Deck 12: Control of Gene Expression

Question 1

What is the name of the linkage than holds the lactose disaccharide together?

A) $\alpha$ -galactoside linkage
B) $\beta$ -lipophilic linkage
C) $\beta$ -glycosidic linkage
D) $\beta$ -galactoside linkage
E)ester linkage

Answer 1

$\beta$ -galactoside linkage

Question 2

What is probably the single most important distinction between prokaryotes and eukaryotes?

A)the existence of the Golgi complex
B)the separation of the cell's genetic material from the surrounding cytoplasm
C)the existence of ribosomes
D)the centrioles
E)the lysosomes and peroxisomes

Answer 2

B

Question 3

What is the name of the proteins that make up the nuclear lamina and of what protein superfamily are they a member?

A)lamins,laminins
B)lamins,intermediate filaments
C)keratin,intermediate filaments
D)keratin,laminins
E)actin,microfilaments

Answer 3

B

Question 4

With what structure is the outer membrane of the nuclear envelope continuous?

A)RER
B)SER
C)Golgi complex
D)the spindle
E)the plasma membrane

Question 5

The type of control exercised if the interaction of a regulatory protein and DNA inhibits transcription.

A)positive control
B)negative control
C)averaged control
D)circumspect control
E)neutral control

Question 6

Which of the traits below is characteristic of the classical nuclear localization signals?

A)possession of large numbers of hydrophobic amino acids
B)possession of one or two short stretches of negatively charged amino acids
C)possession of one or two short stretches of positively charged amino acids
D)twisted backbones
E)double helical regions

Question 7

The thin filamentous meshwork within the nucleus that is bound by integral membrane proteins of the inner surface of the nuclear envelope in animal cells is called the _________.

A)basement lamina
B)basal lamina
C)nuclear lamina
D)nucleon
E)nuclear limulus

Question 8

To what is the NLS - protein cargo - importing $\alpha$ / $\beta$ complex thought to bind when it seems to dock to the outer surface of the nucleus near the nuclear pore complex?

A)the torus
B)the outer ring of the nuclear pore complex
C)the inner ring of the nuclear pore complex
D)cytoplasmic filaments that extend from the outer ring of the nuclear pore complex
E)the transporter

Question 9

What site on a bacterial operon segment of a chromosome is adjacent to or overlaps with a promoter?

A)operator
B)terminator
C)activator
D)repressor
E)structural genes

Question 10

A transport receptor that moves macromolecules from the cytoplasm to the nucleus is called a(n)____.

A)exhalin
B)exportin
C)importin
D)transportin
E)receptin

Question 11

The operator __________.

A)is the site on the DNA where the repressor binds
B)is the site on the DNA where DNA polymerase binds
C)is the site on the DNA where reverse transcriptase binds
D)is the site on the RNA where the repressor binds
E)is the site on the ribosome where the repressor binds

Question 12

Which of the following words or phrases does not accurately describe the contents of the nucleus?

A)viscous
B)amorphous
C)undistinguished morphology
D)crystalline
E)highly extended nucleoprotein

Question 13

What is the name of the site where RNA polymerase binds to the DNA prior to the beginning of transcription?

A)the operator
B)the terminator
C)the promoter
D)the repressor
E)the structural genes

Question 14

$\beta$ -galactosidase is encoded by the ___________.

A)y gene of the lac operon
B)z gene of the lac operon
C)a gene of the lac operon
D)y gene of the trp operon
E)z gene of the trp operon

Question 15

Which of the following is not included within the nucleus of a typical interphase (nonmitotic)cell?

A)chromosomes
B)nuclear matrix
C)nucleolus
D)nucleoplasm
E)mesosome

Question 16

What two monosaccharides combine to form lactose?

A)2 glucose molecules
B)glucose and galactose
C)galactose and fructose
D)2 galactose molecules
E)glucose and fructose

Question 17

A section of a bacterial chromosome in which genes for the enzymes of a particular metabolic pathway are clustered together in a functional complex under coordinate control is called a(n)______.

A)operator
B)operon
C)promoter
D)repressor
E)activator

Question 18

The lac operon is an example of a(n)_______ operon.

A)noninducible
B)constitutive
C)inducible
D)repressible
E)irrepressible

Question 19

What is a regulatory protein for a gene? It binds to specific DNA sequences with high affinity and plays a predominant role in determining if a genome segment is transcribed or not.

A)the operator
B)the terminator
C)the promoter
D)the repressor
E)the structural genes

Question 20

How do allolactose and lactose differ?

A)They are composed of different sugars.
B)Allolactose has a negative charge,while lactose has a positive charge.
C)The type of linkage holding the two constituent sugars together differs between lactose and allolactose.
D)The order of the sugars is reversed in the two molecules.
E)The constituent sugars are both upside down in lactose and right-side-up in allolactose.

Question 21

An unusual stretch of repeated sequences at the tips of a DNA molecule forming a cap at each end of the chromosome is called a ________.

A)telomere
B)chromomere
C)centromere
D)telophase
E)karyomere

Question 22

Why was it initially expected that cloned animals might have a shorter life span?

A)The chromosomes of the donor nuclei had shortened telomeres.
B)The chromosomes of the donor nuclei had lengthened telomeres.
C)The egg cell had elevated telomerase.
D)The donor cell had elevated telomerase.
E)After transplant of the nucleus,telomerase levels climbed precipitously.

Question 23

What is used to maintain the Ran-GTP gradient across the nuclear envelope?

A)energy released by ATP hydrolysis
B)a proton gradient
C)a H⁺ ion gradient
D)energy released by GTP hydrolysis
E)energy released by GDP hydrolysis

Question 24

Which of the following is not a general description of the gene expression regulation mechanisms that operate in eukaryotic organisms?

A)transcriptional-level controls
B)processing-level controls
C)translational-level controls
D)replication-level controls
E)denaturation-level controls

Question 25

Which of the following would be the most acceptable explanation for why cloned animals actually have telomeres of normal length on their chromosomes?

A)The telomeres were elongated before transfer to the egg by telomerase in egg cell cytoplasm.
B)The telomeres were elongated after transfer to the egg by telomerase in egg cell cytoplasm.
C)The telomeres were shortened before transfer to the egg by telomerase in egg cell cytoplasm.
D)The telomeres were shortened after transfer to the egg by telomerase in egg cell cytoplasm.
E)The telomeres were replaced prior to mitosis by DNA repair.

Question 26

What evidence suggests that while the XIST gene may be required to initiate X chromosome inactivation,it may not be required to maintain it from one generation to another?

A)Tumor cells do not maintain X chromosome inactivation from generation to generation.
B)Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been deleted.
C)Some tumor cells in women contain inactivated X chromosomes whose XIST gene has been duplicated.
D)Some women have patches of cells in their retinas that are color blind and others that are not.
E)Some tumor cells in women have no X chromosomes.

Question 27

Genes are physically moved to sites within the nucleus called _________,where the transcription machinery is concentrated and within which genes involved in the same response tend to become colocalized.

A)transcription homes
B)transcription sites
C)transcription factories
D)translation factories
E)nucleosynthetic locales

Question 28

What is thought to maintain X chromosome inactivation?

A)repressive histone modifications
B)RNA inactivation
C)DNA methylation
D)localized DNA denaturation
E)both repressive histone modifications and DNA methylation

Question 29

What experimental evidence suggests that the N-terminal tails of histones participate in the formation of higher-order chromatin structure?

A)The tails cause histones to denature.
B)The tails when acetylated cause the dissolution of the 30-nm fibers.
C)Chromatin fibers prepared with H4 histones lacking their tails cannot fold into higher-order fibers.
D)Chromatin fibers prepared with H4 histones possessing longer tails cannot fold into higher-order fibers.
E)Chromatin fibers lacking tails are shorter.

Question 30

What is the name of the gene that makes the RNA thought to be responsible for the inactivation if the X chromosome?

A)INAC
B)XIST
C)1STX
D)IRS
E)XCHR

Question 31

The fact that chromosomes should become shorter and shorter with each round of cell division is referred to as the ________.

A)shortening contradiction
B)the replication paradox
C)the short end hypothesis
D)the truncated end problem
E)the end-replication problem

Question 32

There are genes on the X chromosome that manage to escape inactivation by an as yet unknown mechanism.What particular genes are included in this group and what might be the reason that they remain activated?

A)genes that are missing from the X chromosome; they will be expressed equally in both sexes
B)genes that are also present on the Y chromosome; they will be expressed equally in both sexes
C)genes that are also found on Chromosome 1; they will be expressed equally in both sexes
D)centromere genes; so that all cells will be able to attach to the spindle
E)centromere genes; they will be expressed equally in both sexes

Question 33

What evidence suggests that RNAi plays a role in heterochromatization?

A)Deletion of RNAi components impair both methylation of histone H3K9 and heterochromatization.
B)Addition of RNAi components impair both methylation of histone H3K9 and heterochromatization.
C)Deletion of RNAi components enhances both methylation of histone H3K9 and heterochromatization.
D)Mutation of RNAi components denatures both methylation of histone H3K9 and heterochromatization.
E)None of these are correct.

Question 34

If cells cannot replicate the ends of their DNA,what should happen with each round of cell division?

A)The chromosomes should stay exactly the same length.
B)The chromosomes should get longer.
C)The mitotic spindle will shrink.
D)The chromosomes should get shorter.
E)The chromosomes should denature.

Question 35

What level of control of gene expression is defined as regulating whether or not a particular mRNA is actually used in protein synthesis and,if so,how long and for how long a period of time?

A)transcriptional-level controls
B)processing-level controls
C)translational-level controls
D)replication-level controls
E)denaturation-level controls

Question 36

What distinguishes the regulatory,noncoding RNA that is suspected of being responsible for X chromosome inactivation from other noncoding RNA molecules?

A)It is much larger than the other noncoding RNAs.
B)It is much smaller than the other noncoding RNAs.
C)It is more tightly coiled than the other noncoding RNAs.
D)It contains a higher content of uracil than the other noncoding RNAs.
E)It contains a higher content of adenine than the other noncoding RNAs.

Question 37

Which level of control of gene expression is defined as determining if a particular gene can give rise to mRNA and,if so,how often?

A)transcriptional-level controls
B)processing-level controls
C)translational-level controls
D)replication-level controls
E)denaturation-level controls

Question 38

What is the advantage of the highly condensed state of the DNA of mitotic chromosomes?

A)This state allows gene expression needed during mitosis.
B)The highly condensed state favors delivery of an intact package of DNA to each daughter cell.
C)The condensed state allows chromosomes to fuse more easily.
D)The condensed state allows replication to occur more rapidly as the cell enters mitosis.
E)The condensed state favors DNA repair prior to mitosis.

Question 39

What happens if histone H1 is selectively extracted from compacted chromatin (30 nm fibers)?

A)30-nm fibers uncoil to form a thinner,more extended beaded filament.
B)30-nm fibers coil to form a thicker,less extended cylindrical filament.
C)30-nm fibers completely disassemble to their component nucleotides.
D)30-nm fibers break into small fragments.
E)30-nm fibers break up into large fragments.

Question 40

Scientists often stain chromosomes from mitotic cells and photograph the chromosomes in the microscope.Each chromosome is cut out of the photograph,the chromosomes are matched up in homologous pairs and they are placed in order of decreasing size.These pictures can be used to screen individuals for chromosomal abnormalities,like extra,missing or grossly altered chromosomes.What is such a picture called?

A)karyoplan
B)eukaryote
C)karyotype
D)karyokinesis
E)prokaryote

Question 41

Each transcription factor usually has at least two domains that mediate different aspects of their function.What are they?

A)the DNA-binding domain and the activation domain
B)the activation domain and the repression domain
C)the DNA-binding domain and the repression domain
D)the RNA-binding domain and the activation domain
E)the RNA-binding domain and the repression domain

Question 42

The combination of a basic stretch of amino acids and a leucine zipper is known as a(n)_____ motif.

A)bHLH
B)bZip
C)acidic zipper
D)basic zipper
E)basido zipper

Question 43

Which type of molecule binds at the core promoter sites in association with RNA polymerase?

A)general transcription factors
B)sequence-specific transcription factors
C)elongation factors
D)initiation factors
E)termination factors

Question 44

You attempt deletion mapping of a part of the promoter region of a particular gene.You remove a short sequence of nucleotides.Once the altered DNA is transfected into cells,the cells are able to transcribe the transfected DNA in a normal fashion.What do you conclude?

A)The sequence that was removed is an essential part of the promoter.
B)The sequence that was deleted is an important determinant of the ability to transcribe the gene.
C)The sequence that was removed is not an essential part of the promoter.
D)The deleted sequence has a moderate level of importance in promoting transcription.
E)The deleted sequence binds tightly to RNA polymerase.

Question 45

Transcription factors bound at the enhancer stimulate the initiation of transcription at the core promoter through the action of intermediaries called _____.

A)corepressors
B)cotranscriptors
C)coactivators
D)preinitiators
E)costimulators

Question 46

You are interpreting data on a DNA chip or microarray.You expose the chip to a mixture of two cDNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls; labeled with a red fluorescent dye)and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labeled with green fluorescent dye).You look at a spot on the chip representing the gene for phosphofructokinase,a gene that is not affected by glucocorticoid treatment,but is instead expressed in all cells.What color should the spot representing the phosphofructokinase gene be?

A)red
B)green
C)yellow
D)no color,the spot is not labeled
E)brown

Question 47

Which transcription factor helps to activate genes needed for cell division?

A)Egr
B)Csn
C)GATA
D)GATO
E)espn

Question 48

Treatment of fragmented DNA with a particular transcription factor attached at a number of sites with antibodies against that transcription factor will cause _________.

A)precipitation of DNA fragments bound to that transcription factor
B)solubilization of DNA fragments bound to that transcription factor
C)hydrolysis of DNA fragments bound to that transcription factor
D)hydrolysis of DNA fragments that remain unbound by that transcription factor
E)precipitation of DNA fragments not bound to that transcription factor

Question 49

The extent to which a given gene is transcribed presumably depends upon __________.

A)the single transcription factor bound to its upstream regulatory elements
B)the particular combination of transcription factors bound to its upstream regulatory elements
C)the particular combination of transcription factors bound to its downstream regulatory elements
D)the combination of initiation factors bound to its upstream regulatory elements
E)the combination of translational factors bound to its upstream regulatory elements

Question 50

The basic amino acid stretch in bZip proteins _______.

A)facilitates dimerization
B)allows the protein to recognize a specific nucleotide sequence in DNA
C)prevents dimerization
D)allows the protein to recognize a specific nucleotide sequence in RNA
E)facilitates tetramerization

Question 51

When DNA-binding proteins are removed from immunoprecipitated DNA sequences and the DNA fragments precipitated by the antibody are subsequently sequenced directly to determine the genomic sites bound,the technique is called __________.

A)Hip-chip
B)ChIP-chip
C)ChIP-seq
D)chromatin immunoprecipitation
E)ChIP

Question 52

You are interpreting data on a DNA chip or microarray.You expose the chip to a mixture of two cDNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls; labeled with a red fluorescent dye)and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labeled with green fluorescent dye).You look at a spot on the chip representing the gene for phosphoenolase,a gene that is turned off by glucocorticoid treatment,but is expressed in control,untreated cells.What color should the spot representing the phosphoenolase gene be?

A)red
B)green
C)yellow
D)no color,the spot is not labeled
E)brown

Question 53

The HLH motif is often preceded by a stretch of highly ______ amino acids whose ______ charged side chains contact DNA and determine the transcription factor's sequence specificity.

A)basic,positively
B)basic,negatively
C)acidic,negatively
D)acidic,positively
E)hydrophobic,neutral

Question 54

What domain of a transcription factor is responsible for recognizing and associating with specific DNA base pair sequences?

A)the DNA-binding domain
B)the activation domain
C)the repression domain
D)the DNA-unwinding domain
E)the DNA-derepression domain

Question 55

Which of the following is not a transcription factor identified as important for maintaining pluripotency in ES cells?

A)Oct4
B)Myc
C)Cal5
D)Sox2
E)Klf4

Question 56

What strategy in transcription factor research allows the simultaneous monitoring of all sites in the genome that carry out a particular activity with the goal of identifying all of the sites bound by a given transcription factor under a given set of physiological conditions?

A)deletion mapping
B)DNA footprinting
C)genome-wide location analysis
D)FISH
E)scanning electron microscopy

Question 57

The $\alpha$ -helical portions of the bZip proteins ______.

A)facilitate dimerization
B)allow the protein to recognize a specific nucleotide sequence in DNA
C)prevent dimerization
D)allow the protein to recognize a specific nucleotide sequence in RNA
E)facilitate tetramerization

Question 58

When present,the TATA,CAAT and GC boxes are typically found within 100 - 150 bp upstream from the transcription start site.Due to their closeness to the start of gene,they are often called ______.

A)distal promoter elements
B)proximal promoter elements
C)central promoter sites
D)primary promoter elements
E)primary promoter sites

Question 59

You are working with adult mouse fibroblast cells.The genes for transcription factors from pluripotent stem cells are transduced into the adult fibroblast cells as part of viral vectors in various combinations,and once inside the cells they were expressed.Cells are produced that are capable of dividing indefinitely in culture and of differentiating into all of the various types of the body's cells.What are they called?

A)iPS cells
B)white blood cells
C)induced pluripotent cells
D)infracted pluripotent cells
E)both iPS cells and induced pluripotent cells

Question 60

What phenomenon greatly expands the diversity of regulatory factors that can be generated from a limited number of polypeptides?

A)heterodimerization
B)homodimerization
C)heterohomodimerization
D)recombination
E)heterotrimerization

Question 61

A complex of exonucleases that degrades mRNAs is called the ______.

A)endosome
B)execrosome
C)exosome
D)enterosome
E)edusome

Question 62

What extends from the termination codon at the end of an mRNA coding region to the end of the poly(A)tail?

A)the first intron
B)the last exon
C)the 5' UTR
D)the 3' UTR
E)the last intron

Question 63

What extends from the methylguanosine cap at the start of an mRNA to the AUG initiation codon?

A)the first intron
B)the last exon
C)the 5' UTR
D)the 3' UTR
E)the last intron

Question 64

If an exon is not supposed to be included in the mature mRNA,it must be excised.With what other RNA sequences is it excised?

A)the flanking exons
B)the flanking introns
C)one flanking exon and one flanking intron
D)the promoter
E)the poly(A)sequence

Question 65

Why does the activation of a protein kinase that acts on initiation factor eIF2 block protein synthesis?

A)Phosphorylated eIF2 denatures.
B)Phosphorylated eIF2 cannot exchange its GDP for GTP,which is required for eIF2 to participate in another round of translation initiation.
C)Phosphorylated eIF2 cannot exchange its GTP for GDP,which is required for eIF2 to participate in another round of translation initiation.
D)Phosphorylated eIF2 is hyperactivated,blocking further translation.
E)Dephosphorylated eIF2 cannot exchange its GDP for GTP,which is required for eIF2 to participate in another round of translation initiation.

Question 66

What role are microfilaments thought to play in the localization of oskar and bicoid mRNAs in the fruit fly oocytes?

A)They are thought to anchor mRNAs in position after they have arrived at their destination.
B)They move these mRNAs to their final destination.
C)They play no role in localization or anchoring the mRNAs in the proper position.
D)They compress the mRNAs.
E)They increase the stability of mRNAs.

Question 67

Evidence suggests that _____ of ______ from nucleosomes in the wake of an elongating RNA polymerase prevents the inappropriate __________ within the internal coding region of a gene.

A)addition,acetyl groups,initiation of transcription
B)removal,acetyl groups,initiation of translation
C)removal,acetyl groups,initiation of transcription
D)removal,methyl groups,initiation of transcription
E)addition,methyl groups,initiation of translation

Question 68

What evidence would suggest that histone acetylation provides a recognizable surface to recruit proteins that bind to acetylated histones?

A)Mutation of a lysine in the tail of histone H3 in a promoter region to an alanine,which cannot be acetylated,prevents the binding of transcription factors that normally bind to that promoter.
B)Lysines interfere with the binding of transcription factors to histone H3K9.
C)Alanines bind to transcription factors very tightly.
D)Histone H3K9 cannot be acetylated and therefore does not bind transcription factors.
E)Acetylation of histone H3K9 inhibits binding of transcription factors.

Question 69

What is the normal length of a poly(A)tail?

A)about 100 adenosine residues
B)about 500 adenosine residues
C)about 200 adenosine residues
D)about 1000 adenosine residues
E)about 700 adenosine residues

Question 70

The enzymes that remove acetyl groups from histones in the chromatin are ________.

A)histone acetyltransferases
B)histone deacetylases
C)histone acetylases
D)histone methylases
E)methylacetyltransferases

Question 71

_______ mRNAs are preferentially localized at the anterior end of a fruit fly larva; ______ mRNAs are preferentially localized at the opposite or posterior end of the larva.

A)Bicoid,oskar
B)Oskar,bicoid
C)Bicoid,staufen
D)Staufen,bicoid
E)Oskar,staufen

Question 72

The localization of mRNAs is mediated by specific proteins that recognize mRNA localization sequences on the mRNAs.What name has been given to these sequences?

A)mRNA localizers
B)localicodes
C)zip-codes
D)ziptrons
E)zaptronics

Question 73

In mRNA editing,to which nitrogenous bases is adenine converted by the enzymatic removal of an amino group?

A)cytosine
B)inosine
C)guanine
D)thymine
E)uracil

Question 74

The oskar protein is required for the ________,which develop at the _______ end of the larva.

A)formation of germ cells,anterior
B)formation of germ cells,posterior
C)formation of muscle cells,anterior
D)formation of osteocytes,posterior
E)formation of brain cells,anterior

Question 75

The inactive mRNAs that are stored in an egg prior to fertilization typically have ________.

A)lenghtened 5' UTRs
B)lenghtened poly(A)tails
C)shortened poly(A)tails
D)many lipids associated with them
E)shortened 5' UTRs

Question 76

Which genetic phenomenon below involves the conversion of specific nucleotides to other nucleotides after RNA has been transcribed?

A)translational frameshifting
B)termination codon readthrough
C)mRNA editing
D)alternative translation initiation
E)translational bypassing

Question 77

Mechanisms have been discovered that regulate the rate of mRNA translation in response to changing cellular requirements; these mechanism can act at both the ______ and ______ levels.

A)individual,evolutionary
B)global,invidious
C)global,specific
D)evolutionary,global
E)specific,evolutionary

Question 78

Why might localizing mRNAs in the oocyte be more efficient than localizing the proteins they encode?

A)Messenger RNAs are easier to move than proteins.
B)Each mRNA can be translated into a limited number of proteins.
C)Each mRNA can be translated into a large number of proteins.
D)Messenger RNAs are easier to immobilize than proteins.
E)Localizing proteins would denature them.

Question 79

Messenger RNA editing is an example of gene expression at the _________ level.

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

Question 80

How short must the poly(A)tail get to cause the mRNA to be degraded rapidly?

A)1 adenosine residue
B)about 10 adenosine residues
C)about 100 adenosine residues
D)about 30 adenosine residues
E)about 75 adenosine residues