MCB 150 Quest #5 Questions With Complete Solutions
A mutation to lacI could result in a constitutively transcribed
operon. Correct Answers True
A mutation to the lacO site could result in a constitutively
transcribed operon Correct Answers True If you mutate the
operator in such a way that the repressor cannot bind it anymore,
this would mean that the genes will always be transcribed. If you
mutate the repressor in such a way that it cannot bind the
repressor anymore, then this would also result in genes that are
always transcribed.
A peptide must contain a sorting signal called an ER _______
________ to be directed to the ER membrane Correct Answers
signal sequence
Allolactose Correct Answers An inducer, a small effector
molecule that increases the rate of transcription, and the lac
operon is said to be an inducible operon
Alternative splicing Correct Answers Splicing of introns in a
pre-mRNA that occurs in different ways, leading to different
mRNAs that code for different proteins or protein isoforms.
Increases the diversity of proteins.
An example of a ncRNA during functioning as a ribozyme is the
RNA component of _______ Correct Answers
peptidyltransferase
,An immune type system in prokaryotes that protects against
foreign invaders is called the _______-_________ system
Correct Answers CRISPR Cas
An ncRNA that binds to a protein and brings it to a specific site
in the cell's DNA is performing what function? Correct Answers
Guide
An rRNA within peptidyltransferase acts as a ribozyme by
catalyzing the Correct Answers Formation of peptide bonds
during translation
Approximately how many human genes are estimated to encode
miRNAs? Correct Answers 2,000
At birth what genes are turned on/off? Correct Answers The y-
globin gene is turned off, and the beta B-globin (beta-globin)
gene is turned on
At the fetal stage, what genes are turned on? Correct Answers
The a-globin and y-globin (alpha and gamma)
Bacteriophage DNA is processed by Cas1 and Cas2, and is
incorporated as _______ in the crispr locus Correct Answers
spacers
Benefits of RNA interference Correct Answers -The production
of miRNAs silences the expression of specific mRNAs
-RNA interference provides a defense against viruses. This
mechanism is widely used by plants to prevent viral infections
,Blocker Correct Answers an ncRNA may physically prevent or
block a cellular process from happening
Blocker example Correct Answers In bacteria, an antisense
RNA is a type of ncRNA that is complementrary to an mRNA.
When an antisense RNA binds to an mRNA, it blocks the ability
of a ribosome to bind to the mRNA, inhibiting translation
By regulating RNA modification, eukaryotes can produce more
than one mRNA transcript from a single gene Correct Answers
This allows a gene to encode two or more polypeptides, thereby
increasing the complexity of eukaryotic proteomes
A second issue is timing (regulation of transcription in
eukaryotes takes a fair amount of time before its effects are
observed at the cellular level
Can histone modifications mediated by HOTAIR inhibit
transcription either directly or by attracting other chromatin-
modifying enzymes? Correct Answers True
CAP is controlled by a small effector molecule called.... Correct
Answers Cyclic AMP (cAMP), which is produced from ATP
via an enzyme known as adenylyl cyclase
CAP site Correct Answers A regulatory sequence recognized by
an activator protein
Cas9 induces _______ ______ breaks in bacteriophage DNA
Correct Answers double strand
, Catabolite repression Correct Answers The presence of a
preferred energy source inhibits the use of other energy sources
Cell differentiation Correct Answers The process by which cells
become specialized into particular types
Cell wall Correct Answers In plant cells: A network of
materials that is secreted from cells and forms a complex
meshwork outside of cells
Cis-acting element Correct Answers DNA segment that must be
adjacent to the gene that it regulates
-at the lac operon site
Cis-effect Correct Answers mediated by a cis-acting element
that binds regulatory proteins, whereas a tran-effect is mediated
by genes that encode diffusible regulatory proteins
closed conformation Correct Answers a tightly packed
conformation of chromatin that cannot be transcribed
Consider the following two reactions, where the // represents a
cut in the sequence:
Enzyme X: 5' GGGGGG//CCCCCC 3' 3' CCCCCC//GGGGGG
5'
Which of the following enzymes could be enzyme X? Select all
that apply. Correct Answers Dicer, cas9
-Enzyme X is an endonuclease (cleaves in the middle of the
sequence) specifically also acting on both strands. Cas9 is a
deoxyriboendonuclease that induces double stranded breaks in
the DNA of bacteriophage in order to prevent proliferation of
A mutation to lacI could result in a constitutively transcribed
operon. Correct Answers True
A mutation to the lacO site could result in a constitutively
transcribed operon Correct Answers True If you mutate the
operator in such a way that the repressor cannot bind it anymore,
this would mean that the genes will always be transcribed. If you
mutate the repressor in such a way that it cannot bind the
repressor anymore, then this would also result in genes that are
always transcribed.
A peptide must contain a sorting signal called an ER _______
________ to be directed to the ER membrane Correct Answers
signal sequence
Allolactose Correct Answers An inducer, a small effector
molecule that increases the rate of transcription, and the lac
operon is said to be an inducible operon
Alternative splicing Correct Answers Splicing of introns in a
pre-mRNA that occurs in different ways, leading to different
mRNAs that code for different proteins or protein isoforms.
Increases the diversity of proteins.
An example of a ncRNA during functioning as a ribozyme is the
RNA component of _______ Correct Answers
peptidyltransferase
,An immune type system in prokaryotes that protects against
foreign invaders is called the _______-_________ system
Correct Answers CRISPR Cas
An ncRNA that binds to a protein and brings it to a specific site
in the cell's DNA is performing what function? Correct Answers
Guide
An rRNA within peptidyltransferase acts as a ribozyme by
catalyzing the Correct Answers Formation of peptide bonds
during translation
Approximately how many human genes are estimated to encode
miRNAs? Correct Answers 2,000
At birth what genes are turned on/off? Correct Answers The y-
globin gene is turned off, and the beta B-globin (beta-globin)
gene is turned on
At the fetal stage, what genes are turned on? Correct Answers
The a-globin and y-globin (alpha and gamma)
Bacteriophage DNA is processed by Cas1 and Cas2, and is
incorporated as _______ in the crispr locus Correct Answers
spacers
Benefits of RNA interference Correct Answers -The production
of miRNAs silences the expression of specific mRNAs
-RNA interference provides a defense against viruses. This
mechanism is widely used by plants to prevent viral infections
,Blocker Correct Answers an ncRNA may physically prevent or
block a cellular process from happening
Blocker example Correct Answers In bacteria, an antisense
RNA is a type of ncRNA that is complementrary to an mRNA.
When an antisense RNA binds to an mRNA, it blocks the ability
of a ribosome to bind to the mRNA, inhibiting translation
By regulating RNA modification, eukaryotes can produce more
than one mRNA transcript from a single gene Correct Answers
This allows a gene to encode two or more polypeptides, thereby
increasing the complexity of eukaryotic proteomes
A second issue is timing (regulation of transcription in
eukaryotes takes a fair amount of time before its effects are
observed at the cellular level
Can histone modifications mediated by HOTAIR inhibit
transcription either directly or by attracting other chromatin-
modifying enzymes? Correct Answers True
CAP is controlled by a small effector molecule called.... Correct
Answers Cyclic AMP (cAMP), which is produced from ATP
via an enzyme known as adenylyl cyclase
CAP site Correct Answers A regulatory sequence recognized by
an activator protein
Cas9 induces _______ ______ breaks in bacteriophage DNA
Correct Answers double strand
, Catabolite repression Correct Answers The presence of a
preferred energy source inhibits the use of other energy sources
Cell differentiation Correct Answers The process by which cells
become specialized into particular types
Cell wall Correct Answers In plant cells: A network of
materials that is secreted from cells and forms a complex
meshwork outside of cells
Cis-acting element Correct Answers DNA segment that must be
adjacent to the gene that it regulates
-at the lac operon site
Cis-effect Correct Answers mediated by a cis-acting element
that binds regulatory proteins, whereas a tran-effect is mediated
by genes that encode diffusible regulatory proteins
closed conformation Correct Answers a tightly packed
conformation of chromatin that cannot be transcribed
Consider the following two reactions, where the // represents a
cut in the sequence:
Enzyme X: 5' GGGGGG//CCCCCC 3' 3' CCCCCC//GGGGGG
5'
Which of the following enzymes could be enzyme X? Select all
that apply. Correct Answers Dicer, cas9
-Enzyme X is an endonuclease (cleaves in the middle of the
sequence) specifically also acting on both strands. Cas9 is a
deoxyriboendonuclease that induces double stranded breaks in
the DNA of bacteriophage in order to prevent proliferation of
