Question 1

If the lacI repressor gene was permanently silenced by a DNA mutation, what would be the impact on the expression of the lac operon? ​

Accepted Answer

A) The lac operon would only be expressed if glucose was absent. 
B) The lac operon would always be expressed. 
C) There would be no impact on lac operon expression. 
D) The lac operon would only be expressed when lactose was present. 
E) The lac operon would never be expressed. 
A) The lac operon would only be expressed if glucose was absent. 
B) The lac operon would always be expressed. 
C) There would be no impact on lac operon expression. 
D) The lac operon would only be expressed when lactose was present. 
E) The lac operon would never be expressed. B

Question 2

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 A

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

Which genes encode proteins that regulate the cell cycle in normal cells? ​

Accepted Answer

A) tumor suppressor genes 
B) proto-oncogenes 
C) oncogenes 
D) tumor suppressor genes and proto-oncogenes 
E) tumor suppressor genes, proto-oncogenes, and oncogenes 
A) tumor suppressor genes 
B) proto-oncogenes 
C) oncogenes 
D) tumor suppressor genes and proto-oncogenes 
E) tumor suppressor genes, proto-oncogenes, and oncogenes

Question 5

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 6

Match between columns
                        Premises: promoter

Accepted Answer

The Answer of  e and  h and  is...

Question 7

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

Question 8

Assume that a bacterial cell produces a Lac repressor that is able to bind to the operator sequence of the lac operon but cannot bind allolactose. Explain the effect on transcription of the lac operon is the presence and absence of lactose.

Accepted Answer

The Lac repressor binds the operator in

Question 9

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 10

Many breast cancers are associated with mutations in the BRCA1 gene. Explain the difference between sporadic and familial breast cancer caused by this gene at a molecular level.

Accepted Answer

In order to develop breast cancer from a

Question 11

p53 is a ____. ​

Accepted Answer

A) transcription factor that turns on expression of cell division inhibiting proteins 
B) protein encoded by an oncogene 
C) protein that promotes entry into the cell cycle when DNA is undamaged 
D) hormone used to treat cancer 
E) growth promoting factor 
A) transcription factor that turns on expression of cell division inhibiting proteins 
B) protein encoded by an oncogene 
C) protein that promotes entry into the cell cycle when DNA is undamaged 
D) hormone used to treat cancer 
E) growth promoting factor

Question 12

What is the relationship between operators, transcription units, and operons? ​

Accepted Answer

A) Operators consist of transcription units and operons. 
B) Operons consist of transcription units and operators. 
C) Operators consist of multiple transcription units associated with a single operon. 
D) Operons consist of multiple operators associated with a single transcription unit. 
E) Operons consist of multiple transcription units associated with a single operator. 
A) Operators consist of transcription units and operons. 
B) Operons consist of transcription units and operators. 
C) Operators consist of multiple transcription units associated with a single operon. 
D) Operons consist of multiple operators associated with a single transcription unit. 
E) Operons consist of multiple transcription units associated with a single operator.

Question 13

Match between columns
                        Premises: lacA

Accepted Answer

The Answer of  e and  d and  is...

Question 14

The trp operon is ____ unless tryptophan is ____. ​

Accepted Answer

A) turned on; available in the environment 
B) turned on; bound to the operator 
C) turned off; bound to the repressor 
D) turned off; bound to the promoter 
E) turned on; synthesized by the trp repressor gene 
A) turned on; available in the environment 
B) turned on; bound to the operator 
C) turned off; bound to the repressor 
D) turned off; bound to the promoter 
E) turned on; synthesized by the trp repressor gene

Question 15

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

Question 16

Posttranslational modification includes ____. ​

Accepted Answer

A) cleavage of poly-A tails from mRNA 
B) the binding of miRNAs to mRNA 
C) the chemical modification, processing, and degradation of proteins 
D) chromatin remodeling 
E) splicing of mRNAs 
A) cleavage of poly-A tails from mRNA 
B) the binding of miRNAs to mRNA 
C) the chemical modification, processing, and degradation of proteins 
D) chromatin remodeling 
E) splicing of mRNAs

Question 17

The primary difference between individual nucleated cells in a developing zygote is the ____. ​

Accepted Answer

A) genetic code of each cell 
B) differential expression of housekeeping genes 
C) differential expression of regulated genes 
D) number of chromosomes present in the nucleus 
E) presence or absence of gene regulators 
A) genetic code of each cell 
B) differential expression of housekeeping genes 
C) differential expression of regulated genes 
D) number of chromosomes present in the nucleus 
E) presence or absence of gene regulators

Question 18

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 19

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 20

The E. coli lac operon encodes three genes. These genes ____. ​

Accepted Answer

A) cleave lactose into glucose and galactose, produce transacetylase, and actively transport lactose into the cell ​ 
B) encode an enzyme that cleaves glucose, a transport protein for active transport, and a transacetylase enzyme for solubilizing lactose in the cytosol 
C) encode an enzyme that cleaves lactose, a transport protein for active transport of lactose, and a transacetylase enzyme whose function is unknown 
D) catalyze the synthesis of lactose from glucose and galactose, produce transacetylase, and actively export lactose from the cell 
E) directly interact with the Lac repressor and initiate their own transcription 
A) cleave lactose into glucose and galactose, produce transacetylase, and actively transport lactose into the cell ​ 
B) encode an enzyme that cleaves glucose, a transport protein for active transport, and a transacetylase enzyme for solubilizing lactose in the cytosol 
C) encode an enzyme that cleaves lactose, a transport protein for active transport of lactose, and a transacetylase enzyme whose function is unknown 
D) catalyze the synthesis of lactose from glucose and galactose, produce transacetylase, and actively export lactose from the cell 
E) directly interact with the Lac repressor and initiate their own transcription

Exam 16: Regulation of Gene Expression

If the lacI repressor gene was permanently silenced by a DNA mutation, what would be the impact on the expression of the lac operon? ​

Some transcriptional repressors work by ____. ​

When cells differentiate, they ____. ​

Which genes encode proteins that regulate the cell cycle in normal cells? ​

A cell that is totipotent ____. ​

Long noncoding RNAs ____. ​

Assume that a bacterial cell produces a Lac repressor that is able to bind to the operator sequence of the lac operon but cannot bind allolactose. Explain the effect on transcription of the lac operon is the presence and absence of lactose.

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

Many breast cancers are associated with mutations in the BRCA1 gene. Explain the difference between sporadic and familial breast cancer caused by this gene at a molecular level.

p53 is a ____. ​

What is the relationship between operators, transcription units, and operons? ​

The trp operon is ____ unless tryptophan is ____. ​

Many proto-oncogenes encode ____. ​

Posttranslational modification includes ____. ​

The primary difference between individual nucleated cells in a developing zygote is the ____. ​

In eukaryotic cells, ____. ​

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

The E. coli lac operon encodes three genes. These genes ____. ​

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

From DNA to Protein

Bacterial and Viral Genetics

Dna Technologies: 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

Animal Nutrition

Regulating the Internal Environment

Animal Reproduction

Animal Development

Ecology and the Biosphere

Population Ecology

Population Interactions and Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Animal Behavior

Filters

If the lacI repressor gene was permanently silenced by a DNA mutation, what would be the impact on the expression of the lac operon?

Some transcriptional repressors work by ____.

When cells differentiate, they ____.

Which genes encode proteins that regulate the cell cycle in normal cells?

A cell that is totipotent ____.

Long noncoding RNAs ____.

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

p53 is a ____.

What is the relationship between operators, transcription units, and operons?

The trp operon is unless tryptophan is .

Many proto-oncogenes encode ____.

Posttranslational modification includes ____.

The primary difference between individual nucleated cells in a developing zygote is the ____.

In eukaryotic cells, ____.

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

The E. coli lac operon encodes three genes. These genes ____.