Question 1

A repressor operon regulates the gene expression of anabolic pathways.
__________________

Accepted Answer

A) True 
 B)False  True

Question 2

The operator of the lactose operon in E.coli is located:

Accepted Answer

A)  between the promoter and the TATA box. 
B)  upstream of the promoter. 
C)  between the promoter and the structural genes. 
D)  among the structural genes. 
E)  anywhere on the chromosome. 
A)  between the promoter and the TATA box. 
B)  upstream of the promoter. 
C)  between the promoter and the structural genes. 
D)  among the structural genes. 
E)  anywhere on the chromosome. C

Question 3

Explain the respective advantages associated with operons being inducible (e.g., the lactose operon) or repressible (e.g., the tryptophan operon).

Accepted Answer

Inducible operons save energy for the prokaryotes because the proteins of the operon are only synthesized when needed for survival.
The advantage of a repressible operons is that they prevent excess production of a metabolite.

Question 4

A cell may meet the need for large quantities of a specific protein by all of the following EXCEPT :

Accepted Answer

A)  continuously synthesizing the mRNA molecule that specifies that protein. 
B)  increasing the half-life of the mRNA that specifies the protein. 
C)  having multiple copies of the gene that codes for that protein. 
D)  amplifying protein genes by DNA replication 
E)  inhibition of DNA synthesis 
A)  continuously synthesizing the mRNA molecule that specifies that protein. 
B)  increasing the half-life of the mRNA that specifies the protein. 
C)  having multiple copies of the gene that codes for that protein. 
D)  amplifying protein genes by DNA replication 
E)  inhibition of DNA synthesis

Question 5

In female mammals, most of the inactive X chromosome has become:

Accepted Answer

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

Question 6

The gene that codes for the repressor protein of the E.coli lactose operon is:

Accepted Answer

A)  located between the operator and the promoter. 
B)  downstream from the promoter region. 
C)  downstream from the operator. 
D)  constitutive. 
E)  turned off most of the time. 
A)  located between the operator and the promoter. 
B)  downstream from the promoter region. 
C)  downstream from the operator. 
D)  constitutive. 
E)  turned off most of the time.

Question 7

Temporal gene regulation refers to which of the following circumstances?

Accepted Answer

A)  Certain genes are induced only at a particular point in the 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 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.

Question 8

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

Accepted Answer

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

Question 9

An inducible operon is usually controlled by:

Accepted Answer

A)  an inducer molecule that keeps it in the "off" state. 
B)  an active repressor that keeps it in the "off" state. 
C)  being active at all times. 
D)  allolactose. 
E)  being turned "off," usually by the end product of the pathway. 
A)  an inducer molecule that keeps it in the "off" state. 
B)  an active repressor that keeps it in the "off" state. 
C)  being active at all times. 
D)  allolactose. 
E)  being turned "off," usually by the end product of the pathway.

Question 10

Regulation of gene expression can NOT be accomplished by controlling:

Accepted Answer

A)  the activity of a protein product. 
B)  the amount of mRNA that is available. 
C)  the rate of translation of mRNA. 
D)  the rate of mRNA degradation. 
E)  the rate of DNA replication 
A)  the activity of a protein product. 
B)  the amount of mRNA that is available. 
C)  the rate of translation of mRNA. 
D)  the rate of mRNA degradation. 
E)  the rate of DNA replication

Question 11

Why is it important that a few $\beta$-galactosidase molecules be present in E.coli even if these cells have been growing on a lactose-free medium?

Accepted Answer

Concepts to Consider: It is im

Question 12

A repressible operon is usually controlled by:

Accepted Answer

A)  an inactive repressor that allows it to be in the "on" state. 
B)  the supply of the precursor product for the enzymes. 
C)  an inactive repressor that keeps it in the "off" state. 
D)  tryptophan. 
E)  being turned "on," usually by the end product of the pathway. 
A)  an inactive repressor that allows it to be in the "on" state. 
B)  the supply of the precursor product for the enzymes. 
C)  an inactive repressor that keeps it in the "off" state. 
D)  tryptophan. 
E)  being turned "on," usually by the end product of the pathway.

Question 13

Some eukaryotic DNA sequences act as introns in the cells of some tissues and exons in the cells of other tissues.This allows:

Accepted Answer

A)  prevention of harmful mutation. 
B)  regulation of the rate of transcription. 
C)  formation of different types of closely related proteins. 
D)  regulation of the rate of translation. 
E)  repression of DNA replication. 
A)  prevention of harmful mutation. 
B)  regulation of the rate of transcription. 
C)  formation of different types of closely related proteins. 
D)  regulation of the rate of translation. 
E)  repression of DNA replication.

Question 14

In the tryptophan operon, the repressor actively binds to the operator when:

Accepted Answer

A)  tryptophan binds to an allosteric site on the repressor. 
B)  tryptophan levels are low. 
C)  lactose levels are low. 
D)  there is a great need for proteins. 
E)  allotryptophan levels are low. 
A)  tryptophan binds to an allosteric site on the repressor. 
B)  tryptophan levels are low. 
C)  lactose levels are low. 
D)  there is a great need for proteins. 
E)  allotryptophan levels are low.

Question 15

Feedback inhibition is:

Accepted Answer

A)  transcriptional control. 
B)  transcriptional control 
C)  a mechanism affecting events after translation. 
D)  a repressible system. 
E)  constitiutive control 
A)  transcriptional control. 
B)  transcriptional control 
C)  a mechanism affecting events after translation. 
D)  a repressible system. 
E)  constitiutive control

Question 16

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

Accepted Answer

A)  by "turning off" the appropriate genes in the intron 
B)  by regulating the activity of the enzymes that the operon codes for 
C)  by binding allosterically to the appropriate genes 
D)  by slowing the uptake of lactose into the cell 
E)  by binding to the operator 
A)  by "turning off" the appropriate genes in the intron 
B)  by regulating the activity of the enzymes that the operon codes for 
C)  by binding allosterically to the appropriate genes 
D)  by slowing the uptake of lactose into the cell 
E)  by binding to the operator

Question 17

Genes in euchromatic regions are:

Accepted Answer

A)  inhibited. 
B)  duplicated 
C)  actively being transcribed. 
D)  repressed. 
E)  unregulated. 
A)  inhibited. 
B)  duplicated 
C)  actively being transcribed. 
D)  repressed. 
E)  unregulated.

Question 18

MATCHING
Match the type of gene regulation with the process.
a.regulation of transcription
d.regulation of translation
b.regulation of mRNA processing
e.regulation of chromatin
c.regulation of mRNA transport
-Controlling access to nuclear pores

Accepted Answer

The answer of MATCHING
Match the type of gene regulation with...

Question 19

MATCHING
Match the type of gene regulation with the process.
a.regulation of transcription
d.regulation of translation
b.regulation of mRNA processing
e.regulation of chromatin
c.regulation of mRNA transport
-Unpacked heterochromatin

Accepted Answer

The answer of MATCHING
Match the type of gene regulation with...

Question 20

Mutations in the TATA box increase the rate of transcription.
__________________

Accepted Answer

A) True 
 B)False

Exam 14: Gene Regulation

A repressor operon regulates the gene expression of anabolic pathways. __________________

The operator of the lactose operon in E.coli is located:

Explain the respective advantages associated with operons being inducible (e.g., the lactose operon) or repressible (e.g., the tryptophan operon).

A cell may meet the need for large quantities of a specific protein by all of the following EXCEPT :

In female mammals, most of the inactive X chromosome has become:

The gene that codes for the repressor protein of the E.coli lactose operon is:

Temporal gene regulation refers to which of the following circumstances?

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

An inducible operon is usually controlled by:

Regulation of gene expression can NOT be accomplished by controlling:

Why is it important that a few β\betaβ -galactosidase molecules be present in E.coli even if these cells have been growing on a lactose-free medium?

A repressible operon is usually controlled by:

Some eukaryotic DNA sequences act as introns in the cells of some tissues and exons in the cells of other tissues.This allows:

In the tryptophan operon, the repressor actively binds to the operator when:

Feedback inhibition is:

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

Genes in euchromatic regions are:

MATCHING Match the type of gene regulation with the process. a.regulation of transcription d.regulation of translation b.regulation of mRNA processing e.regulation of chromatin c.regulation of mRNA transport -Controlling access to nuclear pores

MATCHING Match the type of gene regulation with the process. a.regulation of transcription d.regulation of translation b.regulation of mRNA processing e.regulation of chromatin c.regulation of mRNA transport -Unpacked heterochromatin

Mutations in the TATA box increase the rate of transcription. __________________

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

Why is it important that a few $\beta$ -galactosidase molecules be present in E.coli even if these cells have been growing on a lactose-free medium?