Question 1

Compare the functions of maternal-effect genes, segmentation genes, and homeotic genes in Drosophila .

Accepted Answer

Maternal-effect genes are expressed in the mother, and the transcripts are stored in the egg in patterns that dictate the anterior-posterior polarity of the egg and, therefore, the developing embryo. Segmentation genes are responsible for progressively subdividing the embryo into particular regions. Homeotic genes are master regulatory genes that specify what each segment will become by controlling the development of structures, such as wings, antennae, legs, and eyes on particular segments.

Question 2

Long noncoding RNAs ____.

Accepted Answer

A)  are transcribed by RNA polymerase I rather than by RNA polymerase II 
B)  do not have their introns removed 
C)  are missing a 5' cap and 3' poly(
A)  tail 
D)  may regulate the expression of protein-coding genes 
E)  encode large proteins 
A)  are transcribed by RNA polymerase I rather than by RNA polymerase II 
B)  do not have their introns removed 
C)  are missing a 5' cap and 3' poly(
A)  tail 
D)  may regulate the expression of protein-coding genes 
E)  encode large proteins D

Question 3

When cells differentiate, they ____.

Accepted Answer

A)  lose DNA 
B)  remain totipotent 
C)  express a specific subset of genes 
D)  stop growing 
E)  gain DNA 
A)  lose DNA 
B)  remain totipotent 
C)  express a specific subset of genes 
D)  stop growing 
E)  gain DNA C

Question 4

A cell that is totipotent ____.

Accepted Answer

A)  has the potential to become any cell type of the adult 
B)  induces nearby cells to follow a certain developmental pathway 
C)  will never differentiate 
D)  will not undergo determination 
E)  has unregulated gene expression 
A)  has the potential to become any cell type of the adult 
B)  induces nearby cells to follow a certain developmental pathway 
C)  will never differentiate 
D)  will not undergo determination 
E)  has unregulated gene expression

Question 5

Acetylation adds a ____ group ____.

Accepted Answer

A)  CH3CO-; to the cytosine nucleotides of DNA 
B)  CH3CH2-; to the DNA of a promoter sequence 
C)  CH3CO-; to the histone protecting the transcription unit of a gene 
D)  CH3CO-; to the histone protecting the promoter region of a gene 
E)  CH3CH2-; to the RNA polymerase that will initiate transcription at the promoter region 
A)  CH3CO-; to the cytosine nucleotides of DNA 
B)  CH3CH2-; to the DNA of a promoter sequence 
C)  CH3CO-; to the histone protecting the transcription unit of a gene 
D)  CH3CO-; to the histone protecting the promoter region of a gene 
E)  CH3CH2-; to the RNA polymerase that will initiate transcription at the promoter region

Question 6

Eukaryotic cells regulate the expression of multiple genes by having ____.

Accepted Answer

A)  individual activators for individual genes 
B)  a few activators that can interact with small subsets of genes 
C)  activators that serve as catalysts for further activator protein synthesis 
D)  a few activators that work in different combinations to activate different genes 
E)  a single activator that undergoes modifications to enable interaction with different promoters 
A)  individual activators for individual genes 
B)  a few activators that can interact with small subsets of genes 
C)  activators that serve as catalysts for further activator protein synthesis 
D)  a few activators that work in different combinations to activate different genes 
E)  a single activator that undergoes modifications to enable interaction with different promoters

Question 7

Why is ubiquitin nicknamed the "doom tag"?

Accepted Answer

A)  When ubiquitin binds to a target protein, the ubiquitin enzyme degrades the protein. 
B)  When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded. 
C)  If a cell is deficient in ubiquitin, the cell will die. 
D)  High levels of ubiquitin in a cell cause the cell to destroy vital proteins, leading to premature cell death. 
E)  Ubiquitin binds to ribosomes and prevents them from translating proteins necessary for cell survival. 
A)  When ubiquitin binds to a target protein, the ubiquitin enzyme degrades the protein. 
B)  When ubiquitin binds to a target protein, the complex is sent to the proteasome and degraded. 
C)  If a cell is deficient in ubiquitin, the cell will die. 
D)  High levels of ubiquitin in a cell cause the cell to destroy vital proteins, leading to premature cell death. 
E)  Ubiquitin binds to ribosomes and prevents them from translating proteins necessary for cell survival.

Question 8

In eukaryotes, ____ regulation is the first level at which gene expression is controlled.

Accepted Answer

A)  transcriptional 
B)  translational 
C)  posttranscriptional 
D)  posttranslational 
E)  replicative 
A)  transcriptional 
B)  translational 
C)  posttranscriptional 
D)  posttranslational 
E)  replicative

Question 9

Some transcriptional repressors work by ____.

Accepted Answer

A)  binding to the same sequence where activators normally bind 
B)  binding to and disabling the activator 
C)  recruiting histone acetylation enzymes and thus interfering with chromatin remodeling 
D)  binding to RNA polymerase II and preventing it from binding to the transcription factor complex 
E)  methylating DNA 
A)  binding to the same sequence where activators normally bind 
B)  binding to and disabling the activator 
C)  recruiting histone acetylation enzymes and thus interfering with chromatin remodeling 
D)  binding to RNA polymerase II and preventing it from binding to the transcription factor complex 
E)  methylating DNA

Question 10

Hox genes, one class of ____ genes, contain a conserved ____ region and encode transcription factors.  These encoded transcription factors contain a _____ that corresponds to the conserved region in the Hox genes and binds to the regulatory sequences of the target genes whose transcription they regulate.

Accepted Answer

A)  maternal-effect; homeodomain; homeobox 
B)  segmentation; homeobox; homeodomain 
C)  segmentation; homeodomain; homeobox 
D)  homeobox; homeobox; homeodomain 
E)  homeobox; homeodomain; homeobox 
A)  maternal-effect; homeodomain; homeobox 
B)  segmentation; homeobox; homeodomain 
C)  segmentation; homeodomain; homeobox 
D)  homeobox; homeobox; homeodomain 
E)  homeobox; homeodomain; homeobox

Question 11

Genes expressed in almost all cell types are called ____ genes.

Accepted Answer

A)  housekeeping 
B)  regulated 
C)  activator 
D)  homeotic 
E)  structural 
A)  housekeeping 
B)  regulated 
C)  activator 
D)  homeotic 
E)  structural

Question 12

In eukaryotic cells, ____.

Accepted Answer

A)  gene expression is regulated mostly at the level of transcription 
B)  all mRNAs tend to remain stable for about the same length of time 
C)  mRNA activity is altered through modifications, such as phosphorylation 
D)  promoters are typically "on" in the absence of regulatory proteins 
E)  genes involved in similar processes are clustered together in operons 
A)  gene expression is regulated mostly at the level of transcription 
B)  all mRNAs tend to remain stable for about the same length of time 
C)  mRNA activity is altered through modifications, such as phosphorylation 
D)  promoters are typically "on" in the absence of regulatory proteins 
E)  genes involved in similar processes are clustered together in operons

Question 13

RNAi could be used as an anti-viral treatment by ____ and thus preventing viral infection and spread.

Accepted Answer

A)  degrading the viral genome or mRNAs and stopping key viral protein production 
B)  increasing immune system response to the virus 
C)  binding to receptors on host cells used for viral entry 
D)  promoting expression of viral DNA-degrading enzymes 
E)  stimulating host cells to produce anti-viral compounds 
A)  degrading the viral genome or mRNAs and stopping key viral protein production 
B)  increasing immune system response to the virus 
C)  binding to receptors on host cells used for viral entry 
D)  promoting expression of viral DNA-degrading enzymes 
E)  stimulating host cells to produce anti-viral compounds

Question 14

What is the relationship between operons and transcription units?

Accepted Answer

A)  They are synonymous terms. 
B)  An operon consists of a transcription unit plus associated regulatory DNA sequences. 
C)  A transcription unit consists of an operon plus associated regulatory DNA sequences. 
D)  An operon is composed of multiple transcription units. 
E)  A transcription unit is composed of multiple operons. 
A)  They are synonymous terms. 
B)  An operon consists of a transcription unit plus associated regulatory DNA sequences. 
C)  A transcription unit consists of an operon plus associated regulatory DNA sequences. 
D)  An operon is composed of multiple transcription units. 
E)  A transcription unit is composed of multiple operons.

Question 15

Steroid hormones can trigger gene expression in a select number of cells because ____.

Accepted Answer

A)  only target cells allow the steroid hormone to cross the plasma membrane 
B)  nontarget cells have a steroid hormone response element encoded in their DNA 
C)  only target cells have the correct receptor in their cytosol to bind to the hormone 
D)  nontarget cells lack the genes found in target cells 
E)  only target cells have the genes that steroid hormones activate 
A)  only target cells allow the steroid hormone to cross the plasma membrane 
B)  nontarget cells have a steroid hormone response element encoded in their DNA 
C)  only target cells have the correct receptor in their cytosol to bind to the hormone 
D)  nontarget cells lack the genes found in target cells 
E)  only target cells have the genes that steroid hormones activate

Question 16

A small molecule of RNA is transcribed in the nucleus. It is folded, cleaved by the Dicer enzyme, forms a complex with proteins, which then binds to a target molecule of mRNA. This molecule of RNA must be ____.

Accepted Answer

A)  miRNA 
B)  siRNA 
C)  an mRNA that was not properly capped 
D)  an mRNA that never received its poly-A tail 
E)  a transcript for a repressor protein 
A)  miRNA 
B)  siRNA 
C)  an mRNA that was not properly capped 
D)  an mRNA that never received its poly-A tail 
E)  a transcript for a repressor protein

Question 17

In a process called ____, cells lose their normal regulatory controls and revert partially or completely to an embryonic developmental state.

Accepted Answer

A)  metastasis 
B)  embryogenesis 
C)  induction 
D)  determination 
E)  dedifferentiation 
A)  metastasis 
B)  embryogenesis 
C)  induction 
D)  determination 
E)  dedifferentiation

Question 18

The role of a tumor suppressor protein in a cell is to ____.

Accepted Answer

A)  promote cell division of healthy cells 
B)  inhibit cell growth and division 
C)  promote cell division of abnormal cells 
D)  trigger DNA replication in preparation for cell division 
E)  serve as a cell receptor for growth factors 
A)  promote cell division of healthy cells 
B)  inhibit cell growth and division 
C)  promote cell division of abnormal cells 
D)  trigger DNA replication in preparation for cell division 
E)  serve as a cell receptor for growth factors

Question 19

Pepsin, a digestive enzyme that degrades proteins in the stomach, is synthesized as pepsinogen and converted to active pepsin in the stomach by the removal of several amino acids. The activation of pepsin is an example of ____.

Accepted Answer

A)  transcriptional regulation 
B)  translational regulation 
C)  posttranscriptional regulation 
D)  posttranslational regulation 
E)  RNAi 
A)  transcriptional regulation 
B)  translational regulation 
C)  posttranscriptional regulation 
D)  posttranslational regulation 
E)  RNAi

Question 20

Many proto-oncogenes encode ____.

Accepted Answer

A)  growth-inhibiting factors 
B)  intracellular receptors 
C)  tumor suppressor proteins 
D)  receptors for growth-inhibiting factors 
E)  growth factors 
A)  growth-inhibiting factors 
B)  intracellular receptors 
C)  tumor suppressor proteins 
D)  receptors for growth-inhibiting factors 
E)  growth factors

Exam 16: Regulation of Gene Expression

Compare the functions of maternal-effect genes, segmentation genes, and homeotic genes in Drosophila .

Long noncoding RNAs ____.

When cells differentiate, they ____.

A cell that is totipotent ____.

Acetylation adds a ____ group ____.

Eukaryotic cells regulate the expression of multiple genes by having ____.

Why is ubiquitin nicknamed the "doom tag"?

In eukaryotes, ____ regulation is the first level at which gene expression is controlled.

Some transcriptional repressors work by ____.

Genes expressed in almost all cell types are called ____ genes.

In eukaryotic cells, ____.

RNAi could be used as an anti-viral treatment by ____ and thus preventing viral infection and spread.

What is the relationship between operons and transcription units?

Steroid hormones can trigger gene expression in a select number of cells because ____.

A small molecule of RNA is transcribed in the nucleus. It is folded, cleaved by the Dicer enzyme, forms a complex with proteins, which then binds to a target molecule of mRNA. This molecule of RNA must be ____.

In a process called ____, cells lose their normal regulatory controls and revert partially or completely to an embryonic developmental state.

The role of a tumor suppressor protein in a cell is to ____.

Pepsin, a digestive enzyme that degrades proteins in the stomach, is synthesized as pepsinogen and converted to active pepsin in the stomach by the removal of several amino acids. The activation of pepsin is an example of ____.

Many proto-oncogenes encode ____.

Introduction to Biological Concepts and Research

Life, Chemistry, and Water

Biological Molecules: the Carbon Compounds of Life

Cells

Membranes and Transport

Energy, Enzymes, and Biological Reactions

Cellular Respiration: Harvesting Chemical Energy

Photosynthesis

Cell Communication

Cell Division and Mitosis

Meiosis: the Cellular Basis of Sexual Reproduction

Mendel, Genes, and Inheritance

Genes, Chromosomes, and Human Genetics

Dna Structure, Replication, and Organization

Gene Expression: From Dna to Protein

Bacterial and Viral Genetics

Dna Technology: Making and Using Genetically Altered Organisms, and Other Applications

Genomes and Proteomes

The Development of Evolutionary Thought

Microevolution: Genetic Changes Within Populations

Speciation

Paleobiology and Macroevolution

Systematic Biology: Phylogeny and Classification

The Origin of Life

Prokaryotes and Viruses

Protists

Seedless Plants

Seed Plants

Fungi

Animal Phylogeny, Acoelomates, and Protostomes

Deuterostomes: Vertebrates and Their Closest Relatives

The Plant Body

Transport in Plants

Plant Nutrition

Reproduction and Development in Flowering Plants

Plant Signals and Responses to the Environment

Introduction to Animal Organization and Physiology

Information Flow and the Neuron

Nervous Systems

Sensory Systems

The Endocrine System

Muscles, Bones, and Body Movements

The Circulatory System

Defenses Against Disease

Gas Exchange: the Respiratory System

Digestive Systems and Animal Nutrition

Regulating the Internal Environment: Osmoregulation, Excretion, and Thermoregulation

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

Acetylation adds a group .