-rather than,say,muscle or skin cells-critical for the success of this experiment?

Accepted Answer

A) Only the antibody-producing cells have the correct regulatory transcription factors to bind to the enhancer. 
B) Only the antibody-producing cells have the correct set of enhancers. 
C) Only the antibody-producing cells have the correct set of promoter-proximal elements. 
D) Only the antibody-producing cells have the correct set of enhancers,promoter-proximal elements,and promoters. 
E) Only the antibody-producing cells are capable of expressing recombinant genes. 
A) Only the antibody-producing cells have the correct regulatory transcription factors to bind to the enhancer. 
B) Only the antibody-producing cells have the correct set of enhancers. 
C) Only the antibody-producing cells have the correct set of promoter-proximal elements. 
D) Only the antibody-producing cells have the correct set of enhancers,promoter-proximal elements,and promoters. 
E) Only the antibody-producing cells are capable of expressing recombinant genes.

Question 5

Not long ago,it was believed that a count of the number of protein-coding genes would provide a count of the number of proteins produced in any given eukaryotic species.This is incorrect,largely due to the discovery of widespread

Accepted Answer

A) chromatin condensation control. 
B) transcriptional control. 
C) alternative splicing. 
D) translational control. 
A) chromatin condensation control. 
B) transcriptional control. 
C) alternative splicing. 
D) translational control.

Question 6

One way to detect alternative splicing of transcripts from a given gene is to

Accepted Answer

A) compare the DNA sequence of this gene to that of a gene known to be constitutively spliced. 
B) measure the relative rates of transcription of this gene compared to that of a gene known to be constitutively spliced. 
C) compare the sequences of different primary transcripts made from this gene. 
D) compare the sequences of different mRNAs made from this gene. 
A) compare the DNA sequence of this gene to that of a gene known to be constitutively spliced. 
B) measure the relative rates of transcription of this gene compared to that of a gene known to be constitutively spliced. 
C) compare the sequences of different primary transcripts made from this gene. 
D) compare the sequences of different mRNAs made from this gene.

Question 7

If the DNA sequences of a particular gene in a skin cell and a liver cell were compared,there would be

Accepted Answer

A) no differences. 
B) a small number of differences. 
C) a very large number of differences. 
D) so many differences that it would be impossible to identify corresponding genes in skin and liver cells. 
A) no differences. 
B) a small number of differences. 
C) a very large number of differences. 
D) so many differences that it would be impossible to identify corresponding genes in skin and liver cells.

Question 8

Which of the following allows more than one type of protein to be produced from one gene?

Accepted Answer

A) alternative forms of chromatin remodeling 
B) alternative forms of RNA splicing 
C) control of mRNA stability 
D) control of the frequency of translation initiation 
E) all of the above 
A) alternative forms of chromatin remodeling 
B) alternative forms of RNA splicing 
C) control of mRNA stability 
D) control of the frequency of translation initiation 
E) all of the above

Question 9

If cells of an individual contain the same set of genes,how do these cells become different from each other during development?

Accepted Answer

A) Different cell type-specific regulatory elements in DNA are created during development. 
B) Different cell type-specific regulatory elements in DNA are selectively lost during development. 
C) Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell. 
D) Differences develop in promoter sequences that lead to different signals being produced by each type of cell. 
A) Different cell type-specific regulatory elements in DNA are created during development. 
B) Different cell type-specific regulatory elements in DNA are selectively lost during development. 
C) Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell. 
D) Differences develop in promoter sequences that lead to different signals being produced by each type of cell.

Question 10

Which of the following types of mutation would convert a proto-oncogene into an oncogene?

Accepted Answer

A) a mutation that blocks transcription of the proto-oncogene 
B) a mutation that creates an unstable proto-oncogene mRNA 
C) a mutation that greatly increases the amount of the proto-oncogene protein 
D) a deletion of most of the proto-oncogene coding sequence 
A) a mutation that blocks transcription of the proto-oncogene 
B) a mutation that creates an unstable proto-oncogene mRNA 
C) a mutation that greatly increases the amount of the proto-oncogene protein 
D) a deletion of most of the proto-oncogene coding sequence

Question 11

Imagine you've isolated a yeast mutant that contains histones resistant to acetylation.What phenotype do you predict for this mutant?

Accepted Answer

A) The mutant will grow rapidly. 
B) The mutant will require galactose for growth. 
C) The mutant will show low levels of gene expression. 
D) The mutant will show high levels of gene expression. 
A) The mutant will grow rapidly. 
B) The mutant will require galactose for growth. 
C) The mutant will show low levels of gene expression. 
D) The mutant will show high levels of gene expression.

Question 12

A patient is undergoing genetic screening for cancer.The results show the patient has many proto-oncogenes.Based on this information only,which of the following statements is correct regarding the probability that this patient will develop cancer in the very near future?

Accepted Answer

A) Due to the increased number of proto-oncogenes,the chances are high. 
B) The chances are low because the patient would have to show an increased number of oncogenes. 
C) The chances are high because the patient most likely also shows an increase in the number of tumor suppressors. 
A) Due to the increased number of proto-oncogenes,the chances are high. 
B) The chances are low because the patient would have to show an increased number of oncogenes. 
C) The chances are high because the patient most likely also shows an increase in the number of tumor suppressors.

Question 13

Which of the following is FALSE?

Accepted Answer

A) All individuals possess many proto-oncogenes. 
B) Mutations that inactivate tumor suppressor genes are important in cancer. 
C) Cancer is a single disease with one underlying molecular cause. 
D) Uncontrolled cell growth alone is insufficient for the development of most cancers. 
E) Most agents that cause cancer also cause mutations. 
A) All individuals possess many proto-oncogenes. 
B) Mutations that inactivate tumor suppressor genes are important in cancer. 
C) Cancer is a single disease with one underlying molecular cause. 
D) Uncontrolled cell growth alone is insufficient for the development of most cancers. 
E) Most agents that cause cancer also cause mutations.

Question 14

A scientist has a vial containing DNA and tries to digest it with DNA digesting enzymes.After analyzing it,she finds that no digestion occurred.What would be the most likely reason for this?

Accepted Answer

A) The DNA was tightly packed into 30nm chromatin fibres. 
B) The DNA was packed into regions called euchromatin. 
C) The DNA was tightly packed into 10nm chromatin fibres. 
D) The DNA was embedded in the plasma membrane and was not accessible for the enzyme. 
A) The DNA was tightly packed into 30nm chromatin fibres. 
B) The DNA was packed into regions called euchromatin. 
C) The DNA was tightly packed into 10nm chromatin fibres. 
D) The DNA was embedded in the plasma membrane and was not accessible for the enzyme.

Question 15

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different

Accepted Answer

A) genes. 
B) regulatory sequences. 
C) sets of regulatory proteins. 
D) promoters. 
E) promoter-proximal elements. 
A) genes. 
B) regulatory sequences. 
C) sets of regulatory proteins. 
D) promoters. 
E) promoter-proximal elements.

Question 16

The rate of translation can be slowed drastically when a ribosomal protein is phosphorylated in response to a sudden temperature increase or viral infection.In this case,the phosphorylated ribosomal protein is under ________ control,and the phosphorylation of this ribosomal protein leads to widespread ________ control.

Accepted Answer

A) transcriptional;translational 
B) translational;post-translational 
C) post-translational;transcriptional 
D) post-translational;translational 
E) transcriptional;post-translational 
A) transcriptional;translational 
B) translational;post-translational 
C) post-translational;transcriptional 
D) post-translational;translational 
E) transcriptional;post-translational

Question 17

How do chromatin-remodeling complexes recognize the genes they should act on?

Accepted Answer

A) Chromatin-remodeling complexes are activated by specific extracellular signals that direct them to particular genes. 
B) Chromatin-remodeling complexes recognize specific promoters when they are phosphorylated,methylated,or acetylated. 
C) Chromatin-remodeling complexes recognize specific transcription factors bound to regulatory sequences of DNA. 
D) Chromatin-remodeling complexes bind to the basal transcription complex. 
A) Chromatin-remodeling complexes are activated by specific extracellular signals that direct them to particular genes. 
B) Chromatin-remodeling complexes recognize specific promoters when they are phosphorylated,methylated,or acetylated. 
C) Chromatin-remodeling complexes recognize specific transcription factors bound to regulatory sequences of DNA. 
D) Chromatin-remodeling complexes bind to the basal transcription complex.

Question 18

Imagine that you are studying the control of β-globin gene expression in immature red blood cells (mature red blood cells contain β-globin protein,but lack a nucleus and,therefore,the β-globin gene).If you deleted a sequence of DNA outside the protein-coding region of the β-globin gene and found that this increased the rate of transcription,the deleted sequence likely functions as a(n)

Accepted Answer

A) promoter. 
B) promoter-proximal element. 
C) enhancer. 
D) silencer. 
E) any of the above. 
A) promoter. 
B) promoter-proximal element. 
C) enhancer. 
D) silencer. 
E) any of the above.

Question 19

Twenty-five years ago,when Oshima and colleagues discovered that a mutation in the GAL4 gene led to the inability to synthesize all five enzymes required for galactose catabolism (breakdown),they couldn't be blamed for wanting to apply a bacterial model to explain this finding.What they expected,but did not find,was

Accepted Answer

A) for all five genes to constitute an operon. 
B) five widely separated genes,each containing a GAL4 binding site in its regulatory region. 
C) for chromatin decondensation to play an important role in regulating the genes of galactose catabolism. 
D) for transcription to be important in regulating the genes of galactose catabolism. 
A) for all five genes to constitute an operon. 
B) five widely separated genes,each containing a GAL4 binding site in its regulatory region. 
C) for chromatin decondensation to play an important role in regulating the genes of galactose catabolism. 
D) for transcription to be important in regulating the genes of galactose catabolism.

Exam 18: Control of Gene Expression in Eukaryotes

If DNA were inflexible,which of the following would not function?

In the roundworm C.elegans,the lin-4 gene produces an RNA that forms a hairpin structure.One of the strands in the double-stranded region of lin-4 hairpin RNA is complementary to the mRNA of a protein-coding gene,lin-14.Predict the effect of expressing lin-4 RNA during development.

Imagine you've isolated a yeast mutant that contains a constitutively (constantly)active histone deacetylase.What phenotype do you predict for this mutant?

Not long ago,it was believed that a count of the number of protein-coding genes would provide a count of the number of proteins produced in any given eukaryotic species.This is incorrect,largely due to the discovery of widespread

One way to detect alternative splicing of transcripts from a given gene is to

If the DNA sequences of a particular gene in a skin cell and a liver cell were compared,there would be

Which of the following allows more than one type of protein to be produced from one gene?

If cells of an individual contain the same set of genes,how do these cells become different from each other during development?

Which of the following types of mutation would convert a proto-oncogene into an oncogene?

Imagine you've isolated a yeast mutant that contains histones resistant to acetylation.What phenotype do you predict for this mutant?

A patient is undergoing genetic screening for cancer.The results show the patient has many proto-oncogenes.Based on this information only,which of the following statements is correct regarding the probability that this patient will develop cancer in the very near future?

Which of the following is FALSE?

A scientist has a vial containing DNA and tries to digest it with DNA digesting enzymes.After analyzing it,she finds that no digestion occurred.What would be the most likely reason for this?

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different

How do chromatin-remodeling complexes recognize the genes they should act on?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, RNA Processing, and Translation

Control of Gene Expression in Bacteria

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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