46 Questions
Which of the following is a component of the lac operon in prokaryotes?
lac Repressor
What is the function of cAMP in the regulation of transcription in prokaryotes?
It stimulates transcription of the lac operon
Which of the following is involved in the epigenetic regulation of transcription in eukaryotes?
Deacetylation of Histones
Which of the following is a cis-acting regulatory element that is located closest to the transcription start site of a gene?
Proximal promoter elements
Which of the following is a cis-acting regulatory element that can activate transcription independent of distance from the core promoter?
Enhancer
Which of the following is a trans-acting factor involved in the regulation of transcription?
Activator
Which of the following is a functional domain of an activator protein?
Transactivation Domain (TAD)
Which type of regulation is described in the lac operon model?
Negative regulation
What is the function of the lac repressor protein?
To bind to the operator and repress transcription
What is the role of cAMP in the positive regulation of the lac operon?
To bind to a protein called CAP and facilitate binding of RNA polymerase to the promoter
Which statement is true about the regulation of the lac operon in the presence of both lactose and glucose?
Transcription of the lac operon is repressed
Which of the following is true about zinc fingers?
They are stabilized by a zinc ion coordinately bound to 2 Cys and 2 His residues
What happens when a steroid hormone binds to the ligand binding domain of its receptor?
It causes a conformational change in tertiary protein structure
What is the role of DNA methylation in gene transcription?
It silences transcription of a gene by epigenetic mechanisms
What is the effect of histone acetylation on chromatin structure?
It relaxes (opens) chromatin structure and makes it more accessible to transcription factors
Which enzyme is responsible for deacetylating lysine residues in histones?
Histone deacetyltransferases (HDACs)
What is the function of coactivator complexes in gene regulation?
To increase accessibility of regulatory elements
What is the role of DNase I hypersensitive sites in gene regulation?
To indicate regions of transcriptionally active euchromatin
Which of the following is NOT a mechanism of epigenetic regulation of chromatin structure?
Protein phosphorylation
Which domain of a repressor protein recruits and/or activates corepressors and other mediator proteins to modify chromatin structure and repress assembly of a pre-initiation complex on the core promoter of a target gene?
Transrepression Domain (TRD)
Which type of repressor protein binds directly to an activator and prevents it from activating transcription?
Repressor protein that causes a conformational change in the activator
What is the function of the dimerization domain in specific transcription factors?
Forms a dimer for sequence-specific binding to a cis-acting element in DNA
Which family of specific transcription factors is enriched in basic amino acids (Lys and Arg) and binds directly to a consensus sequence in a cis-acting element such as an enhancer?
Basic-Leucine Zipper (bZIP) Family
What is the function of a-Amanitin?
It inhibits transcription in eukaryotes
Which of the following is NOT a mechanism of epigenetic regulation of chromatin structure?
Deacetylation of histones by HDACs
Which of the following is a trans-acting factor involved in the regulation of transcription?
Specific transcription factor
Which of the following is a cis-acting regulatory element that can activate transcription independent of distance from the core promoter?
Enhancers
Which of the following is a trans-acting factor involved in the regulation of transcription?
Activators
Which of the following is a functional domain of an activator protein?
Transactivation Domain (TAD)
Which of the following is a consensus binding sequence in a cis-acting element for the specific transcription factor Myc?
GGGCGG
Which of the following is a mechanism of chromatin remodeling?
Removal of individual nucleosomes
Which of the following is a function of lncRNAs in gene regulation?
Titrate transcription factors away from a gene
Which antibiotic prevents the formation of the first phosphodiester bond by RNA Polymerase?
Rifampicin
Which of the following is a function of HDACs in gene regulation?
Deacetylate histones
Which of the following is a key component of the lac operon in prokaryotes?
Promoter
Which of the following is NOT a mechanism by which a repressor can inhibit transcription of a target gene?
Binding directly to an activator protein
Which of the following families of specific transcription factors is enriched in basic amino acids (Lys and Arg) and binds directly to a consensus sequence in a cis-acting element such as an enhancer?
bZIP
What is the function of DNase I hypersensitive sites in gene regulation?
To enhance the binding of transcription factors to DNA
Which of the following is a covalent modification of histones that can regulate transcription of specific genes?
Acetylation
What is the role of DNA methylation in gene transcription?
Inhibits binding of an activator to cis-acting elements
Which of the following is a cis-acting element that is located closest to the transcription start site of a gene?
Promoter
What is the function of the dimerization domain in specific transcription factors?
Forms a dimer for sequence-specific binding to DNA
Which domain of a repressor protein is responsible for recruiting and/or activating corepressors and other mediator proteins to modify chromatin structure and repress assembly of a pre-initiation complex on the core promoter of a target gene?
Transrepression Domain (TRD)
Which type of repressor protein binds directly to an activator and prevents it from activating transcription?
Direct Inhibition of Activator Protein repressor
Which family of specific transcription factors is enriched in basic amino acids (Lys and Arg) and binds directly to a consensus sequence in a cis-acting element such as an enhancer?
Basic-Leucine Zipper (bZIP) Family
What is the function of the dimerization domain in specific transcription factors?
Allows specific transcription factors to function as homodimers or heterodimers
Test your knowledge on repressors and their role in gene regulation with this quiz. Learn about the different functional domains of repressors and how they function to repress gene expression.
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