Chapter 17 Flashcards
Which of the following statements about regulation of the eukaryotic gene expression is INCORRECT?
a. The presence of a nuclear membrane separating transcription and translation in eukaryotes led to the evolution of additional mechanisms of gene regulation.
b. In eukaryotes, most structural genes are found within operons.
c. Eukaryotic mRNAs are generally more stable than prokaryotic mRNAs.
d. The rate of degradation of mRNAs is important in regulation in eukaryotes.
e. Post-translational regulation of histones is unique to the eukaryotes.
b. In eukaryotes, most structural genes are found within operons.
Which of the following statements about histone and gene expression is correct?
a. In a general sense, highly condensed DNA bound with histone proteins represses gene expression.
b. Acetylation involves the addition of acetyl groups to histone proteins, and it usually results in repression of transcription.
c. Addition of methyl groups to the tails of histone proteins always results in activation of transcription.
d. Histone code is referring to the modification that takes place on the globular domain of the octomeric histone core.
e. All statements above are correct.
a. In a general sense, highly condensed DNA bound with histone proteins represses gene expression.
Which of the following molecules is capable of targeting chromatin remodeling complexes to specific DNA sequences to modify chromatin structure and activate gene expression?
a. Transcriptional repressor
b. Enhancer
c. DNAse I
d. Transcriptional activators
e. Histone deacetylase
d. Transcriptional activators
Proteins that affect the structure of DNA bound to histones without altering histone chemical structure are called
a. RISCs.
b. chromatin-remodeling complexes.
c. splicing complexes.
d. MRE activator proteins.
e. Dicers.
b. chromatin-remodeling complexes.
When regions around genes become sensitive to the enzyme DNase I, this is an indication that those regions are
a. becoming transcriptionally active.
b. becoming more condensed.
c. binding to the single-strand binding proteins.
d. destabilizing and transcriptionally inactive.
e. becoming highly methylated by a methylase.
a. becoming transcriptionally active.
What is the consequence of methylation of DNA sequence called CpG islands?
a. Active transcription
b. Transcription repression
c. Recruitment of chromosome remodeling complex
d. Transcriptional stalling
e. Insulator sequence formation
b. Transcription repression
Which of the following events is known to make DNA to become more sensitive to digestion by DNase I?
a. DNA methylation
b. Deacetylation of histone
c. Acetylation of histone
d. Formation of heterochromatin
e. All of the above
c. Acetylation of histone
Which of the following is NOT addressed by performing chromatin immunoprecipitation (ChIP) technique?
a. The types of modification done on the DNA-binding proteins
b. The location of modified histones that activate or repress transcription
c. The position of transcription factors and associated regulators on the chromosome
d. Identification of active promoters on genome-wide level
e. All of the above
e. All of the above
Choose the correct order of procedure in performing chromatin immunoprecipitation (ChIP).
- DNA sequencing and fragment identification
- Removal of crosslinking and separation of DNA and proteins
- Crosslinking proteins and chromosomes via UV
- Antibody incubation for immunoprecipitation
- Protein degradation via proteases
- Cell lysis and chromosome fragmentation
a. 1, 3, 2, 4, 5, 6
b. 2, 6, 5, 1, 3, 4
c. 4, 3, 2, 5, 1, 5
d. 3, 6, 4, 2, 5, 1
e. 5, 1, 3, 6, 4, 2
d. 3, 6, 4, 2, 5, 1
3. Crosslinking proteins and chromosomes via UV
6. Cell lysis and chromosome fragmentation
4. Antibody incubation for immunoprecipitation
2. Removal of crosslinking and separation of DNA and proteins
5. Protein degradation via proteases
1. DNA sequencing and fragment identification
- Which of the following statements about CpG islands is correct?
a. CpG islands are commonly found at the 3′ UTR regions.
b. The CpG island methylation is universal across both prokaryotes and eukaryotes.
c. Methylated CpG islands is associated with long term gene repression.
d. Transcriptionally active DNA has higher frequency of methylated CpG.
e. There is an association exists between DNA methylation at the CpG island and acetylation of histone via recruitment of acetylases.
c. Methylated CpG islands is associated with long term gene repression.
In Arabidopsis, FLD (a deacetylase enzyme) stimulates flowering. Which of the following is TRUE?
a. FLD deacetylates histones that bind to regions of FLC gene and stimulates its transcription.
b. FLD deaceylates histones surrounding FLD gene, causing suppression of FLD transcription.
c. FLD deacetylates histones that bind to FLC gene, causing repression of FLC transcription.
d. FLD causes repression of FLC translation.
c. FLD deacetylates histones that bind to FLC gene, causing repression of FLC transcription.
Which of the following facts about eukaryotic gene regulation is TRUE?
a. Transcriptional activator proteins bind to the DNA in non specific manner.
b. Eukaryotic enhancers are a part of basal transcription apparatus.
c. The eukaryotic regulatory promoters are highly conserved with the same consensus sequences throughout the genome.
d. Mediators are protein complexes involved in regulating transcription rates.
e. The transcriptional repressors always bind to the insulator elements.
d. Mediators are protein complexes involved in regulating transcription rates.
Which of the following terms is least relevant to the assembly of basal transcription apparatus for transcription?
a. Core promoter
b. General transcription factors
c. TATA box
d. RNA polymerase.
e. Enhancer
e. Enhancer
A boundary element is also known as a(n)
a. insulator.
b. repressor.
c. enhancer.
d. coactivator.
e. mediator.
a. insulator.
A eukaryotic DNA sequence that affects transcription at distant promoters is called a(n)
a. insulator.
b. silencer.
c. mediator.
d. enhancer.
e. repressor.
d. enhancer.
