Questions from All Exams and Quizzes Flashcards
Which of the following are NOT characteristics of a DNA double helix?
a. nitrogenous bases on the inside of the helix
b. strands antiparallel
c. 25 bases per one turn of the helix
d. A-T base pairs contain two hydrogen bonds, C-G base pairs contain 3 hydrogen bonds
c. 25 bases per one turn of the helix
How do purines and pyrimidines differ?
a. pyrimidines have a double ring while purines have a single ring structure
b. purines are the components of RNA; pyrimidines are only found in DNA
c. purines have double ring while pyrimidines have a sing ring structure
d. pyrimidines are only found in RNA; purines are the components of DNA
c. Purines have the double ring while pyrimidines have a single ring structure
Which of the following statements about the major groove of double stranded DNA is true?
a. It is narrower than the minor groove.
b. It refers to the space between the sugar and the phosphate on the DNA backbone.
c. It allows proteins to ‘read’ the DNA sequence without disrupting the double helix.
d. All of the statements are correct.
e. None of the statements are correct
c. It allows proteins to ‘read’ the DNA sequence without disrupting the double helix
One function of DNA pol I during replication in prokaryotes is to:
a. join the ends of adjacent Okazaki fragments together
b. separate the double-stranded DNA into single-stranded regions
c. replicate the lagging strand of DNA in eukaryotic cells
d. relieve tension induced by supercoiling
e. remove the RNA primers that initiate replication
e. Remove the RNA primers that initiate replication
Which of the following is NOT a property of DNA polymerase III?
a. It is responsible for incorporating most of the nucleotides in the leading strand.
b. It contains a 3’ to 5’ proofreading activity.
c. It is responsible for incorporating most of the nucleotides in the lagging strand.
d. It does not require primers to extend the leading strand.
e. It has a very low error rate.
d. It does not require primers to extend the leading strand
If the sequence GTGAT mutates to become GTAAT, the G to A alteration is called a:
a. depurination
b. transversion
c. transition
d. tautomeric shift
c. Transition
Which of the following is NOT a step in the repair of a deaminated cytosine?
a. N-glycosylase to remove the damages base
b. primase to synthesize an RNA primer
c. apyrimidinic endonuclease to nick the backbone at the damaged base
d. DNA polymerase to add the correct base
e. DNA ligase to seal the nick in the backbone
b. Primase to synthesize an RNA primer
Site-directed mutagenesis:
a. can be used to produce a specific allele of a gene
b. can be used to modify the function of a gene
c. can be used to modify the binding site for a repressor in the 5’ untranslated region of a gene
d. can be used to restore a mutant gene back to wild-type sequence
e. all of the above
e. All of the above
Restriction enzymes usually only cut foreign viral DNA and ignore their own bacterial DNA. The
reason for this behavior is:
a. their bacterial DNA is methylated
b. transcriptional repression of the restriction enzyme’s structural gene
c. translational modification of the restriction enzyme
d. the heterochromatin state of the bacterial DNA
e. the foreign viral DNA is methylated
a. Their bacterial DNA is methylated
The enzyme used in PCR is:
a. DNA ligase
b. a thermostable DNA polymerase
c. reverse transcriptase
d. the restriction endonuclease PvuII
e. the single-stranded binding protein PCNA
b. A thermostable DNA polymerase
A tautomeric shift during replication can cause the following type of mutation: True / False 11. missense mutation True / False 12. repeat tract expansion True / False 13. silent mutation True / False 14. frameshift mutation True / False 15. neutral mutation
True 11. missense mutation False 12. repeat tract expansion True 13. silent mutation False 14. frameshift mutation True 15. neutral mutation
Which of the following statements about RNA and DNA are true and which are false?
True / False 16. RNA contains ribose rather than deoxyribose sugars
True / False 17. DNA secondary structure is less variable than RNA
True / False 18. RNA polymers incorporate uracil
True / False 19. RNA has a –OH group on the 2’ carbon that DNA lacks
True / False 20. RNA cannot serve as the genetic information storage medium
True 16. RNA contains ribose rather than deoxyribose sugars
True 17. DNA secondary structure is less variable than RNA
True 18. RNA polymers incorporate uracil
True 19. RNA has a –OH group on the 2’ carbon that DNA lacks
False 20. RNA cannot serve as the genetic information storage medium
The function of topoisomerases during replication is to:
True / False 21. join the ends of adjacent Okazaki fragments together
True / False 22. separate the DNA strands from each other
True / False 23. relieve tension induced by supercoiling
True / False 24. remove the RNA primers that initiate replication
True / False 25. generate the primer used to initiate synthesis
The function of topoisomerases during replication is to:
False 21. join the ends of adjacent Okazaki fragments together
False 22. separate the DNA strands from each other
True 23. relieve tension induced by supercoiling
False 24. remove the RNA primers that initiate replication
False 25. generate the primer used to initiate synthesis
Which repair mechanism acts on an apurinic site?
Base excision repair
Which repair mechanism acts on a thymine dimer?
Nucleotide excision repair OR Photolyase
Which repair mechanism acts on a T:C base pair in interphase?
Mismatch repair OR DNA Proofreading
Which repair mechanism acts on a double-stranded break?
Recombinational repair
Which repair mechanism acts on an A:G base pair during DNA synthesis?
DNA Proofreading
Which statement about DNA polymerase III is FALSE?
a. It is responsible for incorporating most of the nucleotides in the leading strand.
b. It contains a 3’ to 5’ proofreading activity.
c. It is responsible for incorporating most of the nucleotides in the lagging strand.
d. It does not require primers to extend the leading strand.
e. It has a very low error rate.
d. It does not require primers to extend the leading strand
One function of DNA pol I during replication in prokaryotes is to:
a. join the ends of adjacent Okazaki fragments together
b. separate the double-stranded DNA into single-stranded regions
c. replicate the lagging strand of DNA in eukaryotic cells
d. relieve tension induced by supercoiling
e. remove the RNA primers that initiate replication
e. Remove the RNA primers that initiate replication
The enzyme used in making cDNA is:
a. DNA ligase
b. a thermostable DNA polymerase
c. reverse transcriptase
d. polynucleotide kinase
e. the single-stranded binding protein PCNA
c. Reverse transcriptase
7-methyl-guanosine is added to mRNA molecules during a processing reaction in eukaryotes. The
unique processing event is a:
a. 3’-5’ triphosphate linkage at the 3’ end of the RNA
b. 2’-5’ triphosphate linkage at the 5’ end of the RNA
c. 3’-5’ triphosphate linkage at the 5’ end of the RNA
d. 3’-2’ triphosphate linkage at the 3’ end of the RNA
e. 5’-5’ triphosphate linkage at the 5’ end of the RNA
e. 5’-5’ triphosphate linkage at the 5’ end of the RNA
The reduced expression of the lac operon in the presence of glucose is an example of :
a. transcriptional activation
b. catabolite repression
c. operon silencing
d. regulatory dominance
e. anabolic repression
b. Catabolite repression
Attenuation at the trp operon in E. coli occurs when:
a. translation and transcription become uncoupled
b. high tryptophan levels inhibit the binding of a repressor protein
c. low tryptophan levels increase the rate of RNA polymerase progression
d. high tryptophan levels allow the formation of a terminator stem-loop in the trpL mRNA
e. the tryptophan membrane transporter increases the rate of tryptophan import
d. High tryptophan levels allow the formation of a terminator stem-loop in the trpL mRNA
Which is most commonly found in the P site of ribosomes?
a. a tRNA with the growing peptide chain attached
b. a tRNA with no amino acid attached
c. a tRNA with a single amino acid attached
d. ribosome releasing factor
e. termination factor
a. A tRNA with the growing peptide chain attached
Which statement about the Shine-Delgarno sequence is FALSE?
a. it is found near the 5’ end of prokaryotic mRNAs.
b. it is complementary to a sequence near the 3’ end of the 16S rRNA.
c. it helps position the small ribosomal subunit near the translation start site.
d. it contains the AUG initiator codon.
e. it is required for efficient translation.
d. It contains the AUG initiator codon
Which of the following methods would be used to determine the amino acid sequence of a peptide?
a. polymerase chain reaction
b. western blotting
c. organism cloning
d. gel shift assay
e. mass spectrometry
e. Mass spectrometry
Mass spectrometry can detect all of these EXCEPT:
a. proteins that have been post-translationally modified.
b. proteins made from mRNAs that have been alternatively spliced.
c. proteins made from mRNAs that have used alternate polyadenylation sites.
d. proteins present in cancer cells but not in normal cells.
e. proteins that have been localized in the wrong cellular compartment.
e. Proteins that have been localized in the wrong cellular compartment.
Which of the following types of mutation is likely to have the greatest consequence to the cell?
a. a G => A change that creates a stop codon within a gene
b. trisomy of an autosome
c. an insertion of a T in a homopolymeric run of Ts
d. an inversion of the long arm of the X chromosome
e. a reciprocal translocation between two autosomes
b. Trisomy of a autosome
A scientist suspects that a short translocation has occurred that might involve a gene that she is
studying. What is the fastest way to determine if the cells carry the translocation?
a. sequence the genome with DNA from the cells
b. use PCR to amplify the gene
c. use a labeled probe of the gene to do in situ hybridization
d. do a chromosome walk with the gene as an initial probe
e. construct a YAC library from the cell’s DNA
c. Use a labeled probe of the gene to do in situ hybridization
Which statement about RNA interference is FALSE?
a. it occurs only in plants.
b. it involves short RNAs that are complementary to the target mRNA.
c. it can inhibit the transcription of the target mRNA.
d. it can cause the degradation of the target mRNA.
e. it can inhibit the translation of the target mRNA.
a. It occurs only in plants
The function of helicases during replication is to:
True / False 14. join the ends of adjacent Okazaki fragments together
True / False 15. separate the DNA strands from each other
True / False 16. relieve tension induced by supercoiling
True / False 17. remove the RNA primers that initiate replication
False 14. join the ends of adjacent Okazaki fragments together
True 15. separate the DNA strands from each other
False 16. relieve tension induced by supercoiling
False 17. remove the RNA primers that initiate replication
Microarrays are useful when studying the gene expression in cancer cells because:
True / False 18. they can identify all of the genes that are overexpressed.
True / False 19. they can identify all of the genes that are underexpressed.
True / False 20. they can identify all of the genes that have point mutations.
True 18. they can identify all of the genes that are overexpressed.
True 19. they can identify all of the genes that are underexpressed.
False 20. they can identify all of the genes that have point mutations.
In partially diploid E. coli cells with the genotype F’ i+ o- z- y+ a-/ chromosome i- o+ z+ y- a+, which
functional gene product(s) would be expressed at high level in the absence of lactose?
True / False 27. β-galactosidase only
True / False 28. β-galactosidase, permease, and transacetylase
True / False 29. permease only
True / False 30. permease and transacetylase
False 27. β-galactosidase only
False 28. β-galactosidase, permease, and transacetylase
True 29. permease only
False 30. permease and transacetylase
Which of the following statements about nucleotides are true and which are false?
True / False 31. The phosphate group is attached to the nitrogenous base.
True / False 32. A nucleotide contains a base, a sugar, and a phosphate group.
True / False 33. The sugar contains two nitrogen atoms.
True / False 34. The nitrogenous base is attached to the sugar by a glycosidic bond.
False 31. The phosphate group is attached to the nitrogenous base.
True 32. A nucleotide contains a base, a sugar, and a phosphate group.
False 33. The sugar contains two nitrogen atoms.
True 34. The nitrogenous base is attached to the sugar by a glycosidic bond.
Histone acetyltransferases act to:
True / False 35. eliminate the positive charge of lysines in histones
True / False 36. increase the compaction of DNA around histones
True / False 37. help the histones reassemble following DNA replication
True / False 38. prevent the translation of histone mRNA molecules
True / False 39. remove covalent modifications on the lysine residues of histones
True 35. eliminate the positive charge of lysines in histones
False 36. increase the compaction of DNA around histones
False 37. help the histones reassemble following DNA replication
False 38. prevent the translation of histone mRNA molecules
False 39. remove covalent modifications on the lysine residues of histones
During protein synthesis, the tRNA synthetase acts to:
True / False 40. attach an amino acid to the anticodon of the tRNA
True / False 41. transcribe the genes encoding tRNAs to produce tRNA molecules
True / False 42. serve as the first initiation factor during ribosome assembly
True / False 43. covalently bind an amino acid to the acceptor stem of the tRNA
True / False 44. cause precursor tRNA molecules to adopt their proper final structure
False 40. attach an amino acid to the anticodon of the tRNA
False 41. transcribe the genes encoding tRNAs to produce tRNA molecules
False 42. serve as the first initiation factor during ribosome assembly
True 43. covalently bind an amino acid to the acceptor stem of the tRNA
False 44. cause precursor tRNA molecules to adopt their proper final structure
The following are tRNA binding sites found within ribosomes: True / False 45. peptidyl site True / False 46. exit site True / False 47. elongation site True / False 48. aminoacyl site
True 45. peptidyl site
True 46. exit site
False 47. elongation site
True 48. aminoacyl site
For which of the following experiments would a DNA microarray be useful?
True / False 49. identifying the binding site for a transcription factor
True / False 50. determining which genes are induced when a chemical is added to a cell’s growth medium
True / False 51. determining which genes are down-regulated in response to heat shock
True / False 52. identifying the site of a DNA inversion
True / False 53. distinguishing between two closely related bacterial subspecies
True 49. identifying the binding site for a transcription factor
True 50. determining which genes are induced when a chemical is added to a cell’s growth medium
True 51. determining which genes are down-regulated in response to heat shock
False 52. identifying the site of a DNA inversion
True 53. distinguishing between two closely related bacterial subspecies
URE is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
D. Transcription
Shine-Dalgarno Sequence is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
E. Translation
tRNA is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
E. Translation
Non-Template strand is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
D. Transcription
AUG codon is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
E. Translation
Primase is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
B. DNA Replication
TATA Box is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
D. Transcription
Splicing is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
C. RNA Processing
Pribnow Box is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
D. Transcription
Hemi-methylated DNA is most closely associated with which of the following?
a. DNA repair
b. DNA replication
c. RNA processing
d. transcription
e. translation
A. DNA Repair
In a gene, the DNA strand that has the same sequence of nucleotides as the mRNA transcribed from
that gene is known as the ________ strand.
non-template OR sense OR coding
The coding sequences in eukaryotic genes that are joined during pre m-RNA splicing are called ________.
Exons
Thymine crosslinked dimers in DNA are usually fixed by which repair mechanism?
Nucleotide excision repair
A Northern blot is used to detect what type of molecule?
RNA
What type of probe(s) is used in a Northern blot?
Nucleic acid: DNA, RNA, oligo, etc
A Southern blot is used to detect what type of molecule?
DNA
What type of probe(s) is used in a Southern blot?
Nucleic acid: DNA, RNA, oligo, etc
A Western blot is used to detect what type of molecule?
Protein
What type of probe(s) is used in a Western blot?
Antibody
In dideoxy DNA sequencing, which carbons on the sugar portion of the nucleotide lack OH
groups?
2’ and 3’
Which base is not found in DNA?
a. adenine
b. cytosine
c. guanine
d. uracil
e. thymine
d. Uracil
Which statements best describe a nucleotide? (More than one may be correct)
a. the phosphate group is attached to the base
b. a nucleotide contains a base, a sugar, and a phosphate group
c. the sugar contains two nitrogen atoms
d. the bases contain extra-cyclic groups such as NH2 or O
e. the base is attached to the sugar by a glycosidic bond
b. a nucleotide contains a base, a sugar, and a phosphate group
d. the bases contain extra-cyclic groups such as NH2 or O
e. the base is attached to the sugar by a glycosidic bond
Which are features of a DNA double helix? (More than one may be correct)
a. the bases interact by covalent bonding
b. the sugar-phosphate backbone is on the outside of the helix
c. each base pair contains either two purines or two pyrimidines
d. the backbones of the two strands run in opposite directions
e. bases are positioned perpendicular to the overall axis of the DNA strand
b. the sugar-phosphate backbone is on the outside of the helix
d. the backbones of the two strands run in opposite directions
e. bases are positioned perpendicular to the overall axis of the DNA strand
Which statements about RNA are false?
a. RNA differs from DNA by containing ribose, not deoxyribose sugars
b. RNA contains uracil instead of thymine
c. RNA secondary structure is more variable than DNA
d. none of these statements are false
d. None of these statements are false
Which RNA polymerase component is required for promoter recognition?
a. alpha (α)
b. beta (β)
c. beta prime (β’)
d. sigma (σ)
e. omega (ω)
d. Sigma (σ)
Attenuation of the trp operon occurs when:
a. the trp repressor binds to the operator
b. the corepressor molecules are released from the repressor
c. specific stem-loop structures form in the RNA
d. the cell lacks charged tryptophan tRNA molecules
e. All of these
c. Specific stem-loop structures form in the RNA
E. coli DNA replication and transcription are similar in that:
a. both use DNA Polymerase III
b. both use dNTPs
c. both require formation of an open bubble to initiate synthesis
d. both require primers to initiate synthesis
e. both make copies of each strand during synthesis
c. Both require the formation of an open bubble to initiate synthesis
Which of the following is the small effector molecule that binds to CAP (catabolic activator protein)?
a. allolactose
b. glucose
c. tryptophan
d. cAMP
e. mediator
d. cAMP
Separating the double helix into single strands during replication requires which protein?
a. DNA polymerase I
b. DNA polymerase II
c. helicase
d. topoisomerase
e. primase
c. Helicase
Leading and lagging strand synthesis differs in that:
a. On the leading strand, synthesis is 5’ to 3’ but 3’ to 5’ on the lagging
b. Leading strand synthesis does not require topoisomerase, unlike lagging strand synthesis
c. The leading strand requires only a single primer, while the lagging strand requires multiple primers
d. Helicases open the leading strand faster than the lagging strand
c. The leading strand requires only a single primer, while the lagging strand requires multiple primers
The technique used to determine that DNA replication occurs semi-conservatively was:
a. X-ray crystallography
b. electron microscopy
c. sequencing
d. equilibrium density-gradient centrifugation
e. microarray analysis
d. Equilibrium density-gradient centrifugation
All of the following are properties of DNA polymerase III except:
a. It completes synthesis of the leading strand before beginning synthesis of the lagging strand
b. It is responsible for incorporating most of the nucleotides in the lagging strand
c. It is responsible for incorporating most of the nucleotides in the leading strand
d. It contains a 3’ to 5’ proofreading activity
e. It has a very low error rate
a. It completes synthesis of the leading strand before beginning synthesis of the lagging strand
If the sequence ACATA mutates to become ACTTA, the A to T alteration is called a:
a. depurination
b. transversion
c. transition
d. tautomeric shift
b. Transversion
Which of these DNA repair mechanisms does not use DNA polymerase during repair?
a. homologous recombinational repair of a double-strand break
b. base excision repair of an apurinic site
c. mitotic mismatch repair
d. photolyase repair of a thymine dimer
e. nucleotide excision repair of a thymine dimer
d. Photolyase repair of a thymine dimer
A tautomeric shift during replication most likely results in a:
a. missense mutation
b. deletion mutation
c. frameshift mutation
d. insertion mutation
e. inversion mutation
a. Missense mutation
Site-directed mutagenesis:
a. can be used to restore a mutant gene back to wild-type sequence
b. can be used to modify the function of a gene
c. can be used to modify the binding site for a repressor in the 5’
untranslated region of a gene
d. all of the above
e. none of the
d. All of the above
Steroids act in transcription regulation by:
a. directly binding and activating RNA Polymerase II
b. binding to and inactivating repressor proteins
c. displacing inhibitor proteins from transcription factors
d. binding to a surface receptor that activates a transcription factor
e. none of the above
c. Displacing inhibitor proteins from transcription factors
Histone acetyltransferases act by:
a. adding phosphate groups to serines of histone proteins
b. adding acetyl groups to serines of histone proteins
c. adding phosphate groups to lysines of histone proteins
d. adding acetyl groups to lysines of histone proteins
e. moving acetyl groups from histone proteins to transcription factors
d. Adding acetyl groups to lysines of histone proteins
Which of the following is not a domain found within transcription factors?
a. zinc finger
b. basic domain
c. cytosine zipper
d. helix-turn-helix
e. glutamine-rich domain
c. Cytosine zipper
A single nucleosome is composed of:
a. Eight histone proteins, linker proteins, and about 146 bp of DNA
b. Eight histone proteins and about 146 bp of DNA
c. Six histone proteins and about 146 bp of DNA
d. Four histone proteins and about 146 bp of DNA
b. Eight histone proteins and about 146 bp of DNA
Which of the following processing events are not used with prokaryotic tRNAs:
a. endonucleolytic cleavage
b. exonucleolytic cleavage
c. base modifications
d. poly-A tailing
d. Poly-A tailing
7-methyl-guanosine is added to mRNA molecules during a processing reaction in eukaryotes. The
unique processing event is a:
a. 3’-5’ triphosphate linkage at the 3’ end of the RNA
b. 2’-5’ triphophate linkage at the 5’ end of the RNA
c. 3’-5’ triphosphate linkage at the 5’ end of the RNA
d. 3’-2’ triphosphate linkage at the 3’ end of the RNA
e. 5’-5’ triphosphate linkage at the 5’ end of the RNA
e. 5’-5’ triphosphate linkage at the 5’ end of the RNA
During splicing in precursor mRNA in mammalian cells, the first RNA cleavage step involves:
a. the covalent linkage of the branch site adenine to the 5’ end of the intron
b. covalent linkage of the 5’ end of the second exon with the 3’ end of the branch site
c. hydrogen bonding of the guanosine at the branch site with the 3’ exon end
d. hydrogen bonding of the adenine at the branch site with the 5’ intron
e. disulfide bridging of the 5’ and 3’ ends of the intron
a. The covalent linkage of the branch site adenine to the 5’ end of the intron
Eukaryotic tRNA molecules have a CCA sequence at their 3’ terminus because:
a. that sequence is the anticodon sequence
b. that sequence is added by a nucleotidyl transferase
c. that sequence is a signal sequence for RNA polymerase binding
d. that sequence is a termination signal for the RNaseD exonuclease
e. that sequence is required for an internal hairpin to form
b. The sequence is added by a nucleotidyl transferase
Tandem mass spectrometry can be used to find out:
a. the nucleotide sequence of an mRNA
b. the nucleotide sequence of a gene
c. the amino acid sequence of a protein
d. the composition of a multi-protein complex
c. The amino acid sequence of a protein
How many different reading frames are present in a DNA sequence?
a. one
b. two
c. three
d. six
e. none of the above
d. Six
A microarray used to study gene expression is hybridized with:
a. total RNA from a specific cell type
b. protein from a specific cell type
c. cDNA from a specific cell type
d. PCR-generated oligonucleotides using genomic DNA templates
c. cDNA from a specific cell type
You are investigating a protein complex, and have isolated one protein and raised antibodies to it. You suspect it interacts directly with another protein. The easiest and fastest way to determine if the interaction does occur is to do a: a. ChIP-chip b. tandem mass spectrometry analysis c. Western blot d. immunoprecipitation e. two-hybrid analysis
d. Immunoprecipitation
What is the role of sigma factor?
a. it recognizes the termination signal
b. it stays associated with RNA polymerase at all times
c. it recognizes conserved sequences in the promoter
d. all these are roles of sigma factor.
c. It recognizes conserved sequences in the promoter
In E. coli cells, the level of cyclic AMP is determined by:
a. the presence of an F factor
b. the glucose concentration
c. the lactose concentration
d. the allolactose concentration
e. the total amount of cellular RNA
b. The glucose concentration
E. coli cells that are growing in a medium that is rich in glucose cannot be induced to express the enzyme β-galactosidase, even when lactose is added to the medium. This repression is due to:
a. irreversible binding of the lac repressor protein to the operator b. failure of the transcription termination mechanism c. induction of the lacI gene by glucose d. failure of the Catabolite Activator Protein/cyclic AMP complex to bind the lac promoter e. a conformational change in the lac repressor protein due to an interaction with glucose
d. Failure of the Catabolite Activator Protein/cyclic AMP complex to bind the lac promoter
Attenuation at the trp operon in E. coli occurs when:
a. translation and transcription become uncoupled b. high tryptophan levels inhibit the binding of a repressor protein c. low tryptophan levels increase the rate of RNA polymerase progression d. high tryptophan levels allow the formation of a terminator stem-loop in the trpL mRNA e. the tryptophan membrane transporter increases the rate of tryptophan import
d. High tryptophan levels allow the formation of a terminator stem-loop in the trpL mRNA
Which of the following is NOT a common method of gene regulation in eukaryotes?
a. histone modification b. attenuation c. nucleosome spacing alterations d. RNA processing
b. Attentuation
Which of the following statements is NOT correct?
a. the consensus sequence for the eukaryotic polyadenylation signal is AAUAAA b. the typical length of a poly A tail in humans is 200-250 nucleotides c. polyA polymerase adds adenine nucleotides to the 5' end d. polyadenylation is important for the stability of a mRNA e. endonuclease cleavage occurs about 20 nucleotides downstream of the polyadenylation signal
c. polyA polymerase adds adenine nucleotides to the 5’ end
Which statement about pre-mRNA introns is true?
a. They are removed by cutting and joining the DNA b. They are never removed; the ribosome skips them when making protein c. They contain short consensus sequences at both ends d. They are removed after the mRNA has been transported to the cytoplasm e. None of these statements are true
c. They contain short consensus sequences at both ends
Which statement about small nuclear ribonucleoprotein particles (snRNPs) is false?
a. They contain both RNA and protein components b. They bind to specific sites in the pre-mRNA c. They interact with Group I self-splicing introns d. They interact with each other to form an active spliceosome e. None of these statements are false
c. They interact with Group I self-splicing introns
Transcription is similar to DNA replication in that it….
True / False 11. requires a DNA template
True / False 12. requires a primer to initiate synthesis
True / False 13. begins at specific sites in the genome
True / False 14. requires the step-wise formation of a multi-component complex to initiate
True / False 15. synthesizes a new strand in the 5’ to 3’ direction
True 11. requires a DNA template
False 12. requires a primer to initiate synthesis
True 13. begins at specific sites in the genome
True 14. requires the step-wise formation of a multi-component complex to initiate
True 15. synthesizes a new strand in the 5’ to 3’ direction
The following are DNA binding domains used in transcription factors:
True / False 16. zinc finger
True / False 17. helix-turn-helix
True / False 18. basic domain
True / False 19. disulfide bridge
True / False 20. glutamine-rich domain
True 16. zinc finger True 17. helix-turn-helix True 18. basic domain False 19. disulfide bridge False 20. glutamine-rich domain
Indicate True or False for each statement about the Carboxy Terminal Domain of RNA polymerase II:
True / False 21. it is phosphorylated by TFIIH
True / False 22. its phosphates are removed when transcription elongation begins
True / False 23. capping factors bind when it is dephosphorylated
True / False 24. splicing factors bind when it is phosphorylated
True / False 25. polyadenylation factors bind when it is phosphorylated
True 21. it is phosphorylated by TFIIH
False 22. its phosphates are removed when transcription elongation begins
False 23. capping factors bind when it is dephosphorylated
True 24. splicing factors bind when it is phosphorylated
True 25. polyadenylation factors bind when it is phosphorylated
For which of the following experiments would a DNA microarray be useful?
True / False 26. identifying the binding site for a transcription factor
True / False 27. determining if a transition mutation occurred in a gene during replication
True / False 28. determining which genes are down-regulated in response to heat shock
True / False 29. identifying the site of a DNA inversion
True / False 30. distinguishing between two closely related bacterial subspecies
True 26. identifying the binding site for a transcription factor
False 27. determining if a transition mutation occurred in a gene during replication
True 28. determining which genes are down-regulated in response to heat shock
False 29. identifying the site of a DNA inversion
True 30. distinguishing between two closely related bacterial subspecies
