BRAINSCAPE1
BIOL 2100 Exam 5 Exam with
complete solutions latest version
which of the following molecules binds to a repressor so that the repressor no longer
binds to an operator?
a) co-repressor
b) inducer
c) promoter
d) cAMP - CORRECT ANSWER-b) inducer
under which condition do high levels of transcription occur at an operon encoding
proteins required for catabolism of some molecule?
a) when a pathway's product accumulates
b) when an initial substrate is present
c) such operons are expected to be constitutive - CORRECT ANSWER-b) when an
initial substrate is present
which of the following changes in conditions results in an increase in CAP/CRP
mediated initiation of transcription?
a) an increase in glucose uptake and an increase in the repressor
b) a decrease in glucose uptake and an increase in cAMP
c) an increase in glucose uptake and a decrease in cAMP
d) a decrease in glucose uptake and a decrease in the repressor - CORRECT
ANSWER-b) a decrease in glucose uptake and an increase in cAMP
according to the lac operon model proposed by jacob and monod, what is predicted to
occur if the operator is removed from the operon?
a) the lac operon would be transcribed even in the absence of lactose
b) only lacZ would be transcribed
c) only lacY would be transcribed
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d) neither lacZ nor lacY would be transcribed - CORRECT ANSWER-a) the lac operon
would be transcribed even in the absence of lactose
which of the following statements correctly describes the primary difference between
enhancers and proximal control elements?
a) enhancers are transcription factors; proximal control elements are DNA sequences
b) enhancers improve transcription; proximal control elements inhibit transcription
c) enhancers are located considerable distances from the promoter; proximal control
elements are close to the promoter
d) enhancers are long regions of DNA; proximal control elements are shorter RNA
molecules that stand in for DNA - CORRECT ANSWER-c) enhancers are located
considerable distances from the promoter; proximal control elements are close to the
promoter
which of the following best explains why a neuron and a pancreatic cell isolated from
the same individual contain different sets of proteins?
a) the set of genes in each cell type are different, therefore, they express different
proteins
b) each cell type needs different proteins and, therefore, they break down proteins they
don't need
c) each cell type contains different regulatory proteins and, therefore, they express
different proteins
d) the genes in each cell type have different promoters and, therefore, they respond to
different regulatory proteins - CORRECT ANSWER-c) each cell type contains different
regulatory proteins and, therefore, they express different proteins
which of the following methods are used by eukaryotes to control gene expression but
are not used by bacteria?
a) organization of genes in operons
b) limiting access to free nucleotides
c) regulatory proteins binding to promoters and adjacent sequences
d) control of RNA splicing and chromatin remodeling - CORRECT ANSWER-d) control
of RNA splicing and chromatin remodeling
a researcher introduced many copies of a double-stranded RNA into a culture of
mammalian cells and used a florescent probe to follow it. later she finds that the
introduced strands separate into single-stranded RNAs and she hypothesizes that the
molecules is acting as an miRNA. which of the following pieces of evidence would
support her claim?
a) the degradation rate of the single strand is slower than that of other cellular mRNAs
b) the rate of accumulation of the polypeptide encoded by the target mRNA is reduced
c) the amount of the RNA she introduced increases due to transcription
BRAINSCAPE1
BIOL 2100 Exam 5 Exam with
complete solutions latest version
which of the following molecules binds to a repressor so that the repressor no longer
binds to an operator?
a) co-repressor
b) inducer
c) promoter
d) cAMP - CORRECT ANSWER-b) inducer
under which condition do high levels of transcription occur at an operon encoding
proteins required for catabolism of some molecule?
a) when a pathway's product accumulates
b) when an initial substrate is present
c) such operons are expected to be constitutive - CORRECT ANSWER-b) when an
initial substrate is present
which of the following changes in conditions results in an increase in CAP/CRP
mediated initiation of transcription?
a) an increase in glucose uptake and an increase in the repressor
b) a decrease in glucose uptake and an increase in cAMP
c) an increase in glucose uptake and a decrease in cAMP
d) a decrease in glucose uptake and a decrease in the repressor - CORRECT
ANSWER-b) a decrease in glucose uptake and an increase in cAMP
according to the lac operon model proposed by jacob and monod, what is predicted to
occur if the operator is removed from the operon?
a) the lac operon would be transcribed even in the absence of lactose
b) only lacZ would be transcribed
c) only lacY would be transcribed
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, BRAINSCAPE1
d) neither lacZ nor lacY would be transcribed - CORRECT ANSWER-a) the lac operon
would be transcribed even in the absence of lactose
which of the following statements correctly describes the primary difference between
enhancers and proximal control elements?
a) enhancers are transcription factors; proximal control elements are DNA sequences
b) enhancers improve transcription; proximal control elements inhibit transcription
c) enhancers are located considerable distances from the promoter; proximal control
elements are close to the promoter
d) enhancers are long regions of DNA; proximal control elements are shorter RNA
molecules that stand in for DNA - CORRECT ANSWER-c) enhancers are located
considerable distances from the promoter; proximal control elements are close to the
promoter
which of the following best explains why a neuron and a pancreatic cell isolated from
the same individual contain different sets of proteins?
a) the set of genes in each cell type are different, therefore, they express different
proteins
b) each cell type needs different proteins and, therefore, they break down proteins they
don't need
c) each cell type contains different regulatory proteins and, therefore, they express
different proteins
d) the genes in each cell type have different promoters and, therefore, they respond to
different regulatory proteins - CORRECT ANSWER-c) each cell type contains different
regulatory proteins and, therefore, they express different proteins
which of the following methods are used by eukaryotes to control gene expression but
are not used by bacteria?
a) organization of genes in operons
b) limiting access to free nucleotides
c) regulatory proteins binding to promoters and adjacent sequences
d) control of RNA splicing and chromatin remodeling - CORRECT ANSWER-d) control
of RNA splicing and chromatin remodeling
a researcher introduced many copies of a double-stranded RNA into a culture of
mammalian cells and used a florescent probe to follow it. later she finds that the
introduced strands separate into single-stranded RNAs and she hypothesizes that the
molecules is acting as an miRNA. which of the following pieces of evidence would
support her claim?
a) the degradation rate of the single strand is slower than that of other cellular mRNAs
b) the rate of accumulation of the polypeptide encoded by the target mRNA is reduced
c) the amount of the RNA she introduced increases due to transcription
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