Question 1

DNA methylation and histone acetylation are examples of ________.

Accepted Answer

A)  genetic mutation 
B)  chromosomal rearrangements 
C)  karyotypes 
D)  epigenetic phenomena 
E)  translocation 
A)  genetic mutation 
B)  chromosomal rearrangements 
C)  karyotypes 
D)  epigenetic phenomena 
E)  translocation

Question 2

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different ________.

Accepted Answer

A)  genes 
B)  regulatory sequences 
C)  sets of regulatory proteins 
D)  promoters 
E)  promoter-proximal elements 
A)  genes 
B)  regulatory sequences 
C)  sets of regulatory proteins 
D)  promoters 
E)  promoter-proximal elements

Question 3

Imagine that you've isolated a yeast mutant that contains histones resistant to acetylation. What phenotype do you predict for this mutant?

Accepted Answer

A)  The mutant will grow rapidly. 
B)  The mutant will require galactose for growth. 
C)  The mutant will show low levels of gene expression. 
D)  The mutant will show high levels of gene expression. 
A)  The mutant will grow rapidly. 
B)  The mutant will require galactose for growth. 
C)  The mutant will show low levels of gene expression. 
D)  The mutant will show high levels of gene expression.

Question 4

Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in eukaryotic cells?

Accepted Answer

A)  Environmental signals enter the cell and bind directly to promoters. 
B)  The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time. 
C)  The genes are organized into a large operon, allowing them to be coordinately controlled as a single unit. 
D)  A single repressor is able to turn off several related genes. 
A)  Environmental signals enter the cell and bind directly to promoters. 
B)  The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time. 
C)  The genes are organized into a large operon, allowing them to be coordinately controlled as a single unit. 
D)  A single repressor is able to turn off several related genes.

Question 5

Activator proteins in eukaryotes usually have a domain that binds to DNA and other activation domains that often bind to ________.

Accepted Answer

A)  DNA polymerases 
B)  ATP 
C)  protein-based hormones 
D)  other regulatory proteins 
E)  tRNA 
A)  DNA polymerases 
B)  ATP 
C)  protein-based hormones 
D)  other regulatory proteins 
E)  tRNA

Question 6

Which of the following types of mutation would convert a proto-oncogene into an oncogene?

Accepted Answer

A)  a mutation that blocks transcription of the proto-oncogene 
B)  a mutation that creates an unstable proto-oncogene mRNA 
C)  a mutation that greatly increases the amount of the proto-oncogene protein 
D)  a deletion of most of the proto-oncogene coding sequence 
A)  a mutation that blocks transcription of the proto-oncogene 
B)  a mutation that creates an unstable proto-oncogene mRNA 
C)  a mutation that greatly increases the amount of the proto-oncogene protein 
D)  a deletion of most of the proto-oncogene coding sequence

Question 7

Regulatory transcription factors ________.

Accepted Answer

A)  influence the binding of sigma factor to DNA 
B)  influence the assembly of the basal transcription complex 
C)  influence the degree of unwinding of DNA at the promoter 
D)  open the two strands of DNA so that RNA polymerase can begin transcription 
A)  influence the binding of sigma factor to DNA 
B)  influence the assembly of the basal transcription complex 
C)  influence the degree of unwinding of DNA at the promoter 
D)  open the two strands of DNA so that RNA polymerase can begin transcription

Question 8

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated?

Accepted Answer

A)  genes coding for enzymes that act in the colon 
B)  genes involved in control of the cell cycle 
C)  genes that are especially susceptible to mutation 
D)  genes of the bacteria, which are abundant in the colon 
A)  genes coding for enzymes that act in the colon 
B)  genes involved in control of the cell cycle 
C)  genes that are especially susceptible to mutation 
D)  genes of the bacteria, which are abundant in the colon

Question 9

Since Watson and Crick described DNA in 1953, which of the following might best explain why the function of small RNAs (miRNAs) is still not well understood?

Accepted Answer

A)  As RNAs have evolved since that time, they have taken on new functions. 
B)  Watson and Crick described DNA but did not predict any function for RNA. 
C)  The functions of small RNAs could not be approached until the entire human genome was sequenced. 
D)  Ethical considerations prevented scientists from exploring this material until recently. 
E)  Recent advances in technology and our understanding of how DNA is expressed have made this possible. 
A)  As RNAs have evolved since that time, they have taken on new functions. 
B)  Watson and Crick described DNA but did not predict any function for RNA. 
C)  The functions of small RNAs could not be approached until the entire human genome was sequenced. 
D)  Ethical considerations prevented scientists from exploring this material until recently. 
E)  Recent advances in technology and our understanding of how DNA is expressed have made this possible.

Question 10

Twenty-five years ago, when Oshima and colleagues discovered that a mutation in the GAL4 gene led to the inability to synthesize all five enzymes required for galactose catabolism (breakdown), they couldn't be blamed for wanting to apply a bacterial model to explain this finding. What they expected, but did not find, was ________.

Accepted Answer

A)  that all five genes constitute an operon 
B)  five widely separated genes, each containing a GAL4-binding site in its regulatory region 
C)  that chromatin decondensation played an important role in regulating the genes of galactose catabolism 
D)  that transcription is important in regulating the genes of galactose catabolism 
A)  that all five genes constitute an operon 
B)  five widely separated genes, each containing a GAL4-binding site in its regulatory region 
C)  that chromatin decondensation played an important role in regulating the genes of galactose catabolism 
D)  that transcription is important in regulating the genes of galactose catabolism

Question 11

Two potential devices that eukaryotic cells use to regulate transcription are ________.

Accepted Answer

A)  DNA methylation and histone amplification 
B)  DNA amplification and histone methylation 
C)  DNA acetylation and methylation 
D)  DNA methylation and histone modification 
E)  histone amplification and DNA acetylation 
A)  DNA methylation and histone amplification 
B)  DNA amplification and histone methylation 
C)  DNA acetylation and methylation 
D)  DNA methylation and histone modification 
E)  histone amplification and DNA acetylation

Question 12

At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following could account for much of the DNA that is NOT coding for proteins?

Accepted Answer

A)  most of the DNA serving as origins of DNA replication 
B)  DNA that consists of histone coding sequences 
C)  DNA that is translated directly without being transcribed 
D)  non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function 
E)  non-protein-coding DNA that serves as binding sites for reverse transcriptase 
A)  most of the DNA serving as origins of DNA replication 
B)  DNA that consists of histone coding sequences 
C)  DNA that is translated directly without being transcribed 
D)  non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function 
E)  non-protein-coding DNA that serves as binding sites for reverse transcriptase

Question 13

If the DNA sequence was substantially altered from one of the following, which would prevent the binding of the TATA-binding protein (TBP)?

Accepted Answer

A)  RNA polymerase 
B)  the point where transcription begins 
C)  the promoter 
D)  promoter-proximal elements 
E)  histone acetyl transferases (HATS) 
A)  RNA polymerase 
B)  the point where transcription begins 
C)  the promoter 
D)  promoter-proximal elements 
E)  histone acetyl transferases (HATS)

Question 14

Which of the following statements describes a eukaryotic chromosome?

Accepted Answer

A)  a single strand of DNA 
B)  a series of nucleosomes wrapped around two DNA molecules 
C)  a chromosome with different numbers of genes in different cell types of an organism 
D)  a single linear molecule of double-stranded DNA plus proteins 
A)  a single strand of DNA 
B)  a series of nucleosomes wrapped around two DNA molecules 
C)  a chromosome with different numbers of genes in different cell types of an organism 
D)  a single linear molecule of double-stranded DNA plus proteins

Question 15

The primary difference between enhancers and promoter-proximal elements is that enhancers ________.

Accepted Answer

A)  are transcription factors; promoter-proximal elements are DNA sequences 
B)  enhance transcription; promoter-proximal elements inhibit transcription 
C)  are part of the promoter; promoter-proximal elements are regulatory sequences distinct from the promoter 
D)  are at considerable distances from the promoter; promoter-proximal elements are close to the promoter 
E)  are DNA sequences; promoter-proximal elements are proteins 
A)  are transcription factors; promoter-proximal elements are DNA sequences 
B)  enhance transcription; promoter-proximal elements inhibit transcription 
C)  are part of the promoter; promoter-proximal elements are regulatory sequences distinct from the promoter 
D)  are at considerable distances from the promoter; promoter-proximal elements are close to the promoter 
E)  are DNA sequences; promoter-proximal elements are proteins

Question 16

Imagine that you have isolated a yeast mutant that contains a constitutively (constantly) active histone deacetylase. What phenotype do you predict for this mutant?

Accepted Answer

A)  The mutant will grow rapidly. 
B)  The mutant will require galactose for growth. 
C)  The mutant will show low levels of gene expression. 
D)  The mutant will show high levels of gene expression. 
A)  The mutant will grow rapidly. 
B)  The mutant will require galactose for growth. 
C)  The mutant will show low levels of gene expression. 
D)  The mutant will show high levels of gene expression.

Question 17

Mammals have a family between 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons. If all mammals have these genes, why do some mammals have a better sense of smell than others do?

Accepted Answer

A)  Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. 
B)  Some of the genes may have been mutated and rendered inactive in some species but not in others. 
C)  Some species, particularly humans, rely much less on odor detection for survival; thus, the genes have mutated to encode proteins that aid in other senses, such as sight. 
D)  Some species of mammals have a larger set of "basic odors" than other species. 
A)  Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. 
B)  Some of the genes may have been mutated and rendered inactive in some species but not in others. 
C)  Some species, particularly humans, rely much less on odor detection for survival; thus, the genes have mutated to encode proteins that aid in other senses, such as sight. 
D)  Some species of mammals have a larger set of "basic odors" than other species.

Question 18

Histone acetyl transferases exert their effect on gene activity by ________.

Accepted Answer

A)  neutralizing positive charges on the lysines of histones 
B)  introducing negative charges on the glutamic acids of histones 
C)  modifying the DNA sequence of the promoter 
D)  increasing the affinity of transcriptional activators for DNA 
E)  increasing the affinity of transcriptional inhibitors for DNA 
A)  neutralizing positive charges on the lysines of histones 
B)  introducing negative charges on the glutamic acids of histones 
C)  modifying the DNA sequence of the promoter 
D)  increasing the affinity of transcriptional activators for DNA 
E)  increasing the affinity of transcriptional inhibitors for DNA

Question 19

In eukaryotes, the normal or default state is that genes are turned ________.

Accepted Answer

A)  off through their association in nucleosomes 
B)  off through their association with exons 
C)  on through their association with exons 
D)  on through their association in nucleosomes 
A)  off through their association in nucleosomes 
B)  off through their association with exons 
C)  on through their association with exons 
D)  on through their association in nucleosomes

Question 20

Several of the different globin genes are expressed in humans but at different times in development. What mechanism could allow for this?

Accepted Answer

A)  exon shuffling 
B)  intron activation 
C)  pseudogene activation 
D)  differential translation of mRNAs 
E)  differential gene regulation over time 
A)  exon shuffling 
B)  intron activation 
C)  pseudogene activation 
D)  differential translation of mRNAs 
E)  differential gene regulation over time

Exam 19: Control of Gene Expression in Eukaryotes

DNA methylation and histone acetylation are examples of ________.

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different ________.

Imagine that you've isolated a yeast mutant that contains histones resistant to acetylation. What phenotype do you predict for this mutant?

Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in eukaryotic cells?

Activator proteins in eukaryotes usually have a domain that binds to DNA and other activation domains that often bind to ________.

Which of the following types of mutation would convert a proto-oncogene into an oncogene?

Regulatory transcription factors ________.

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated?

Since Watson and Crick described DNA in 1953, which of the following might best explain why the function of small RNAs (miRNAs) is still not well understood?

Two potential devices that eukaryotic cells use to regulate transcription are ________.

If the DNA sequence was substantially altered from one of the following, which would prevent the binding of the TATA-binding protein (TBP)?

Which of the following statements describes a eukaryotic chromosome?

The primary difference between enhancers and promoter-proximal elements is that enhancers ________.

Imagine that you have isolated a yeast mutant that contains a constitutively (constantly) active histone deacetylase. What phenotype do you predict for this mutant?

Mammals have a family between 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons. If all mammals have these genes, why do some mammals have a better sense of smell than others do?

Histone acetyl transferases exert their effect on gene activity by ________.

In eukaryotes, the normal or default state is that genes are turned ________.

Several of the different globin genes are expressed in humans but at different times in development. What mechanism could allow for this?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

Filters