Concept: Structural Regulation5m
Concept: Transcriptional Regulation6m
Concept: RNA Regulation5m
Concept: Translational and Post-Translational Regulation9m
Which of the following scenarios will result in gene activation?
A. Expression of a repressor increases.
B. A ligand promotes binding of a repressor to DNA.
C. An activator is degraded.
D. A ligand promotes binding of an activator to DNA.
Which of the following is NOT an end-product of a gene?
Methylation of DNA involves the addition of a methyl group to nucleotide bases. Which of the following does not apply?
A. Methylation of cytosine forms methyl-cytosine.
B. Methylation affects the three-dimensional structure of DNA.
C. Methylation has no effect on the structure of DNA.
D. Methylation affects gene expression.
Which of the following is NOT true about gene expression in Eukaryotes?
A. Gene expression can be regulated in the nucleus epigenetically.
B. Gene expression can be regulated transcriptionally by RNA editing.
C. Gene expression can be regulated in the cytoplasm by translation.
D. Gene expression can be regulated in the nucleus by post-translational modifications.
E. None of the above (all of the above statements are TRUE)
Identify whether each of the following is a DNA sequence (D) or a protein (P).
C. TATA box
Which of the following statements regarding RNA splicing is false?
A. Splicing is performed by the spliceosome.
B. Alternative splicing enables one gene to code for more than one protein.
C. Splicing takes place in the nucleus.
D. Splicing produces mature mRNA by removing exons and joining introns together.
E. Splicing is catalzed ribozymes in the spliceosome.
Protein degradation is one strategy to control gene expression and is considered ______.
A. transcription control
B. post-transcriptional control
C. translational control
D. post-translational control
In both eukaryotes and prokaryotes, gene expression can be regulated at the level of _____.
C. mRNA splicing
D. All of the above
E. transcription and translation only
The most important means of controlling gene expression in both prokaryotic and eukaryotic cells is at the level of _____.
B. chromatin modification
D. DNA packing
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments,she succeeded in decreasing methylation of histone tails. Which of the following results would she most likely see?
A. activation of histone tails for enzymatic function
B. decreased binding of transcription factors
C. increased chromatin condensation
D. inactivation of the selected genes
E. decreased chromatin condensation
How can gene expression be regulated post-transcriptionally?
A. Chromatin packing controls which genes are accessible to transcription factors and RNA polymerase.
B. RNA polymerase needs to be phosphorylated to allow for elongation to begin.
C. microRNAs can trigger degradation of mRNAs, preventing their translation.
D. Alternative splicing causes different protein products from the same unprocessed mRNA.
E. The 5' untranslated regions can interact with different translation initiation factors.
F. The rate of mRNA destruction varies based on protein interactions with the 5' and 3' untranslated regions.
Human cancer can be thought of as a genetic disease because most
A. cancer causing genes are inherited.
B. cancers arise from mutations that accumulate in the telomeres.
C. cancers arise from mutations in critical genes that regulate cell growth and division.
D. cancers arise from chromosome deficiencies or degradation which are inherited.
E. cancers are caused by viruses and it is wrong to consider it a disease arising from mutation.
True or False. Eukaryotes, but not prokaryotes, are able to control the expression of multiple genes at once.
B. False. Prokaryotes, but not eukaryotes, are able to control the expression of multiple genes at once.
C. False. Prokaryotes and eukaryotes are able to control the expression of multiple genes at once.
The effect of inhibiting the function of a histone deacetylase enzyme would likely lead to:
A. a more compact and more transcriptionally active chromatin
B. a less compact and less transcriptionally active chromatin
C. a more compact and less transcriptionally active chromatin
D. a less compact and more transcriptionally active chromatin
Cancer is considered a progressive multi-step disease, why is this?
A. Tumor development arises from the accumulation of 4-6 different mutations in cells over the course of many years.
B. Tumors development spreads to other tissue with time.
C. Tumor development requires mutations in the affected cells as well as defects in the immune system.
D. Tumor development happens in a step-wise fashion as telomeres shorten with each cell division.
E. Tumor development gets worse with time.
Which of the following statements about viruses is true?
A. Viruses contain multiple genes, and each of these genes is an oncogene.
B. Viruses are the root cause of most - if not all - cancers.
C. None of the other answer options is correct.
D. Human cancers have not been associated with viruses.
E. Viruses are a type of prokaryotic cell.
Monozygotic twins have identical DNA sequences, yet twins can differ in some physical orbehavioral traits.
What evidence suggests that epigenetic effects may cause these penotypic differences in monozygotic twins?
A. Younger twins have more similar DNA methylation and histone acetylation patterns than older twins.
B. Older twins increase DNA methylation, whereas younger twins increase histone acetylation.
C. Younger twins increase DNA methylation, whereas older twins increase histone acetylation.
D. Older twins have more similar DNA methylation and histoe acetylation patterns than younger twins.
Operons ae unique to bacteria, which are single-celled organisms. Why are they not practical foreukaryotic cells found in multicellular organisms like humans?
What is teh effect of a ras mutation that hyperactivates its GTPase activity?
A. promote cancer development
B. prevent cancer development
What will happen if a p53 mutation occurs that prevents p53 phosphorylation?
A. promote cancer development
B. prevent cancer development
All of the following is true about eukaryotic transcription except:
A. RNA polymerase is a processive enzyme.
B. The initial transcript must be processed before it leaves the nucleus.
C. Three different types of DNA polymerase to recognize the promoter.
D. A sigma factor allows RNA polymerase to recognize the promoter.
E. RNA made is complementary to DNA according to Chargaff's rules.
What is miRNA, RNA interference and SiRNA in gene?
Why does DNA methylation occurs and on which nucleotide?
What are the stages in which a gene could be regulated?
What is meant by the term gene expression?
What is meant by the term regulation?
What is the relationship between epigenetic regulation and gene expression?
What five types of RNA molecules participate in the process of gene expression? What are the functions of each type of RNA? Which types of RNA perform their function(s) in (a) the nucleus and (b) the cytoplasm?
Which of the following single-stranded DNA sequences is most likely to form a stem-loop structure?
What would be the phenotype (growth characteristic) of a cell that lacks the trp genes (genes required for thesynthesis of tryptophan)?
What would be the phenotype of a cell missing the lac genes (genes whose products catabolize the carbohydrate lactose)?
In eukaryotes, general transcription factors:
a. inhibit RNA polymerase binding to the promoter and begin transcribing.
b. bind to other proteins or to a sequence element within the promoter called the TATA box.
c. bind to sequences just after the start site of transcription.
d. usually lead to a high level of transcription even without additional specific transcription factors.
e. are required for the expression of specific protein-encoding genes.
Why do histones bind tightly to DNA?
a. Both histones and DNA are strongly hydrophobic
b. Both histones and DNA are negatively charged
c. Histones are neutrally charged
d. Histones are negatively charged, and DNA is positively charged
e. Histones are positively charged, and DNA is negatively charged
Processing of eukaryotic mRNA occurs in the cytoplasm prior to translation.
Splicing joins together
a. two introns.
b. two exons.
c. two polypeptides.
d. a DNA and an RNA molecule.
e. an RNA molecule and a polypeptide.
Which of the following statements about eukaryotic mRNA is TRUE?
a. a cap is added to their 5' end
b. a poly-A tail is added to their 3' end
c. each usually specifies only a single protein
d. A and B
e. A, B, and C
Which of the following is mechanism for DNA packaging?
a. alternative RNA splicing
b. transcription factors
d. histone acetylation
e. bending proteins
In eukaryotic cells gene expression may be controlled by not allowing mRNA to leave the nucleus.
An antisense RNA is complementary to a mRNA and could:
a. Prevent transcription of the mRNA
b. Increase translation of the mRNA
c. Increase transcription of the mRNA
d. Prevent translation of the mRNA
How can a single gene encode for more than one protein?
a. By mutating their genes
b. By removing some exons during splicing of mRNA
c. By transcribing multiple copies of mRNA
d. By using different codons
In humans, typically only infants produce the enzyme lactase to break down lactose. Some adults have changes in _____ that allow transcription factors to bind and turn on expression of the lactase gene into adulthood.
b. RNA polymerase
Proteins that initiate transcription in eukaryotes by recognizing sequences within the promoter region of a gene and attracting RNA polymerase are:
c. Transcription factors
d. TATA boxes
e. Poly A Tails
A nucleosome consists of:
a. A stretch of DNA and histones
b. A stretch of DNA
c. An RNA molecule
d. A ribosome and RNA
A chemical modification that methylates DNA bases causes:
a. Enhancement of transcription
b. Gene amplification
c. Activation of RNA polymerase
d. Inactivation and silencing of DNA
e. None of the above are correct