MasteringBiology: Regulation Of Eukaryotic Transcription

Which statements about the modification of chromatin structure in eukaryotes are true? a. Acetylation of histone tails is a reversible process. b. DNA is not transcribed when chromatin is packaged tightly in a condensed form. c. Deacetylation of histone tails in chromatin loosens the association between nucleosomes and DNA. d. Methylation of histone tails in chromatin can promote condensation of the chromatin. e. Acetylation of histone tails in chromatin allows access to DNA for transcription. f. Some forms of chromatin modification can be passed on to future generations of cells.

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

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

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

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

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

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

Which of the following best describes the mechanism by which steroid hormones control gene expression? a. Steroid hormones transport mRNA from the nucleus into the cytoplasm, where it is translated into protein. b. Chaperone proteins transport steroid hormones into the cell and guide them to their target genes. c. Steroid hormones enter a cell, bind directly to hormone response elements (HREs), and enhance transcription. d. Steroid hormones that enter the cell activate receptors. These hormone-receptor complexes then bind HREs and influence gene expression.

Which of the following best describes the role of chaperone proteins in the regulation of gene expression by steroid hormones? a. Chaperone proteins maintain functionality of the receptor. b. Chaperone proteins activate receptor proteins. c. Chaperone proteins directly enhance transcription. d. Chaperone proteins enter the cell and bind receptor molecules.

The reason some cells respond to the presence of a steroid hormone while others do not is that _______. a. the receptors necessary for regulation differ among cells of various types b. the specific HRE is present only in certain cells c. chaperone proteins block the hormone response elements (HREs) in some cells d. only certain cells contain the gene that is targeted by a given steroid hormone

The most common type of regulation of gene expression occurs at the level of transcription. Select other types of regulation for gene expression in eukaryotic cells. a. RNA transport b. protein stability (half-life) c. protein transport d. RNA stability e. post-translational modifications of proteins f. transcript stability g. initiation of translation h. splicing

Are there any types of regulation unique to eukaryotic cells versus prokaryotic cells? a. Yes, initiation of translation and splicing. b. Yes, initiation of translation and control of transport of RNA or proteins to specific organelles. c. Yes, splicing and control of transport of RNA or proteins to specific organelles. d. No.

Which of the following protein domains would be most likely to recognize and bind to acetylated lysine residues on nucleosomes? a. bromodomains b. chromodomains c. zinc fingers d. homeodomains

Which of the following mechanisms illustrates a form of transcriptional repression that is unique to eukaryotes? a. repressors binding to a site near an activator binding site where they interact with and inhibit the activator b. repressors blocking RNA polymerase by binding an operator site within the promoter c. repressors recruiting enzymes to modify groups on histones to compact chromatin d. repressors recruiting enzymes to modify groups on histones to loosen chromatin