Exam 4 BIOL

Which of the following is not a post-transcriptional stage of gene regulation? a.) transport of mRNA from nucleus to cytoplasm b.) protein processing and degradation c.) RNA processing d.) degradation of mRNA e.) chromatin modification

chromatin modification

Which of the following regulatory elements is not composed of DNA sequences? a.) Enhancors b.) Activators c.) Silencers d.) Promoter-proximal elements

Activators

_____ bind(s) to DNA enhancer regions. a.) RNA polymerase b.) Promoters c.) Introns d.) Activators e.) Exons

Activators

In the attached image of the trp operon, trpR is the regulatory gene, and trpA-trpE are the trp genes encoding the three enzymes (AB, C, and DE). Using gene editing techniques, we move the trp operon upstream of the promoter. What happens when tryptophan is present? A. All of the genes are transcribed B. None of the genes are transcribed C. The genes are transcribed, but slowly

All of the genes are transcribed

Which of the following statements correctly describes the role of histone acetylation and DNA methylation in gene regulation? a.) DNA methylation reduces transcription, and histone acetylation promotes transcription. b.) DNA methylation promotes transcription, and histone acetylation reduces transcription. c.) DNA methylation and histone acetylation both reduce transcription. d.) DNA methylation and histone acetylation both promote transcription.

DNA methylation reduces transcription, and histone acetylation promotes transcription.

Which of the following regulatory DNA sequences might be located thousands of nucleotides away from the transcription start site of a gene? a.) TATA box b.) Promoter-proximal elements c.) Enhancer d.) Promoter

Enhancer

True or false? One possible way to alter chromatin structure such that genes could be transcribed would be to make histone proteins more positively charged. a.) True b.) False

False

Which statement about DNA in one of your brain cells is true? A. Most of the DNA codes for protein. B. The majority of genes are likely to be transcribed. C. It is the same as the DNA in one of your liver cells. D. Many genes are grouped into operon-like clusters.

It is the same as the DNA in one of your liver cells.

Which of the following environments would most likely lead to low level transcription of the lactose operon? A. Lactose present, glucose scarce B. Lactose present, glucose present C. Lactose scarce, glucose scarce D. Lactose scarce, glucose present

Lactose present, glucose present

Which of the following terms describes the DNA-protein complexes that look like beads on a string? a.) Histones b.) Chromatin c.) Nucleosome d.) 30-nanometer

Nucleosome

Which of the following is an example of post-transcriptional (and translational!) control of gene expression? A. Addition of methyl groups to DNA B. Binding of transcription factor to promotor C. Protein Processing D. Binding of activators to control elements

Protein Processing

Which of the following events in transcription initiation likely occurs last? a.) RNA polymerase binds to the promoter of the gene b.) Basal transcription factors form a basal transcription complex c.) TBP is recruited to the promoter d.) Regulatory transcription factors bind to enhancers

RNA polymerase binds to the promoter of the gene

Which of the following must occur in order for a repressible (or inducible) operon to be transcribed? A. RNA polymerase must bind to the promoter, and the repressor must be inactive B. A corepressor must be present C. RNA polymerase cannot be present, and the repressor must be inactive D. RNA polymerase and the active repressor must be present

RNA polymerase must bind to the promoter, and the repressor must be inactive

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the regulatory gene (lac I), along with its promoter, to a position some several thousand base pairs away from its normal position, which would you expect to occur? a.) The repressor will no longer bind to the operator. b.) The repressor will no longer bind to the inducer. c.) The repressor will no longer be made. d.) The lac operon will function normally.

The lac operon will function normally.

Suppose an experimenter becomes proficient with a technique that allows her to move DNA sequences within a prokaryotic genome. If she moves the operator to the far end of the operon, past the transacetylase (lacA) gene, which of the following results would likely occur when the cell is exposed to lactose? a.) The repressor will no longer bind to the operator. b.) The three genes of the operon will be transcribed continuously. c.) The operon will never be transcribed. d.) The inducer will no longer bind to the repressor.

The three genes of the operon will be transcribed continuously.

If you were to observe gene expression in a cell, which of the following clues would indicate that the cell is prokaryotic? a.) There are mRNAs that are being translated at the same time as they are being transcribed. b.) Spliceosomes are carrying out RNA splicing. c.) A single gene has many RNA polymerases bound to it. d.) A single mRNA has many ribosomes bound to it.

There are mRNAs that are being translated at the same time as they are being transcribed.

Which of the following processes do steroid hormones carry out to produce their effects? a.) They activate key enzymes in metabolic pathways. b.) They bind to receptors inside the cell and promote transcription of specific genes. c.) They activate translation of certain mRNAs. d.) They promote the breakdown of specific mRNAs.

They bind to receptors inside the cell and promote transcription of specific genes.

What would be the result of a mutation that deactivates the regulatory gene of a repressible operon in an Escherichia coli cell? a.) continuous transcription of the enzyme-coding gene controlled by that regulator b.) irreversible binding of the repressor to the operator c.) complete inhibition of transcription of the enzyme-coding gene controlled by that regulator d.) inactivation of RNA polymerase by alteration of its active site

continuous transcription of the enzyme-coding gene controlled by that regulator

What would occur if the repressor of an inducible operon were mutated so it could NOT bind the operator? a.) irreversible binding of the repressor to the promoter b.) continuous transcription of the operon's genes c.) reduced transcription of the operon's genes d.) buildup of a substrate for the pathway controlled by the operon

continuous transcription of the operon's genes

What would occur if the repressor of an inducible operon were mutated so it could not bind the operator? A. irreversible binding of the repressor to the promoter B. reduced transcription of the operon's genes C. buildup of a substrate for the pathway controlled by the operon D. continuous transcription of the operon's genes

continuous transcription of the operon's genes

A lack of which of the following molecules would result in the cell's inability to "turn off" genes? a.) operon b.) corepressor c.) inducer d.) promoter

corepressor

In positive control of several sugar-metabolism-related operons, the cAMP receptor protein (CRP) binds to DNA to stimulate transcription. Which of the following events activates CRP? a.) ncrease in glucose and decrease in cAMP b.) decrease in glucose and increase in cAMP c.) increase in glucose and increase in cAMP d.) decrease in glucose and increase in repressor

decrease in glucose and increase in cAMP

True or false? Regulatory and basal transcription factors regulate transcription by binding to the promoter. a.) true b.) false

false

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then a.) the amino acid inactivates the repressor. b.) the repressor is active in the absence of the amino acid. c.) the amino acid acts as a corepressor. d.) the amino acid turns on transcription of the operon.

the amino acid acts as a corepressor.

Which of the following is an example of post-transcriptional control of gene expression? a.) the binding of RNA polymerase to transcription factors b.) the removal of introns and alternative splicing of exon c.) the addition of methyl groups to cytosine bases of DNA d.) the binding of transcription factors to a promoter

the removal of introns and alternative splicing of exon

Which of the following is an example of post-transcriptional control of gene expression? A. the addition of methyl groups to cytosine bases of DNA B. the binding of transcription factors to a promoter C. the removal of introns and alternative splicing of exons D. the binding of RNA polymerase to transcription factors

the removal of introns and alternative splicing of exons

The functioning of enhancers is an example of __________. a.) the stimulation of translation by initiation factors b.) transcriptional control of gene expression c.) a eukaryotic equivalent of prokaryotic promoter function d.) post-translational control that activates certain proteins

transcriptional control of gene expression

The functioning of enhancers is an example of A. a eukaryotic equivalent of prokaryotic promoter function. B. transcriptional control of gene expression. C. the stimulation of translation by initiation factors. D. post-translational control that activates certain proteins.

transcriptional control of gene expression.