Chapter 15 Genetics Study Guide Questions

Which DNA sequence would also work in place ofthe following bi-directional enhancer? 5' GTTC 3'3' CAAG 5' A) 5' GAAC 3'3' CTTG 5' B) 5' CTTG 3'3' GAAC 5' C) 5' CAAG 3'3' GTTC 5' D) 5' CTTC 3'3' GAAG 5'

A) 5' GAAC 3'3' CTTG 5'

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? A) No, directly determining the amount of protein produced would be best because many steps are involved in regulating protein levels. B) Yes, this is the best approach because all mRNA is eventually translated into protein. C) No, examining the transport of mRNA from the nucleus would provide more reliable data since mRNA must be transported to the cytoplasm for translation. D) No, examining mRNA processing would be more reliable since that is the limiting step for protein production.

A) No, directly determining the amount of protein produced would be best because many steps are involved in regulating protein levels.

In the presence of abundant iron in the cell, the iron binds IRP. The complex is then released from IREs leading to __________. A) an increase in ferritin mRNA translation and a decrease in transferrin receptor mRNA stability B) an increase in transferrin receptor mRNA stability and a decrease in ferritin mRNA translation C) an increase in transferrin receptor mRNA stability and ferritin mRNA translation D) a decrease in transferrin receptor mRNA stability and ferritin mRNA translation

A) an increase in ferritin mRNA translation and a decrease in transferrin receptor mRNA stability

Which of the following might complicate the interpretation of ChIP-Seq data? A)Because histones can be moved around or ejected from the chromatin,DNA that is only sometimes wrapped around a histone might not be sequenced. B)DNA wrapped around nucleosomes can never be sequenced. C)The regions of DNA wrapped around a histone is too long to be sequenced with current technologies. D)The DNA between nucleosomes are too compacted to be sequenced.

A)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 DNA sequence important for gene expression is usually contained within the NFR? A)Core promoter B)CREB binding site C)Histone binding site D)Transcription termination sequence E)Hormone response element

A)Core promoter

Which of the following is a region in DNA that binds to a steroid receptor? A)GRE B)IRE C)CRE D)CREB

A)GRE

Which of the following is a major finding from the ENCODE project? A)More than 80% of the human genome sequence is linked to a biological function. B)In humans, one gene encodes exactly one protein. C)Genes were identified for all known diseases. D)There are more than 10 million regulatory sites in human DNA.

A)More than 80% of the human genome sequence is linked to a biological function.

Researchers frequently wish to produce proteins in cells in a regulated fashion so that the effects of the protein can be studied under conditions then and when it is not present. Which of the strategies outlined below would be best suited for these types of studies? A) Creating a piece of DNA where the gene for their protein of interest is under the control of a housekeeping gene promoter. B) Creating a piece of DNA where the gene for the protein of interest is under control of a glucocorticoid response element. C) Creating a piece of DNA where the gene for the protein of interest lacks any regulatory regions and only has a core promoter. D) Creating a piece of DNA where the gene for the protein of interest is not changed from how it is in the genome.

B) Creating a piece of DNA where the gene for the protein of interest is under control of a glucocorticoid response element.

What activates CREB? A) Binding of cAMP B) Phosphorylation C) Dimerization D) Lowering of cAMP concentration E) Binding to GRE

B) Phosphorylation

Which of the following recognizes response elements, control elements, and regulatory elements? A) General transcription factors B) Regulatory transcription factors C) Mediator D) Transactivation domains

B) Regulatory transcription factors

CpG islands are associated with which of the following? A)Nucleosome location B)DNA methylation C)Steroid hormone activity D)cAMP pathway

B)DNA methylation

What general transcription factor is most often affected by regulatory transcription factors? A)TFIIB B)TFIID C)TFIIE D)TFIIF

B)TFIID

What might happen if the insulator between two genes is missing? A)Without the insulator, neither gene can be transcribed. B)Transcription factors influencing one gene's expression may abnormally influence a neighboring gene's expression. C)Transcription factors will not be able to influence the expression of either gene. D)Without insulation, both genes will be expressed at maximal levels. E)Transcription factors will not be able to bind to the insulator.

B)Transcription factors influencing one gene's expression may abnormally influence a neighboring gene's expression.

If a DNA tempate is being transcribed in vitro what would be the effect on RNA production if an inhibitor of TFIID was added? A)Transcription would stop immediately. B)Transcripts being produced would continue but there would be no new initiation. C)Transcription would stop immediately but there would be one more round of initiation. D)Transcription rates of templates already being transcribed would increase but there would be no new initiation.

B)Transcripts being produced would continue but there would be no new initiation.

Histone acetyltransferases are directly involved in which of the following? A)Removal of histones from chromatin B)Movement of nucleosomes C)Chemical modification of histones D)Termination of gene expression E)Insertion of variant histone proteins

C)Chemical modification of histones

Genomic imprinting is a result of ___________. A)nucleosome location B)histone activation C)DNA methylation D)serine to leucine changes in the genetic code

C)DNA methylation

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? A)There is a specific DNase that digests DNA every 145 base pairs. B)DNA sequences that appear every 145 base pairs allows for easier DNA breakage. C)DNA that is wrapped around the histones is not being degraded. D)DNA is coated with transcription factors every 145 base pairs.

C)DNA that is wrapped around the histones is not being degraded.

What would be the result of a mutation in Hsp90that prevented its binding to the glucocorticoid receptor? A)Glucocorticoid receptor could not form a dimer. B)The nuclear localization signal would no longer function. C)Expression of the regulated genes would become constitutive. D)The hormone would not be able to bind to the glucocorticoid receptor.

C)Expression of the regulated genes would become constitutive.

A mutation in the iron response protein (IRP) that made it incapable of binding iron would result in __________. A)no expression of either ferritin and transferrin receptor B)constitutive transferrin receptor and ferritin expression C)constitutive transferrin receptor and no ability to stimulate ferritin expression D)an increase in transferrin receptor and ferritin expression

C)constitutive transferrin receptor and no ability to stimulate ferritin expression

A particular cell contains all of the standard histones but lacks several histone variants. Which of the following MAY be true of this cell? A) The cell will be completely unable to remodel its chromatin. B) The cell will have an enhanced ability to chemically modify its histones. C) The cell will be unable to express any of its genes at all. D) The cell will express different sets of genes than other cells in the same organism. E) The cell will not be able to divide.

D) The cell will express different sets of genes than other cells in the same organism.

Which of the following is the most likely location of an insulator sequence? A)At the end of a gene B)In the middle of a gene C)At the beginning of a gene D)Between two genes E)Within an intron

D)Between two genes

Which one of the following directly interacts with the DNA as a transcriptional regulator? A)cAMP B)G protein C)Protein kinase A D)CREB protein dimer E)Glucocorticoid response element

D)CREB protein dimer

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? A)The expression of the gene would be abnormally high. B)The effect on gene expression is impossible to predict. C)The gene would encode a different protein instead. D)The expression of the gene would be abnormally low or absent. E)The promoter of the gene will be constantly available to transcription factors and RNA polymerase.

D)The expression of the gene would be abnormally low or absent.

A mutation in which of the following would result in little or no effect on the expression of a gene regulated by a CRE? A) G protein B) Adenylyl cyclase C) Protein kinase A D) CREB E) Glucocorticoid receptor

E) Glucocorticoid receptor

For which of the following histones has variant forms not yet been identified? A)H1 B)H2A C)H2B D)H3 E)H4

E)H4

A heterodimer occurs when two identical transcription factors interact on a sequence of DNA. ⊚true⊚false

False

A repressor protein would enhance the ability of TFIID to bind to the TATA box of the promoter. ⊚ true ⊚ false

False

A transactivation domain is an example of a motif found in transcription factors. ⊚ true ⊚ false

False

Activator proteins bind to silencer sequences and repressor proteins bind to enhancer sequences. ⊚true⊚false

False

DNA methylation usually activates gene expression. ⊚ true ⊚ false

False

DNA that contains actively transcribed genes would most likely contain chromatin in the closed configuration. ⊚true⊚false

False

Insulators exert their effects on gene expression through histone acetyltransferase, histone deacetylase, and RNA polymerase. ⊚true⊚false

False

Methylation of DNA bases is one way that regulatory transcription factors may influence gene expression. ⊚ true ⊚ false

False

Prior to hormone binding, receptors for steroid hormones are usually found in the nucleus of the cell. ⊚ true ⊚ false

False

In ChIP-Seq, the DNA fragments to be sequenced are around 150 bp in length. What does this size of DNA represent? A) The length of a promoter B) The amount of DNA wrapped around a nucleosome C) The average length of a gene D) The average distance between genes E) The amount of DNA between nucleosomes

The amount of DNA wrapped around a nucleosome

Housekeeping genes are unmethylated and active in most cells. ⊚true⊚false

True

If a portion of a transcription factor's domain is structurally similar in a variety of organisms, it is called a motif. ⊚true⊚false

True

Nucleosome location may be changed by a process called ATP-dependent chromatin remodeling. ⊚ true ⊚ false

True

Steroid hormones are an example of an effectorwhich regulates regulatory transcription factor activity. ⊚true⊚false

True

The activity of some transcription factors can be regulated by covalent modifications. ⊚ true ⊚ false

True

When a glucocorticoid hormonebinds to the glucocorticoid receptor, HSP90 is released. ⊚ true ⊚ false

True

Select all structural motifs that promote protein dimerization. A)Leucine zipper B)Helix-loop-helix C)Helix-turn-helix D)Zinc finger

[A,B] Leucine zipper helix loop helix

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

[A,C,D] covalent modification binding of an effector molecule protein-protein interaction