Molecular Biology Exam 2

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Molecular Biology Quizzes & Trivia
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  • 1. 
    Which of the following is not present in the core RNA polymerase? 
    • A. 

      B (Beta)

    • B. 

      B' (Beta prime)

    • C. 

      Sigma (o)

    • D. 

      Both (Beta) and (sigma)


  • 2. 
    An experiment was designed to obtained nonspecific transcription from both strands of a DNA molecule. Which of the following strategies would be most effective in achieving this? 
    • A. 

      Include the RNA holoenzyme in the reaction.

    • B. 

      Use the core enzyme of RNA polymerase

    • C. 

      Enrich the preparation with sigma subunit

    • D. 

      Use intact DNA.

    • E. 

      Include the RNA holoenzyme in the reaction and use the core enzyme of RNA polymerase are both effective


  • 3. 
    Which of the following techniques would be most useful in testing the ability of the core RNA polymerase to bind to promoter? 
    • A. 

      Gel filtration

    • B. 

      S1 mapping

    • C. 

      Immunoblotting

    • D. 

      DNase footprinting

    • E. 

      Northern blotting


  • 4. 
    Which of the following statements is false regarding the sigma-factor? 
    • A. 

      It does not have a DNA-binding domain

    • B. 

      Interaction with the core enzyme unmasks the DNA-binding region

    • C. 

      Subregions 2.4 and 4.4 are involved in promoter recognition.

    • D. 

      It can also bind to the nontemplate strand.

    • E. 

      It can bind to the -10 box.


  • 5. 
    Which of the following is true about the holoenzyme of RNA pol in an open complex? 
    • A. 

      The DNA is bound mainly to the sigma-subunit

    • B. 

      There no interaction between the sigma factor and the -10 region.

    • C. 

      There are two Na+ ions in the core enzyme

    • D. 

      Region 2.4 of the sigma-factor binds the the -35 region.

    • E. 

      The DNA is bound mainly to the sigma-subunit and there no interaction between the sigma factor and the -10 region.


  • 6. 
    Dimethyl sulfate is used to 
    • A. 

      Cleave DNA molecules

    • B. 

      Denature or melt DNA promote region

    • C. 

      Remove methyl groups from RNA

    • D. 

      Add methyl groups to DNA

    • E. 

      Promote the binding of RNA polymerase to DNA


  • 7. 
    Which of the following would most likely occur if an in vitro transcription assay is preformed by using a cell extract containing an (alpha) a subunit without the C-terminal domain? 
    • A. 

      Polymerase would become tightly associated with the promoter

    • B. 

      Polymerase would become more susceptible to proteolysis

    • C. 

      Transcription will be accelerated

    • D. 

      Polymerase complex would be loosely associated with the promoter

    • E. 

      Recognition of the UP element would be faster


  • 8. 
    Place the following in the order that they occur during transcription initiation: 1- formation of open complex2- formation of closed complex3- promoter clearance4- synthesis of about 10 nucleotides 
    • A. 

      1,2,3,4

    • B. 

      2,1,4.3

    • C. 

      2,1,2,4

    • D. 

      3,1,2,4

    • E. 

      3,2,1,4


  • 9. 
    Which of the following techniques is suitable for the study of DNA:RNA hybrid formation during transcription? 
    • A. 

      DNA: protein crosslinking

    • B. 

      DNAase I footprinting

    • C. 

      DNA: RNA crosslinking

    • D. 

      Two-dimensional PAGE

    • E. 

      FRET analysis


  • 10. 
    Which of the following are characteristic of intrinsic terminator elements? 
    • A. 

      They contain an inverted repeat

    • B. 

      They contain a hairpin loop

    • C. 

      They contain several T's in the nontemplate strand of DNA

    • D. 

      Only they contain an inverted repeat and they contain a hairpin loop are correct

    • E. 

      They contain an inverted repeat, they contain a hairpin loop, and they contain several T's in the nontemplate strand of DNA.


  • 11. 
    Which of the following is incorrect regarding rho dependent terminators? 
    • A. 

      They contain several T's in the non-template strand

    • B. 

      They consist of inverted repeats

    • C. 

      They form hairpin loops

    • D. 

      Rho binds to the growing transcripts

    • E. 

      Rho has no helicase activity


  • 12. 
    Which of the following does not have a DNA-binding domain? 
    • A. 

      Sigma-factor

    • B. 

      UP region

    • C. 

      Alpha-factor

    • D. 

      Beta

    • E. 

      Beta prime


  • 13. 
    Which of the following bond is lactose links between glucose and galactose? 
    • A. 

      It is a glycoside bond

    • B. 

      The linkage is through (beta)-1, 4 bond

    • C. 

      It can be broken by (beta)-galactosidase

    • D. 

      It is a covalent bond

    • E. 

      All of the choices are correct


  • 14. 
    If an operon is under negative control it means that the operon is never operational
    • A. 

      True

    • B. 

      False


  • 15. 
    In the absence of glucose there will be a rapid accumulation of lactose in the following mutant: I- Oc Z+ Y-I- O+ Z+ Y-
    • A. 

      True

    • B. 

      False


  • 16. 
    The following is an example of a cis-dominant mutation: I-d O+ Z+ Y+ A-
    • A. 

      True

    • B. 

      False


  • 17. 
    Which of the following statements is true about a lac operon with the following genotype? I- Oc Z+ Y-I- O+ Z- Y-
    • A. 

      A repressor protein will be constitutively produced

    • B. 

      (Beta)- galactosidase will be constitutively produced

    • C. 

      A trans-dominant mutation is present

    • D. 

      Permease will be constitutively produced

    • E. 

      Both a repressor protein will be constitutively produced and a cis-dominant mutation is present


  • 18. 
    Which of the following plasmids could be used to restore inducible regulation of (Beta)-galatosidase in this mutatnt: I+ Oc Z- Y+ A+? 
    • A. 

      I+ Oc Z- Y+ A+

    • B. 

      I+Oc Z- Y- A-

    • C. 

      I- O+ Z+ Y+ A+

    • D. 

      I- Oc Z+ Y+ A+

    • E. 

      Both I+ Oc Z- Y+ A+ and I+ Oc Z- Y- A- are correct


  • 19. 
    Which of the following organisms would produce functional lac products in the presence of IPTG? 
    • A. 

      Is Oc Z- Y+ A+

    • B. 

      Is Oc Z- Y- A-

    • C. 

      I+ O+ Z+ Y+ A+

    • D. 

      I- Oc Z+ Y+ A+

    • E. 

      Both Is Oc Z- Y+ A+ and Is Oc Z- Y+ A+ are correct


  • 20. 
    Which of the followign statements is true about a lac operon with this genotype? I-d O+ Z+ Y- A- 
    • A. 

      The operon is repressible

    • B. 

      The operon is nonrepressible

    • C. 

      The mutation is cis-dominant

    • D. 

      The operon is uninducible

    • E. 

      None of the choices is correct


  • 21. 
    Which of the following techniques is most useful in determining if RNA polymerase has initiated transcription form the lac DNA template? 
    • A. 

      Southern analysis

    • B. 

      DNA fingerprinting

    • C. 

      Run-off transcription assay

    • D. 

      DNA sequencing

    • E. 

      RACE


  • 22. 
    In an in vitro transcription assay to detect the level of transcription from a lac operon, one of the RNA precursors was tagged with a fluorescent label on the y-phosphate. Which of the following is a likely outcome if transcription occurred? 
    • A. 

      The level of fluorescence would increase along the new RNA strand

    • B. 

      Each RNA would have a fluorescent tag on every other nucleotide.

    • C. 

      The level of fluorescence would be very high in the assay buffer

    • D. 

      No fluorescence would be detected in the buffer at the end of the assay

    • E. 

      All of the choices are possible


  • 23. 
    Which of the following is mostly likely to occur if the level of glucose is low in a bacterial cell? 
    • A. 

      Cyclic-AMP levels will be depressed

    • B. 

      CAP will assist in stimulating transcription of the lac operon if lactose is added

    • C. 

      CRP activity will be inhibited

    • D. 

      Both Cyclic-AMP levels will be depressed and CRP activity will be inhibited

    • E. 

      None of the choices is correct


  • 24. 
    Which of the following is true about the action of CAP at the lac promoter? 
    • A. 

      CAP monomer binds directly tot he promoter stimulating polymerase to bind

    • B. 

      CAP-AMP blocks recruitment of polymerase to the promoter

    • C. 

      CAP blocks the (alpha) CTD of RNA polymerase

    • D. 

      Binding of the CAP-cAMP to thelac activator-binding site recruits RNA polymerase

    • E. 

      CAP monomer binds directly to the promoter stimulating polymerase to bind and CAP blocks the (alpha) CTD of RNA polymerase


  • 25. 
    Which of the following is true about the regulation of the trp operon? 
    • A. 

      An aporepressor is involved

    • B. 

      A corepressoris involved

    • C. 

      Attenuation is one of the control mechanisms.

    • D. 

      Negative control is involved

    • E. 

      All of the choices are true


  • 26. 
    Which of the following is absent in an operon? 
    • A. 

      Operator

    • B. 

      Promoter

    • C. 

      Intron

    • D. 

      Both operator and promoter

    • E. 

      Both promoter and intron


  • 27. 
    Recent experimental evidence has shown that only one operator sequence is needed for maximal expression 
    • A. 

      True

    • B. 

      False


  • 28. 
    One hypothesis explaining the mechanism of repression of the lac operon states that the repressor binds the operator and blocks access by the polymerase to the adjacent promoter
    • A. 

      True

    • B. 

      False


  • 29. 
    CAMP level is increased by the presence of high level of glucose 
    • A. 

      True

    • B. 

      False


  • 30. 
    Arabibinose can derepress the ara operon by causing AraC to loosen its attachement to araO2 and to bind to araI2 instead. 
    • A. 

      True

    • B. 

      False


  • 31. 
    Attenuation causes the length of the RNA molecules to be significantly extended. 
    • A. 

      True

    • B. 

      False


  • 32. 
    The following conditions lead to a change in gene expression patterns in bacterial cells 
    • A. 

      Sporulation

    • B. 

      Heat shock

    • C. 

      Nutrient availability

    • D. 

      Nitrogen deprivation

    • E. 

      Phage infection


  • 33. 
    Which of the following sigma specificity factor is involved in middle gene transcription during SPO1 phage infection of bacteria?
    • A. 

      Gp33

    • B. 

      Gp28

    • C. 

      Gp34

    • D. 

      Gp43

    • E. 

      Host sigma


  • 34. 
    Which of the following is true about the early phase of T7 infection of bacteria?
    • A. 

      Class II genes are the first to be transcribed

    • B. 

      The host polymerase transcribes class II genes

    • C. 

      The phage-encoded polymerase transcribes the class I phage genes

    • D. 

      Class I genes are the first to be transcribed

    • E. 

      All of the choices are correct


  • 35. 
    Differences in transcription of T7 and SPO1 genes are 
    • A. 

      T7 phage encodes a new RNA polymerase for phage genes

    • B. 

      SPO1 phage uses the new sigma factor for phage gene

    • C. 

      Both correct

    • D. 

      Both wrong

    • E. 

      They have the same factors


  • 36. 
    Which of the following conditions does not lead to a change in gene expression patterns in bacteria cells? 
    • A. 

      Sporulation

    • B. 

      Heat shock

    • C. 

      Nutrient availability

    • D. 

      Nitrogen deprivation

    • E. 

      None of the choices are correct


  • 37. 
    Predict the outcome of the removal of the N form the DNA sequence of the (lamda) phage:
    • A. 

      Lysogenic cycle will be induced

    • B. 

      Entry into the bacterial host will be blocked

    • C. 

      Antitermination will be affected

    • D. 

      Transcription form the left promoter will be interrupted

    • E. 

      Antitermination will be affected and transcription form the left promoter will be interrupted


  • 38. 
    Which of the following is a possible mechanism for the action of NusA in termination? 
    • A. 

      It binds to the RNA polymerase causing it to stall.

    • B. 

      It stimulates termination at intrinsic terminator by facilitating hairpin loop formation

    • C. 

      It binds to NusB to promote detachment of the RNA polymerase for the DNA template

    • D. 

      It interacts with S10 to promote dissociation of the RNA polymerase

    • E. 

      It binds to the RNA polymerase causing it to stall and it stimulates termination at intrinsic terminator by facilitating hairpin loop formation


  • 39. 
    Which of the following is involved in maintaining lysogeny in (lamda) phage? 
    • A. 

      P (RE)

    • B. 

      P (RM)

    • C. 

      P (RL)

    • D. 

      P (RO)

    • E. 

      All of the choices are correct


  • 40. 
    Which of the following operators is a target of CI gene production? 
    • A. 

      O RI

    • B. 

      O R2

    • C. 

      O L1

    • D. 

      O L2

    • E. 

      All of the choices are correct


  • 41. 
    Which of the following is true about the interaction with the (lamda) reppressor and RNA polymerase at P (RM)? 
    • A. 

      Interaction b/w repressor and polymerase is essential for activation of transcription

    • B. 

      Interaction involves region 4 of sigma-factor

    • C. 

      Interaction can be disrupted by the binding of CIII.

    • D. 

      Interaction between repressor and polymerase is essential for activation of transcription and interaction involves region 4 of sigma factor

    • E. 

      Interaction between repressor and polymerawse is essential for activation of transcription and interaction can be disrupted by the bidning of CIII.


  • 42. 
    Which of the following is true about the cro gene? 
    • A. 

      It must be stimulated during lysogeny

    • B. 

      Its product promotes repressor activity

    • C. 

      Cro repression is important to lysogeny

    • D. 

      It is adjacent to the cIII gene

    • E. 

      It must be stimulated during lysogeny and its products promotes repressor activity


  • 43. 
    During an experiment to study the rate of infection of bacteria with T4, the bacteria with T4, the bacterial cultures were accidentally exposed to a UV light source. Which of the following would be expected for this exposure? 
    • A. 

      RecA gene is turned off

    • B. 

      Coprotease activity in RecA protein is activated

    • C. 

      SOS response is induced

    • D. 

      Coprotease activity in RecA protein is activated and SOS response is induced

    • E. 

      RecA gene is turend off and coprotease activity in RecA protein is activated are correct


  • 44. 
    You were asked to choose a method to separate a mixture of eukaryotic polymerases. Which of the following methods would you choose? 
    • A. 

      Chromatography

    • B. 

      Western blotting

    • C. 

      S1 nuclease assay

    • D. 

      DNASE 1 footprinting

    • E. 

      Chromatography and UMP incorporation assay


  • 45. 
    Why three RNA polymerases? How many types of RNA in the cells? 
    • A. 

      RRNA: 28S, 18s, 5.8S, 5s

    • B. 

      MRNA

    • C. 

      TRNA

    • D. 

      Small nuclear RNA or snRNA

    • E. 

      Other RNAs


  • 46. 
    Which of the following are products of RNA polymerase II activity? 
    • A. 

      TRNA

    • B. 

      SnRNA

    • C. 

      HnRNA

    • D. 

      TRNA and snRNA

    • E. 

      SnRNA and hnRNA


  • 47. 
    Which of the following products are made by RNA polymerase III? 
    • A. 

      7SL RNA

    • B. 

      5SrRNA

    • C. 

      SnRNA

    • D. 

      7SL RNA and 5S rRNA and U6 snRNA

    • E. 

      7SL RNA, 5S rRNA and snRNA


  • 48. 
    Which of the following statements about ribosomal genes is incorrect? 
    • A. 

      They have a higher GC content compared to other nuclear genes.

    • B. 

      They have a different base composition compared to other nuclear genes.

    • C. 

      There are no repetitive sequences

    • D. 

      They are found in the nucleolus

    • E. 

      They are transcribed by RNA polymerases I and III


  • 49. 
    An antibody was produced and used in an immunohistochemical assay to detect the location of RNA polymerase I in a thin section of a liver biopsy. The section was antibody-labeled with a fluorescent tag, then viewed under a fluorescent microscope. State where you would expect to find positive staining if the enzymes is present. 
    • A. 

      Rough endoplasmic reticulum

    • B. 

      Nucleolus

    • C. 

      Endoplasmic reticulum

    • D. 

      Ribosomes


  • 50. 
    A new mutant cell line was developed and was found to be defective in polymerase III activity. Which of the following is likely to be observed in this cell line? 
    • A. 

      There will be an overabundance of secreted proteins

    • B. 

      Splicing function is impaired

    • C. 

      There will be an overproduction of 7 SL RNA

    • D. 

      There will be an overabundance of secreted proteins and splicing function is impaired function is impaired are correct.

    • E. 

      There will be an overabundance to secreted proteins, splicing function is impaired, and there will be an overproduction of 7 SL RNA are correct.


  • 51. 
    An experiment is planned to study the effect of reducing the transcription of the myosin gene. Which of the following inhibitiors wold be useful in this study? 
    • A. 

      (alpha)-amanitin

    • B. 

      DMS

    • C. 

      Heparin

    • D. 

      Ammonium sulfate

    • E. 

      None of the choices are correct


  • 52. 
    Which of the following would you choose to study the role of polymerase subunits in elongation? 
    • A. 

      Epitope tagging

    • B. 

      Immunoprecipitation

    • C. 

      In vitro transcription

    • D. 

      Western blotting

    • E. 

      DNAase footprinting


  • 53. 
    Which of the following would you choose to specifically collect polymerase subunits in cell extracts? 
    • A. 

      Epitope tagging

    • B. 

      Immunoprecipitation

    • C. 

      In vitro transcription

    • D. 

      Western blotting

    • E. 

      DNAase footprinting


  • 54. 
    Which of the following is not a part of the core class II promoter? 
    • A. 

      TATA box

    • B. 

      Upstream element

    • C. 

      BRE

    • D. 

      DPE

    • E. 

      Inr


  • 55. 
    Which of the following techniques would you use to study the role of the BRE? 
    • A. 

      S1 nuclease protection analysis

    • B. 

      Linker scanning mutations

    • C. 

      X-ray crystallography

    • D. 

      S1 nuclease protection analysis and linker scanning mutations

    • E. 

      Linker scanning mutations and X-ray crystallography


  • 56. 
    Which statement is wrong regarding promoter in humans? 
    • A. 

      Promoter lies before the gene

    • B. 

      Promoter is recognized by RNA polymerase

    • C. 

      Promoter can be never within a gene

    • D. 

      Class III promoter in type I genes is recognized by RNA polymerase

    • E. 

      Bacterial promoters have the same function as the humans'


  • 57. 
    Predict a possible effect of deleting the enhancers region of the polymerase I gene. 
    • A. 

      Reduced transcription of ribosomes

    • B. 

      Reduction in the production of most hnRNAs

    • C. 

      Reduction in the amount of rRNA made

    • D. 

      Reduction in the production of Rpb1

    • E. 

      Reduction in the production of Rpb2


  • 58. 
    Eukaryotic ribosomal RNA gene are transcribed by RNA polymerase II
    • A. 

      True

    • B. 

      False


  • 59. 
    Roeder and Rutter showed that there are four polymerases operating in the eukaryotic cell 
    • A. 

      True

    • B. 

      False


  • 60. 
    Epitope taggin is an efficicent way to immunoprecipate to isolate an entire polymerase complex. 
    • A. 

      True

    • B. 

      False


  • 61. 
    Which of the following is the correct order of addition of general transcription factors to the initiation complex? 
    • A. 

      TFIIA+TFIID, TFIIE, TFIIIIB, TFIIF + pol II, TFIIH

    • B. 

      TFIIA + TFIID, TFIIB, TFIIH, TFIIF + pol II, TFIIE

    • C. 

      TFIIA+TFIID, TFIIH, TFIIIIB, TFIIF + pol II, TFIIE

    • D. 

      TFIIA + TFIID, TFIIH, TFIIIIB, TFIIF + pol II, TFIIE

    • E. 

      TFIIA + TFIID, TFIIIIB, TFIIF + pol II, TFiIE, TFIIH


  • 62. 
    An electrophoretic mobility shift assay (EMSA) was conducted to check for the binding of TFIIB to a segment of a DNA promoter region. Which of the following approaches could be used to confirm that TFIIB is indeed binding? 
    • A. 

      Use an antibody to TFIIB and check for a supershift by EMSA.

    • B. 

      Complete TFIIB binding with TFIID

    • C. 

      Conduct a nuclear run-off assay

    • D. 

      Use an antibody to TFIIB and check for a supershift by EMSA and complete TFIIB binding with TFIID are correct.

    • E. 

      Complete TFIIB binding with TFIID and conduct a nuclear run-off assay are correct.


  • 63. 
    You are planning an experiment to look at the specific binding of the TBP to the promoter. Which of the following would be a suitable negative control for this experiment? 
    • A. 

      A DNA sequence made with multiple cytosines

    • B. 

      A DNA strand containing the TATA box linked to multiple adenine

    • C. 

      A DNA strand containing the TATA box linked to multiple guanines

    • D. 

      A DNA sequence made with multiple cytosines and a DNA strand containing the TATA box linked to multiple adenine

    • E. 

      A DNA sequence made with multiple cytosines, a DNA strand containing the TATA box linked to multiple adenine, a DNA strand containing the TATA box linked to multiple guanines


  • 64. 
    Which of the following would you expect to bind to a chromatography column made of a resin conjugated to UBF? 
    • A. 

      Sp1

    • B. 

      SL1

    • C. 

      TFIIB

    • D. 

      TFIIH

    • E. 

      TFIIE


  • 65. 
    Determine which of the following would most likely lead to a dramatic reduction in transcription. 
    • A. 

      Absence of the TATA box

    • B. 

      Removal of some TAFs

    • C. 

      Removal of TAFII250

    • D. 

      Absence of the TATA box and removal of some TAFs

    • E. 

      None of the choices are correct


  • 66. 
    TFIID collaborates with TFIIA to bind to the TATA box.
    • A. 

      True

    • B. 

      False


  • 67. 
     RNA polymerase prevents the binding of TFIIF to the promoter region
    • A. 

      True

    • B. 

      False


  • 68. 
    A promoter region replacing the TATA box with the ICIC box will not bind to TFIID. 
    • A. 

      True

    • B. 

      False


  • 69. 
    Which of the following are typical features of transcriptional activators? 
    • A. 

      Transcriptional activators?

    • B. 

      DNA-binding domain

    • C. 

      Kinase domain

    • D. 

      Transcription-activation domain and DNA-binding domain

    • E. 

      Transcription activation domain and kinase domain


  • 70. 
    Which of the following can be found in DNA-binding domains? 
    • A. 

      Zinc fingers

    • B. 

      Glutamine-rich regions

    • C. 

      BZIP motifs

    • D. 

      BHLH motif

    • E. 

      All of the choices are correct


  • 71. 
    Select the feature that is not true of the GAL4 protein. 
    • A. 

      Contains six cysteines

    • B. 

      Contains zinc fingers

    • C. 

      Contains zinc ions in the DNA binding motif

    • D. 

      Contains (alpha)-helix

    • E. 

      Is a member of zinc-containing family


  • 72. 
    Which of the following is a target site for GAL4?
    • A. 

      UAS (G)

    • B. 

      CCAATT

    • C. 

      GCAAT

    • D. 

      UAS (G) and CCAAT

    • E. 

      CCAAT and GCAAT


  • 73. 
    One effect of mutation or deleting the activation domain of a transcriptional activator would be 
    • A. 

      Reduction in the binding of TFIIA

    • B. 

      Reduction in the binding TFIID

    • C. 

      Binding of the activator to DNA, without activating transcription

    • D. 

      Reduction in the binding of TFIIA and reduction in the binding TFIID

    • E. 

      Reduction in the bindign TFIID and binding of the activator to DNA, without activating transcription


  • 74. 
    The glucocorticoid receptor is activated by binding to 
    • A. 

      Its hormone ligand then moving to the nucleus

    • B. 

      Its protein partner and then moving to the nucleus

    • C. 

      Its partner in the nucleus

    • D. 

      DNA and then to its hormone ligand.

    • E. 

      None of the choices are correct


  • 75. 
    Which of the following is a reasonable way to explain the ability of enhancers to act at a distance? 
    • A. 

      The activator binds to an enhancer, changing the supercoiling state of the DNA and opening up the promoter to general transcription factors.

    • B. 

      The activator binds to an enhancer, slides along the DNA until it encounters the promoter, and activates transcription

    • C. 

      An activator binds to an enhancer, creating loops in the DNA, which leads to the interaction of proteins at the promoter and activation of transcription.

    • D. 

      An activator binds to an enhancer and a downstream segment to form a loop, which causes the protein to track toward the promoter and activate transcription.

    • E. 

      All of the choices explanations are possible


  • 76. 
    HMG (Y) plays a role in IFN-(beta) transcription by
    • A. 

      Bending the DNA, causing more activators to bind and interact with each other to enhance transcription

    • B. 

      Suppressing IFN-(beta) expression during a viral infection

    • C. 

      Binding to the HMG domain of LEF

    • D. 

      Bending the DNA, causing more activators to bind and interact with each other to enhance transcription and suppressing IFN-(beta) expression during a viral infection

    • E. 

      Suppressing IFN-(beta) expression during a viral infection and binding to the HMG domain of LEF.


  • 77. 
    Insulators are DNA elements that 
    • A. 

      Shield genes from activation by blocking enhancer activity

    • B. 

      Block gene activity by binding the operator regions.

    • C. 

      Block the coding region of genes, preventing transcription

    • D. 

      Shield genes from activation by blocking enhancer activity and block gene activity by binding the operator regions

    • E. 

      Block gene activity by binding the operator regions and block the coding region of genes, preventing transcription.


  • 78. 
    Which of the following histone protein is the most highly conserved from one organism to another? 
    • A. 

      H1

    • B. 

      H2A

    • C. 

      H2B

    • D. 

      H3

    • E. 

      H5


  • 79. 
    Which of the following is the correct order of chromatin folding? 
    • A. 

      Nucleosome formation, 30 nM fiber formation, radial loop structure

    • B. 

      Radial loop structure, 30 nM fiber formation, nucleosome formation

    • C. 

      30 nM fiber formation, nucleosome formation, radial loop formation

    • D. 

      30 nM fiber formation, radial loop formation, nucleosome formation

    • E. 

      Nucleosome formation, radial loop formation, nucleosome formation


  • 80. 
    Studying Xenopus transcription of somatic and oocyte 5s-rRNA genes, Donald Browna nd colleagues demonstrated that the difference in the expression patterns in the two types of cell could be seen as a race between 
    • A. 

      Histones and transcription factors

    • B. 

      Transcription factors and RNA Pol III

    • C. 

      RNA Pol III and repressors

    • D. 

      Histones and enhancer elements

    • E. 

      Histones and DNA gyrase


  • 81. 
    One method to demonstrate existence of nucleosome free DNA regions is 
    • A. 

      RNA Polymerase Run-off experiments

    • B. 

      Nuclear Run of experiments

    • C. 

      Reporter gene experiments

    • D. 

      Anion Exchange chromatography

    • E. 

      DNase hypersensitivity experiments


  • 82. 
    Histone acetylation can occur in the 
    • A. 

      Nucleus

    • B. 

      Cytoplasm

    • C. 

      ER lumen

    • D. 

      Nucleus and cytoplasm

    • E. 

      Nucleus, cytoplasm, and ER lumen


  • 83. 
    The Histone Code states that the 
    • A. 

      Primary sequence of the histone proteins never changes over time

    • B. 

      Combination of histone modification on a given nucleosome near a gene's control region affects the efficiency of transcription of that gene

    • C. 

      Combination of histone modification on a given nucleosome near a gene's contorl region affects the efficiency of transcription of all the nearby genes.

    • D. 

      Lysines are the only amino acids found in histones that can be acetylated and deacetylated

    • E. 

      Histones are found in all living cells


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