Question 1

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

Accepted Answer

A) RNA interference. 
B) RNA obstruction. 
C) RNA blocking. 
D) RNA targeting. 
E) RNA disposal. 
A) RNA interference. 
B) RNA obstruction. 
C) RNA blocking. 
D) RNA targeting. 
E) RNA disposal.

Question 2

Use the following information to answer the questions below.
Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome.
-If she moves the promoter for the lac operon to the region between the beta galactosidase gene and the permease gene,which of the following would be likely?

Accepted Answer

A) Three structural genes will no longer be expressed. 
B) RNA polymerase will no longer transcribe permease. 
C) The operon will no longer be inducible. 
D) Beta galactosidase will be produced. 
E) The cell will continue to metabolize but more slowly. 
A) Three structural genes will no longer be expressed. 
B) RNA polymerase will no longer transcribe permease. 
C) The operon will no longer be inducible. 
D) Beta galactosidase will be produced. 
E) The cell will continue to metabolize but more slowly.

Question 3

Which of the following statements about the DNA in one of your brain cells is true?

Accepted Answer

A) Most of the DNA codes for protein. 
B) The majority of genes are likely to be transcribed. 
C) Each gene lies immediately adjacent to an enhancer. 
D) Many genes are grouped into operon-like clusters. 
E) It is the same as the DNA in one of your heart cells. 
A) Most of the DNA codes for protein. 
B) The majority of genes are likely to be transcribed. 
C) Each gene lies immediately adjacent to an enhancer. 
D) Many genes are grouped into operon-like clusters. 
E) It is the same as the DNA in one of your heart cells.

Question 4

BRCA1 and BRCA2 are considered to be tumour-suppressor genes because

Accepted Answer

A) they prevent infection by retroviruses that cause cancer. 
B) their normal products participate in repair of DNA damage. 
C) the mutant forms of either one of these promote breast cancer. 
D) the normal genes make estrogen receptors. 
E) they block penetration of breast cells by chemical carcinogens. 
A) they prevent infection by retroviruses that cause cancer. 
B) their normal products participate in repair of DNA damage. 
C) the mutant forms of either one of these promote breast cancer. 
D) the normal genes make estrogen receptors. 
E) they block penetration of breast cells by chemical carcinogens.

Question 5

If you were to observe the activity of methylated DNA,you would expect it to

Accepted Answer

A) be replicating nearly continuously. 
B) be unwinding in preparation for protein synthesis. 
C) have turned off or slowed down the process of transcription. 
D) be very actively transcribed and translated. 
E) induce protein synthesis by not allowing repressors to bind to it. 
A) be replicating nearly continuously. 
B) be unwinding in preparation for protein synthesis. 
C) have turned off or slowed down the process of transcription. 
D) be very actively transcribed and translated. 
E) induce protein synthesis by not allowing repressors to bind to it.

Question 6

Which of the following is most likely to have a small protein called ubiquitin attached to it?

Accepted Answer

A) a cyclin that usually acts in G₁, now that the cell is in G₂ 
B) a cell surface protein that requires transport from the ER 
C) an mRNA that is leaving the nucleus to be translated 
D) a regulatory protein that requires sugar residues to be attached 
E) an mRNA produced by an egg cell that will be retained until after fertilization 
A) a cyclin that usually acts in G₁, now that the cell is in G₂ 
B) a cell surface protein that requires transport from the ER 
C) an mRNA that is leaving the nucleus to be translated 
D) a regulatory protein that requires sugar residues to be attached 
E) an mRNA produced by an egg cell that will be retained until after fertilization

Question 7

Use the following information to answer the questions below.
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture.
-In one set of experiments she succeeded in decreasing methylation of histone tails.Which of the following results would she most likely see?

Accepted Answer

A) increased chromatin condensation 
B) decreased chromatin condensation 
C) abnormalities of mouse embryos 
D) decreased binding of transcription factors 
E) inactivation of the selected genes 
A) increased chromatin condensation 
B) decreased chromatin condensation 
C) abnormalities of mouse embryos 
D) decreased binding of transcription factors 
E) inactivation of the selected genes

Question 8

Steroid hormones produce their effects in cells by

Accepted Answer

A) activating key enzymes in metabolic pathways. 
B) activating translation of certain mRNAs. 
C) promoting the degradation of specific mRNAs. 
D) binding to intracellular receptors and promoting transcription of specific genes. 
E) promoting the formation of looped domains in certain regions of DNA. 
A) activating key enzymes in metabolic pathways. 
B) activating translation of certain mRNAs. 
C) promoting the degradation of specific mRNAs. 
D) binding to intracellular receptors and promoting transcription of specific genes. 
E) promoting the formation of looped domains in certain regions of DNA.

Question 9

Use the following figure to answer the questions below.
  
-What is the significance of the configuration between A and B?

Accepted Answer

A) A's configuration will not allow transcription. 
B) B's configuration allows for better packing of the chromatin. 
C) B's configuration provides a means for translation to occur. 
D) B is a polysome and will be able to make more protein faster. 
E) A is a centromere and so remains condensed. 
A) A's configuration will not allow transcription. 
B) B's configuration allows for better packing of the chromatin. 
C) B's configuration provides a means for translation to occur. 
D) B is a polysome and will be able to make more protein faster. 
E) A is a centromere and so remains condensed.

Question 10

Transcription of the genes in an inducible operon

Accepted Answer

A) occurs continuously in the cell. 
B) starts when the pathway's substrate is present. 
C) starts when the pathway's product is present. 
D) stops when the pathway's product is present. 
E) does not result in the production of enzymes. 
A) occurs continuously in the cell. 
B) starts when the pathway's substrate is present. 
C) starts when the pathway's product is present. 
D) stops when the pathway's product is present. 
E) does not result in the production of enzymes.

Question 11

Which of the following,when taken up by the cell,binds to the repressor so that the repressor no longer binds to the operator?

Accepted Answer

A) ubiquitin 
B) inducer 
C) promoter 
D) repressor 
E) corepressor 
A) ubiquitin 
B) inducer 
C) promoter 
D) repressor 
E) corepressor

Question 12

Use the following information to answer the questions below.
A geneticist introduces a transgene into yeast cells and isolates five independent cell lines in which the transgene has integrated into the yeast genome.In four of the lines,the transgene is expressed strongly,but in the fifth there is no expression at all.
-Which of the following is a likely explanation for the lack of transgene expression in the fifth cell line?

Accepted Answer

A) A transgene integrated into a heterochromatic region of the genome. 
B) A transgene integrated into a euchromatic region of the genome. 
C) The transgene was mutated during the process of integration into the host cell genome. 
D) The host cell lacks the enzymes necessary to express the transgene. 
E) A transgene integrated into a region of the genome characterized by high histone acetylation. 
A) A transgene integrated into a heterochromatic region of the genome. 
B) A transgene integrated into a euchromatic region of the genome. 
C) The transgene was mutated during the process of integration into the host cell genome. 
D) The host cell lacks the enzymes necessary to express the transgene. 
E) A transgene integrated into a region of the genome characterized by high histone acetylation.

Question 13

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon,then

Accepted Answer

A) the amino acid inactivates the repressor. 
B) the enzymes produced are called inducible enzymes. 
C) the repressor is active in the absence of the amino acid. 
D) the amino acid acts as a corepressor. 
E) the amino acid turns on transcription of the operon. 
A) the amino acid inactivates the repressor. 
B) the enzymes produced are called inducible enzymes. 
C) the repressor is active in the absence of the amino acid. 
D) the amino acid acts as a corepressor. 
E) the amino acid turns on transcription of the operon.

Question 14

Use the following information to answer the questions below.
A researcher has arrived at a method to prevent gene expression from Drosophila embryonic genes.The following questions assume that he is using this method.
-When the Bicoid protein is expressed in Drosophila,the embryo is still syncytial (divisions between cells are not yet fully developed).This information helps to explain which observation by Nüsslein-Volhard and Wieschaus?

Accepted Answer

A) mRNA from the egg is translated into the Bicoid protein. 
B) Bicoid protein diffuses throughout the embryo in a concentration gradient. 
C) Bicoid protein serves as a transcription regulator. 
D) Bicoid protein determines the dorsoventral axis of the embryo. 
E) Bicoid protein serves as a translational regulator. 
A) mRNA from the egg is translated into the Bicoid protein. 
B) Bicoid protein diffuses throughout the embryo in a concentration gradient. 
C) Bicoid protein serves as a transcription regulator. 
D) Bicoid protein determines the dorsoventral axis of the embryo. 
E) Bicoid protein serves as a translational regulator.

Question 15

If a Drosophila female has a homozygous mutation for a maternal effect gene

Accepted Answer

A) she will not develop past the early embryonic stage. 
B) all of her offspring will show the mutant phenotype, regardless of their genotype. 
C) only her male offspring will show the mutant phenotype. 
D) her offspring will show the mutant phenotype only if they are also homozygous for the mutation. 
E) only her female offspring will show the mutant phenotype. 
A) she will not develop past the early embryonic stage. 
B) all of her offspring will show the mutant phenotype, regardless of their genotype. 
C) only her male offspring will show the mutant phenotype. 
D) her offspring will show the mutant phenotype only if they are also homozygous for the mutation. 
E) only her female offspring will show the mutant phenotype.

Question 16

Use the following information to answer the questions below.
Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome.
-If she moves the repressor gene (lac I),along with its promoter,to a position at some several thousand base pairs away from its normal position,which will you expect to occur?

Accepted Answer

A) The repressor will no longer be made. 
B) The repressor will no longer bind to the operator. 
C) The repressor will no longer bind to the inducer. 
D) The lac operon will be expressed continuously. 
E) The lac operon will function normally. 
A) The repressor will no longer be made. 
B) The repressor will no longer bind to the operator. 
C) The repressor will no longer bind to the inducer. 
D) The lac operon will be expressed continuously. 
E) The lac operon will function normally.

Exam 18: Regulation of Gene Expression

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

Which of the following statements about the DNA in one of your brain cells is true?

BRCA1 and BRCA2 are considered to be tumour-suppressor genes because

If you were to observe the activity of methylated DNA,you would expect it to

Which of the following is most likely to have a small protein called ubiquitin attached to it?

Steroid hormones produce their effects in cells by

Use the following figure to answer the questions below. -What is the significance of the configuration between A and B?

Transcription of the genes in an inducible operon

Which of the following,when taken up by the cell,binds to the repressor so that the repressor no longer binds to the operator?

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon,then

If a Drosophila female has a homozygous mutation for a maternal effect gene

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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