Question 1

A repressor protein would have which of the following effects on repressible genes with a negative control mechanism?

Accepted Answer

A)  Stimulate transcription in the presence of a corepressor. 
B)  Turn off transcription in the presence of an inducer. 
C)  Stimulate transcription in the presence of a coactivator. 
D)  Turn off transcription in the presence of a corepressor. 
E)  A repressor protein does not participate in negative control mechanisms. 
A)  Stimulate transcription in the presence of a corepressor. 
B)  Turn off transcription in the presence of an inducer. 
C)  Stimulate transcription in the presence of a coactivator. 
D)  Turn off transcription in the presence of a corepressor. 
E)  A repressor protein does not participate in negative control mechanisms. D

Question 2

Temporal gene regulation refers to which of the following circumstances?

Accepted Answer

A)  Certain genes are induced only at a particular point in the organism's life cycle. 
B)  Certain genes are induced only in specific tissues. 
C)  Heat-shock genes are induced during periods of temperature stress. 
D)  "Housekeeping" genes are induced in response to a viral infection. 
E)  Molecular chaperones are synthesized after heavy-metal ingestion. 
A)  Certain genes are induced only at a particular point in the organism's life cycle. 
B)  Certain genes are induced only in specific tissues. 
C)  Heat-shock genes are induced during periods of temperature stress. 
D)  "Housekeeping" genes are induced in response to a viral infection. 
E)  Molecular chaperones are synthesized after heavy-metal ingestion. A

Question 3

Genes in euchromatic regions are:

Accepted Answer

A)  transcriptionally inactive. 
B)  duplicated 
C)  transcriptionally active. 
D)  repressed. 
E)  unregulated. 
A)  transcriptionally inactive. 
B)  duplicated 
C)  transcriptionally active. 
D)  repressed. 
E)  unregulated. C

Question 4

In female mammals, most of the inactive X chromosome becomes:

Accepted Answer

A)  associated with histones. 
B)  transcriptionally active. 
C)  euchromatin. 
D)  replicated. 
E)  heterochromatin. 
A)  associated with histones. 
B)  transcriptionally active. 
C)  euchromatin. 
D)  replicated. 
E)  heterochromatin.

Question 5

Many genes encode proteins that are always needed by a cell, and therefore are always expressed. Such genes are known as:

Accepted Answer

A)  repressible. 
B)  promoter. 
C)  constitutive. 
D)  inducible. 
E)  operons. 
A)  repressible. 
B)  promoter. 
C)  constitutive. 
D)  inducible. 
E)  operons.

Question 6

The organization of the lac operon, from upstream to downstream sequences, is represented by:

Accepted Answer

A)  repressor gene -> lacZ -> lacY -> lac A 
B)  lacZ -> lacY -> lac A 
C)  lacZ -> lacY -> lac A -> operator -> promoter 
D)  operator -> promoter -> lacZ -> lacY -> lac A 
E)  promoter -> operator -> lacZ -> lacY -> lac A 
A)  repressor gene -> lacZ -> lacY -> lac A 
B)  lacZ -> lacY -> lac A 
C)  lacZ -> lacY -> lac A -> operator -> promoter 
D)  operator -> promoter -> lacZ -> lacY -> lac A 
E)  promoter -> operator -> lacZ -> lacY -> lac A

Question 7

DNA sequences called ____ increase the rate of RNA synthesis after initiation of transcription.

Accepted Answer

A)  promoters 
B)  TATA boxes 
C)  silencers 
D)  enhancers 
E)  regulators 
A)  promoters 
B)  TATA boxes 
C)  silencers 
D)  enhancers 
E)  regulators

Question 8

Figure 14-1   The promoter in the accompanying figure is labeled as ____.

Accepted Answer

A)  6 
B)  3 
C)  1 
D)  2 
E)  7 
A)  6 
B)  3 
C)  1 
D)  2 
E)  7

Question 9

miRNA-protein complexes regulate gene expression by binding to a target mRNA and preventing translation.

Accepted Answer

A) True 
 B)False

Question 10

Acetyl groups attached to histone tails generally indicate that the genes associated with this nucleosome will be transcriptionally inactive .

Accepted Answer

A) True 
 B)False

Question 11

Sketch the main elements of an inducible operon, such as the lactose operon, and explain the functions of the operator and promoter regions.

Accepted Answer

Concepts to Consider: An operon is a set

Question 12

Considering that virtually all cells in any given individual contain the same genetic information, how is it possible to have different cell types with unique functions?

Accepted Answer

A)  Gene expression is regulated such that different cell types produce different proteins. 
B)  All cells express all proteins encoded in an organism's genes, but turn them on selectively. 
C)  Gene expression is regulated based on the age of the organism. 
D)  Only some cell types make protein products, while others do not. 
E)  Cells lose unneeded genes with each cell division. 
A)  Gene expression is regulated such that different cell types produce different proteins. 
B)  All cells express all proteins encoded in an organism's genes, but turn them on selectively. 
C)  Gene expression is regulated based on the age of the organism. 
D)  Only some cell types make protein products, while others do not. 
E)  Cells lose unneeded genes with each cell division.

Question 13

How does the lactose repressor block transcription of the lactose operon?

Accepted Answer

A)  By "turning off" the lacA intron 
B)  By degrading the lacZ protein product 
C)  By binding allosterically to the lacZ gene 
D)  By slowing the uptake of lactose into the cell 
E)  By binding to the operator 
A)  By "turning off" the lacA intron 
B)  By degrading the lacZ protein product 
C)  By binding allosterically to the lacZ gene 
D)  By slowing the uptake of lactose into the cell 
E)  By binding to the operator

Question 14

Some eukaryotic DNA sequences act as introns in the cells of some tissues and exons in the cells of other tissues. This is an example of ____, and allows for ____.

Accepted Answer

A)  positive control; feedback inhibition 
B)  gene amplification; the regulation of the rate of transcription 
C)  alternative splicing; the formation of different types of closely related proteins 
D)  DNA methylation; the formation of different types of closely related proteins 
E)  DNA replication; heterodimer formation 
A)  positive control; feedback inhibition 
B)  gene amplification; the regulation of the rate of transcription 
C)  alternative splicing; the formation of different types of closely related proteins 
D)  DNA methylation; the formation of different types of closely related proteins 
E)  DNA replication; heterodimer formation

Question 15

Repressible genes are usually actively transcribed when:

Accepted Answer

A)  repressor molecules bind to the promoter. 
B)  the end product of the enzymes encoded by these genes is low. 
C)  tryptophan accumulates in the cell. 
D)  quantities of precursor materials are high. 
E)  there is no other substrate that can be used by the cell. 
A)  repressor molecules bind to the promoter. 
B)  the end product of the enzymes encoded by these genes is low. 
C)  tryptophan accumulates in the cell. 
D)  quantities of precursor materials are high. 
E)  there is no other substrate that can be used by the cell.

Question 16

The function of the catabolite activator protein (CAP) is to:

Accepted Answer

A)  increase the affinity of the promoter region for RNA polymerase. 
B)  decrease RNA polymerase activity. 
C)  deactivate RNA polymerase after binding to AMP. 
D)  bind to and activate RNA polymerase directly. 
E)  block RNA polymerase from accessing the DNA template. 
A)  increase the affinity of the promoter region for RNA polymerase. 
B)  decrease RNA polymerase activity. 
C)  deactivate RNA polymerase after binding to AMP. 
D)  bind to and activate RNA polymerase directly. 
E)  block RNA polymerase from accessing the DNA template.

Question 17

An activator protein would have which of the following effects on an operon with a positive control mechanism?

Accepted Answer

A)  Stimulate transcription. 
B)  Turn off transcription. 
C)  Stimulate transcription when a coactivator is bound to the allosteric site. 
D)  Inhibit transcription when a coactivator is bound to the allosteric site. 
E)  Activator proteins only work on operons under negative control. 
A)  Stimulate transcription. 
B)  Turn off transcription. 
C)  Stimulate transcription when a coactivator is bound to the allosteric site. 
D)  Inhibit transcription when a coactivator is bound to the allosteric site. 
E)  Activator proteins only work on operons under negative control.

Question 18

Gene expression in bacteria is regulated primarily by:

Accepted Answer

A)  controlling the rate of DNA replication. 
B)  protein modifications. 
C)  protein degradation. 
D)  transcriptional control. 
E)  translational control. 
A)  controlling the rate of DNA replication. 
B)  protein modifications. 
C)  protein degradation. 
D)  transcriptional control. 
E)  translational control.

Question 19

Bacteria are able to respond quickly to their surroundings, such as in the presence of an abundant food source. This is because:

Accepted Answer

A)  genes for functionally related enzymes are regulated together in operons. 
B)  genes for functionally related enzymes are always constitutive. 
C)  genes for functionally related enzymes are always under positive control. 
D)  efficient protein degradation removes unneeded proteins quickly. 
E)  all bacterial genes are constitutive. 
A)  genes for functionally related enzymes are regulated together in operons. 
B)  genes for functionally related enzymes are always constitutive. 
C)  genes for functionally related enzymes are always under positive control. 
D)  efficient protein degradation removes unneeded proteins quickly. 
E)  all bacterial genes are constitutive.

Question 20

Eukaryotic transcription factors are best described as:

Accepted Answer

A)  regulators of transcription initiation of operons. 
B)  containing only a regulatory domain. 
C)  containing only a DNA binding domain. 
D)  containing a DNA binding domain plus one or more regulatory domains. 
E)  imprinted genes. 
A)  regulators of transcription initiation of operons. 
B)  containing only a regulatory domain. 
C)  containing only a DNA binding domain. 
D)  containing a DNA binding domain plus one or more regulatory domains. 
E)  imprinted genes.

Exam 14: Gene Regulation

A repressor protein would have which of the following effects on repressible genes with a negative control mechanism?

Temporal gene regulation refers to which of the following circumstances?

Genes in euchromatic regions are:

In female mammals, most of the inactive X chromosome becomes:

Many genes encode proteins that are always needed by a cell, and therefore are always expressed. Such genes are known as:

The organization of the lac operon, from upstream to downstream sequences, is represented by:

DNA sequences called ____ increase the rate of RNA synthesis after initiation of transcription.

Figure 14-1 The promoter in the accompanying figure is labeled as ____.

miRNA-protein complexes regulate gene expression by binding to a target mRNA and preventing translation.

Acetyl groups attached to histone tails generally indicate that the genes associated with this nucleosome will be transcriptionally inactive .

Sketch the main elements of an inducible operon, such as the lactose operon, and explain the functions of the operator and promoter regions.

Considering that virtually all cells in any given individual contain the same genetic information, how is it possible to have different cell types with unique functions?

How does the lactose repressor block transcription of the lactose operon?

Some eukaryotic DNA sequences act as introns in the cells of some tissues and exons in the cells of other tissues. This is an example of ____, and allows for ____.

Repressible genes are usually actively transcribed when:

The function of the catabolite activator protein (CAP) is to:

An activator protein would have which of the following effects on an operon with a positive control mechanism?

Gene expression in bacteria is regulated primarily by:

Bacteria are able to respond quickly to their surroundings, such as in the presence of an abundant food source. This is because:

Eukaryotic transcription factors are best described as:

A View of Life

Atoms and Molecules the Chemical Basis of Life

The Chemistry of Life Organic Compounds

Organization of the Cell

Biological Membranes

Cell Communication

Energy and Metabolism

How Cells Make Atp Energy-Releasing Pathways

Photosynthesis Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

The Basic Principles of Heredity

Dna the Carrier of Genetic Information

Gene Expression

Dna Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure Growth and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function an Introduction

Protection Support and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

Filters

Some eukaryotic DNA sequences act as introns in the cells of some tissues and exons in the cells of other tissues. This is an example of , and allows for .