Exam 3- BIOS252 BIOS 252 (Latest 2025 UPDATED) Anatomy And
Physiology II With Lab - Chamberlain
Which term would be applied to a regulatory condition that occurs when protein is associated
with a particular section of DNA and greatly reduces transcription? - (ANSWER)negative
control
In the diagram below, what type of control, positive or negative, is operating?
-{ }( )-|-structrual gene-
^
{regulatory protien}
makes a transcription. - (ANSWER)positive control
T/F Under a system of positive control, transcription does not occur unless a regulator molecule
directly stimulates RNA production. - (ANSWER)True
T/F Under a system of negative control, genetic expression occurs unless some form of regulator
你是想要一篇“眼睛容易阅读的”
shuts off such expression. - (ANSWER)True
中文文章，还是一篇关于“眼睛”
主题的中文文章？
Which term is used to describe enzymes that are produced only when specific substrates are
present in the environment? - (ANSWER)inducible: This term best describes enzymes that are
produced only when specific substrates are present in the environment to induce their production.
Which term refers to a contiguous genetic complex that is under coordinated control? -
(ANSWER)operon
Things to define - (ANSWER)allosteric
lysogen
attenuation
,prototroph
operon
Cryan experiments with gut microbes
16 interaction
17 interaction
Which of the following mutations could lead to constitutive expression of the genes of the lac
operon? - (ANSWER)A mutation in the operator sequence. Such a mutation could prevent
binding of the repressor, allowing expression under all conditions.
Which of the following best describes the biological role of the lac operon? - (ANSWER)It
ensures that a cell dedicates resources to the production of enzymes involved in lactose
metabolism only when lactose is available in the environment. The cell expends energy to
produce the proteins necessary for lactose metabolism only when lactose is present.
T/F The placement of the operator sequence between the promotor and the structural genes is
critical to the proper function of the lac operon. - (ANSWER)True. When the repressor binds to
the operator, RNA polymerase cannot transcribe the structural genes.
你是想要一篇“眼睛容易阅读的”
In the lac operon, the product of structural gene lacZ is capable of ________. -
中文文章，还是一篇关于“眼睛”
(ANSWER)splitting the β-linkage of lactose
主题的中文文章？
Which term most appropriately refers to a regulatory protein in prokaryotes? - (ANSWER)DNA
binding protein
A constitutive mutation in the lac operon may be of several types. Name two types of
constitutive mutations. - (ANSWER)lacOc, lacI-
T/F Regarding the lactose utilization system in E. coli, a constitutive mutant is one in which the
three enzymes are produced regardless of the presence or absence of lactose. - (ANSWER)True
Which of the following is a neurochemical microbes in our gut can make? - (ANSWER)GABA
,Experiments led by Cryan's group found that - (ANSWER)Mice fed lactobacilllus were more
calm, behaviorally, when measured via a 6 minutes swim test.
When Lyte asked, "Can bacteria cause stress in mice?" he did an experiment that measured: -
(ANSWER)how mice approached ledges of a maze
T/F Dr. Lyte's inital experiments linking the microbiome to behavior were immediately ground-
breaking and game-changing for the field. - (ANSWER)False
Which of the following terms best characterizes catabolite repression associated with the lac
operon in E. coli? - (ANSWER)positive control
T/F Lactose is an inducer of the lac operon. - (ANSWER)True. Lactose indirectly induces or
stimulates the transcription of genes involved in its metabolism.
What would be the effect of a mutation in the lacI gene that prevented the repressor from binding
to lactose? - (ANSWER)The lac Z, Y, and A genes would not be expressed. If lactose could not
bind to the repressor, the repressor would stay bound to the operator and repress the transcription
of the lac Z, Y, and A genes. 你是想要一篇“眼睛容易阅读的”
中文文章，还是一篇关于“眼睛”
What is the role of glucose in主题的中文文章？
catabolite repression? - (ANSWER)It decreases the levels of
cAMP in the cell, repressing transcription from the lac operon.Glucose decreases the levels of
cAMP in the cell, preventing formation of the CAP-cAMP complexes necessary for the
stimulation of transcription from the lac operon.
For the genotype,
I + O+ Z+/ F' I - O+ Z+
which of the following should be entered into the chart?
Genotype
I + O+ Z+/ F' I - O+ Z+
, I - Oc Z+/ F'I - O+ Z-
I s Oc Z+/ F'I + O+ Z+
I - O+ Z+/ F' I - O+ Z+
I+ = wild-type repressor
I- = mutant repressor (unable to bind to the operator)
Is = mutant repressor (insensitive to lactose)
O+ = wild-type operator
Oc = constitutive operator (insensitive to repressor)
lactose or no lactose in chart - (ANSWER)- + (beta gal made when there is lactose)
For the genotype,
I - Oc Z+/ F'I - O+ Z-
which of the following should be entered into the chart?
Genotype
I + O+ Z+/ F' I - O+ Z+ 你是想要一篇“眼睛容易阅读的”
I - Oc Z+/ F'I - O+ Z- 中文文章，还是一篇关于“眼睛”
I s Oc Z+/ F'I + O+ Z+ 主题的中文文章？
I - O+ Z+/ F' I - O+ Z+
I+ = wild-type repressor
I- = mutant repressor (unable to bind to the operator)
Is = mutant repressor (insensitive to lactose)
O+ = wild-type operator
Oc = constitutive operator (insensitive to repressor)
lactose or no lactose in chart - (ANSWER)+ +
Physiology II With Lab - Chamberlain
Which term would be applied to a regulatory condition that occurs when protein is associated
with a particular section of DNA and greatly reduces transcription? - (ANSWER)negative
control
In the diagram below, what type of control, positive or negative, is operating?
-{ }( )-|-structrual gene-
^
{regulatory protien}
makes a transcription. - (ANSWER)positive control
T/F Under a system of positive control, transcription does not occur unless a regulator molecule
directly stimulates RNA production. - (ANSWER)True
T/F Under a system of negative control, genetic expression occurs unless some form of regulator
你是想要一篇“眼睛容易阅读的”
shuts off such expression. - (ANSWER)True
中文文章，还是一篇关于“眼睛”
主题的中文文章？
Which term is used to describe enzymes that are produced only when specific substrates are
present in the environment? - (ANSWER)inducible: This term best describes enzymes that are
produced only when specific substrates are present in the environment to induce their production.
Which term refers to a contiguous genetic complex that is under coordinated control? -
(ANSWER)operon
Things to define - (ANSWER)allosteric
lysogen
attenuation
,prototroph
operon
Cryan experiments with gut microbes
16 interaction
17 interaction
Which of the following mutations could lead to constitutive expression of the genes of the lac
operon? - (ANSWER)A mutation in the operator sequence. Such a mutation could prevent
binding of the repressor, allowing expression under all conditions.
Which of the following best describes the biological role of the lac operon? - (ANSWER)It
ensures that a cell dedicates resources to the production of enzymes involved in lactose
metabolism only when lactose is available in the environment. The cell expends energy to
produce the proteins necessary for lactose metabolism only when lactose is present.
T/F The placement of the operator sequence between the promotor and the structural genes is
critical to the proper function of the lac operon. - (ANSWER)True. When the repressor binds to
the operator, RNA polymerase cannot transcribe the structural genes.
你是想要一篇“眼睛容易阅读的”
In the lac operon, the product of structural gene lacZ is capable of ________. -
中文文章，还是一篇关于“眼睛”
(ANSWER)splitting the β-linkage of lactose
主题的中文文章？
Which term most appropriately refers to a regulatory protein in prokaryotes? - (ANSWER)DNA
binding protein
A constitutive mutation in the lac operon may be of several types. Name two types of
constitutive mutations. - (ANSWER)lacOc, lacI-
T/F Regarding the lactose utilization system in E. coli, a constitutive mutant is one in which the
three enzymes are produced regardless of the presence or absence of lactose. - (ANSWER)True
Which of the following is a neurochemical microbes in our gut can make? - (ANSWER)GABA
,Experiments led by Cryan's group found that - (ANSWER)Mice fed lactobacilllus were more
calm, behaviorally, when measured via a 6 minutes swim test.
When Lyte asked, "Can bacteria cause stress in mice?" he did an experiment that measured: -
(ANSWER)how mice approached ledges of a maze
T/F Dr. Lyte's inital experiments linking the microbiome to behavior were immediately ground-
breaking and game-changing for the field. - (ANSWER)False
Which of the following terms best characterizes catabolite repression associated with the lac
operon in E. coli? - (ANSWER)positive control
T/F Lactose is an inducer of the lac operon. - (ANSWER)True. Lactose indirectly induces or
stimulates the transcription of genes involved in its metabolism.
What would be the effect of a mutation in the lacI gene that prevented the repressor from binding
to lactose? - (ANSWER)The lac Z, Y, and A genes would not be expressed. If lactose could not
bind to the repressor, the repressor would stay bound to the operator and repress the transcription
of the lac Z, Y, and A genes. 你是想要一篇“眼睛容易阅读的”
中文文章，还是一篇关于“眼睛”
What is the role of glucose in主题的中文文章？
catabolite repression? - (ANSWER)It decreases the levels of
cAMP in the cell, repressing transcription from the lac operon.Glucose decreases the levels of
cAMP in the cell, preventing formation of the CAP-cAMP complexes necessary for the
stimulation of transcription from the lac operon.
For the genotype,
I + O+ Z+/ F' I - O+ Z+
which of the following should be entered into the chart?
Genotype
I + O+ Z+/ F' I - O+ Z+
, I - Oc Z+/ F'I - O+ Z-
I s Oc Z+/ F'I + O+ Z+
I - O+ Z+/ F' I - O+ Z+
I+ = wild-type repressor
I- = mutant repressor (unable to bind to the operator)
Is = mutant repressor (insensitive to lactose)
O+ = wild-type operator
Oc = constitutive operator (insensitive to repressor)
lactose or no lactose in chart - (ANSWER)- + (beta gal made when there is lactose)
For the genotype,
I - Oc Z+/ F'I - O+ Z-
which of the following should be entered into the chart?
Genotype
I + O+ Z+/ F' I - O+ Z+ 你是想要一篇“眼睛容易阅读的”
I - Oc Z+/ F'I - O+ Z- 中文文章，还是一篇关于“眼睛”
I s Oc Z+/ F'I + O+ Z+ 主题的中文文章？
I - O+ Z+/ F' I - O+ Z+
I+ = wild-type repressor
I- = mutant repressor (unable to bind to the operator)
Is = mutant repressor (insensitive to lactose)
O+ = wild-type operator
Oc = constitutive operator (insensitive to repressor)
lactose or no lactose in chart - (ANSWER)+ +
