chapter 14, 15, 16,17
False
DNA methylation usually activates gene expression.
H4
For which of the following histones has variant forms not yet been identified?
The trp operon would never be transcribed.
If the Trp codons in the trpL gene were mutated to encode another amino acid, what would the result be?
false
In maize red1' is a strongly expressed allele that is paramutable.
false
Prior to hormone binding, receptors for steroid hormones are usually found in the nucleus of the cell.
Binds to the mRNA and prevents translation
Antisense RNA does which of the following?
True
Constitutive genes are those that have constant levels of expression.
Tsix
Expression of ______ would inhibit X-inactivation.
Chemical modification of histones
Histone acetyltransferases are directly involved in which of the following?
False
Insulators exert their effects on gene expression through histone acetyltransferase, histone deacetylase, and RNA polymerase.
False
Methylation of DNA bases is one way that regulatory transcription factors may influence gene expression.
Igf-2
Most imprinted genes are silenced. What is one exception to this rule?
post translation, translation, transcription
Regulation of gene expression may occur at which of the following levels? (Check all that apply.) Post translation Constitutive expression Translation Transcription
true
Repressor proteins are responsible for negative transcriptional regulation.
True
Research suggests that the silencing of paramutagenic may involve short RNAs incorporated into RNA-induced silencing complexes.
True
The activity of some transcription factors can be regulated by covalent modifications.
true
The red1'allele is said to be paramutagenic, because it can change the expression of another allele.
post-translational regulation
The regulation of protein function is called __________.
true
The regulation of the CAP complex using cAMP is an example of inducible genetic regulation.
Phosphorylation
What activates CREB?
Xist
What gene is most responsible for X-inactivation?
the transcription will not be produced
A deletion in an operon removes the promoter. How will that affect the transcript that is produced from the operon?
The transcription will be produced but more longer than normal
A deletion in an operon removes the terminator. How will that affect the transcript that is produced from the operon?
respressor + inducer
A gene is inducible and under negative control. Which of the following pairs will allow expression of this gene?
false
A heterodimer occurs when two identical transcription factors interact on a sequence of DNA.
constitutive transferrin receptor and no ability to stimulate ferritin expression
A mutation in the iron response protein (IRP) that made it incapable of binding iron would result in __________.
No transcription
A mutation in the lacI gene prevents the gene product from binding allolactose. What will the expression level of the operon be in the absence of lactose?
Glucocorticoid receptor
A mutation in which of the following would result in little or no effect on the expression of a gene regulated by a CRE?
The cell will express different sets of genes than other cells in the same organism.
A particular cell contains all of the standard histones but lacks several histone variants. Which of the following MAY be true of this cell?
The expression of the gene would be abnormally low or absent.
A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene?
false
A repressor protein would enhance the ability of TFIID to bind to the TATA box of the promoter.
false
A riboswitch only affects translation of an operon.
False
A transactivation domain is an example of a motif found in transcription factors.
false
Activator proteins bind to silencer sequences and repressor proteins bind to enhancer sequences.
true
After the paramutable allele is altered, its expression is the same or similar to the paramutagenic allele.
a small molecule that fits into a site on the enzyme that is not the active site
Allosteric regulation is accomplished by __________.
positive control
An activator is present and results in the increase in transcription of the target gene. This is an example of _______________.
allosteric enzyme
An enzyme catalyzes a substrate into a final product. When the concentration of the final product is high enough, it binds to a regulatory site on the enzyme. This binding at the regulatory site changes the shape of the enzyme, which prevents it from binding the substrate and prevents formation of more final product. This is an example of a/an __________.
False
Arabidopsis, the FLC gene is necessary to promote flower development.
False
Both parents usually imprint the same gene.
True
Covalent histone modification is sometimes involved in cell differentiation.
DNA methylation
CpG islands are associated with which of the following?
false
DNA that contains actively transcribed genes would most likely contain chromatin in the closed configuration.
false
DNA that contains instructions for two or more structural genes produces monocistronic mRNA
feedback inhibition
Enzymes involved in metabolism are most likely regulated via __________.
All of these choices are correct.
Epigenetic inheritance may occur at which of the following stages?
B,C
Feeding a specific diet to female mice may result in an increased proportion of pseudoagouti offspring if __________. A) the female carries the Avy allele B) the offspring have the genotype Avya C) the transposon at the Avylocus in the progeny is hypermethylated
DNA methylation
Genomic imprinting is a result of ___________.
true
Housekeeping genes are unmethylated and active in most cells.
A,C,D
How are eukaryotic transcription factors regulated? (Check all that apply.) A) Covalent modification B) Binding to cytoskeletal elements C) Binding of an effector molecule D) Protein-protein interaction
1
How many promoters are in an operon?
A,B,C
How might heterochromatin silence the expression of genes? (Check all that apply.) A) Limiting the access of activators to the DNA B) Limiting the access of general transcription factors to the DNA C) Limiting the access of coactivators to the DNA D) Limiting the access of repressors to the DNA
Transcription would be difficult to activate in the absence of glucose
If CAP could not bind to its CAP site, then what would be the result? Assume lactose is present in each scenario.
Transcripts being produced would continue but there would be no new initiation.
If a DNA tempate is being transcribed in vitro what would be the effect on RNA production if an inhibitor of TFIID was added?
glucose
If a bacteria is placed in an environment that contains both glucose and lactose, the regulation of the lac operon will allow which nutrient to be processed first?
true
If a portion of a transcription factor's domain is structurally similar in a variety of organisms, it is called a motif.
The amount of DNA wrapped around a nucleosome
In ChIP-Seq, the DNA fragments to be sequenced are around 150 bp in length. What does this size of DNA represent?
1
In Jacob, Monod, and Pardee's experiment, how many functional copies of lac I were there in the merozygote?
Expression of the lac operon is constitutive whether lacI is functional or not
In Jacob, Monod, and Pardee's experiment, what would have been the conclusion if all four tubes produced a yellow color when b-ONPG was added?
2
In a particular E. coli strain, a mutation in the thiMD operon results in improper formation of the stem loop secondary structure making it impossible to bind TPP. There are two enzymes encoded by the thiMD operon. How many of the enzymes encoded in the thiMD operon are translated?
DNA that is wrapped around the histones is not being degraded.
In apoptosis, a process of programmed cell death, the cell undergoes controlled degradation of cellular components including nuclear DNA. Researchers have noted that if the DNA is isolated from an apoptotic cell, it appears as distinct bands of multiples of approximately 145 bases in length. Why does this occur?
No, directly determining the amount of protein produced would be best because many steps are involved in regulating protein levels.
In numerous studies that investigate gene expression, the mRNA levels of proteins are examined. If one is interested in the amount of protein being produced, is this the best approach to use?
Paternal; paternal
In the Igf-2 allele, which chromosome is imprinted? Which is expressed?
promoter; low
In the lac operon, the CAP site is located next to the __________. When both lactose and glucose are present, this leads to a rate of transcription that is __________.
false
In the lac operon, the operator site is recognized by an activator protein
an increase in ferritin mRNA translation and a decrease in transferrin receptor mRNA stability
In the presence of abundant iron in the cell, the iron binds IRP. The complex is then released from IREs leading to __________.
false
Negative transcriptional regulation is conducted by activator proteins
true
Nucleosome location may be changed by a process called ATP-dependent chromatin remodeling.
false
Operons that code for anabolic enzyme systems are typically regulated by inducers.
False
Operons that code for catabolic enzyme systems are typically regulated by repressors.
Creating a piece of DNA where the gene for the protein of interest is under control of a glucocorticoid response element.
Researchers frequently wish to produce proteins in cells in a regulated fashion so that they effects of the protein can be studied undercontditions twhen and when it is not present. Which of the strategies outlined below would be best sutied for these types of studies?
A,B
Select all structural motifs that promote protein dimerization. A) Leucine zipper B) Helix-loop-helix C) Helix-turn-helix D) Zinc finger
B,C
Select the events that are part of the mechanism for epigenetic regulation of the Igf2 gene. (Choose all that apply.) A) Methylation of the H19 locus B) Methylation of the ICR and DMR domains C) Binding of CTCFs to methylated sequences D) Methylation of CTCFs
true
Steroid hormones are an example of an effectorwhich regulates regulatory transcription factor activity.
True
The form of regulation that involves a physical change in the shape of an enzyme is called allosteric regulation.
true
The term enzyme adaptationis used to describe an enzyme that appears in a living cell following exposure to a specific substrate
True
The trimethylation of lysine 27 in histone H3(H3k27) causes the repression of the FLC gene
mRna
Translational regulatory proteins recognize specific areas of what molecule?
Both the Tsix and Xist are genes are in the Xic region
What gene(s) is/are encoded in the Xic?
TFIID
What general transcription factor is most often affected by regulatory transcription factors?
Xist and Tsix
What genes appear to be controlled by the Xic?
trpL
What is the gene responsible for attenuation in the trp operon?
Methylation
What is the molecular mechanism for imprinting a gene?
Transcription factors influencing one gene's expression may abnormally influence a neighboring gene's expression.
What might happen if the insulator between two genes is missing?
1-2 and 3-4
What stem-loop conformations favor attenuation?
Attenuation would not occur if tryptophan was high
What would be the result if the U-rich sequence after the 3/4 stem loop in the trp operon was replaced by a UG-rich sequence?
Expression of the regulated genes would become constitutive.
What would be the result of a mutation in Hsp90that prevented its binding to the glucocorticoid receptor?
True
When a glucocorticoid hormonebinds to the glucocorticoid receptor, HSP90 is released.
Core promoter
Which DNA sequence important for gene expression is usually contained within the NFR?
5' GAAC 3'3' CTTG 5'
Which DNA sequence would also work in place of the following bi-directional enhancer? 5' GTTC 3'3' CAAG 5'
lac/trp operon
Which of the following encode polycistronic mRNA? (Check all that apply.) A) Lac operon B) Operator site C) Trp operon D) CAP site
More than 80% of the human genome sequence is linked to a biological function.
Which of the following is a major finding from the ENCODE project?
GRE
Which of the following is a region in DNA that binds to a steroid receptor?
Phosphorylation of an enzyme
Which of the following is an example of post translational regulation in prokaryotes?
Between two genes
Which of the following is the most likely location of an insulator sequence?
Because histones can be moved around or ejected from the chromatin,DNA that is only sometimes wrapped around a histone might not be sequenced
Which of the following might complicate the interpretation of ChIP-Seq data?
Regulatory transcription factors
Which of the following recognizes response elements, control elements, and regulatory elements?
CREB protein dimer
Which one of the following directly interacts with the DNA as a transcriptional regulator?
No - it would be difficult to distinguish between the strains using this assay.
You are studying riboswitches in different bacterial strains and you mix up two of your samples! One sample is from E. coli and the other is from B. subtilis. You have an assay in the lab that allows you measure the levels of the enzymes encoded by the thi/thiMD operon (assume the enzymes from the two organisms are similar). Would this assay allow you to distinguish between the two strains?
False
in the lac operon, the operator is an example of a train-efffect genetic regulation.