Molecular Biology Exam Iii

66 Questions  I  By Ekanye
Please take the quiz to rate it.

Molecular Biology Quizzes & Trivia
This exam cover chapters 14,15,17, 18 and 24

  
Changes are done, please start the quiz.


Questions and Answers

Removing question excerpt is a premium feature

Upgrade and get a lot more done!
  • 1. 
    Which of the following experiments was useful in determing the existence of introns in the adenovirus genome?
    • A. 

      DNA/DNA hybridization

    • B. 

      RNA/RNA hybridization

    • C. 

      R-looping experiments

    • D. 

      RT-PCR

    • E. 

      CDNA cloning experiments


  • 2. 
    You have isolated a new species of mRNA using an oligo-dT column. You then perform an R-looping experiment to determine if the gene encoding for your mRNA contains introns. Below is a representation of the electron micrograph results. Which of the followign can you conclude from your experiment?
    • A. 

      The gene contains no introns

    • B. 

      The gene contains one intron

    • C. 

      The gene contains two introns

    • D. 

      The gene contains three introns

    • E. 

      The results are inconclusive


  • 3. 
    The first two bases and the last two bases in the splicing signal consensus sequence are
    • A. 

      GT-AG

    • B. 

      GU-AG

    • C. 

      CU-AG

    • D. 

      GU-AC

    • E. 

      GT-TG


  • 4. 
    Which of the following is the name for the YEAST 40s particle where mRNA splicing takes place?
    • A. 

      Ribosome

    • B. 

      Nucleolus

    • C. 

      Spliceosome

    • D. 

      HnRNA

    • E. 

      R-loop


  • 5. 
    "Snurps" or snRNPs are composed of
    • A. 

      RNA

    • B. 

      Protein

    • C. 

      DNA

    • D. 

      RNA and protein

    • E. 

      DNA and RNA


  • 6. 
    The catalytic center of the spliceosome appears to include
    • A. 

      Mg2+

    • B. 

      U2 and U6 snRNP

    • C. 

      The branch point region of the intron

    • D. 

      Mg2+ and the branch point region of the intron

    • E. 

      Mg2+, U2, and U6 snRNP, and the branch point region of the intron


  • 7. 
    Which of the following is the first snRNP to bind during the assembly stage of the spliceosome cycle?
    • A. 

      U1

    • B. 

      U2

    • C. 

      U4

    • D. 

      U5

    • E. 

      U6


  • 8. 
    Which of the following snRNP is mismatched with its function?
    • A. 

      U1: base pairs with 5' splice site of mRNA

    • B. 

      U2: base pairs witht he conserved sequence at splicing branch point

    • C. 

      U4: base pairs with 3' splice site of mRNA

    • D. 

      U5: associates with last nucleotide in one exon and the first nucleotide in the next exon.

    • E. 

      U6: base pairs with 5' end of the intron


  • 9. 
    The binding of which of the following snRNPs to spliceosome requires ATP?
    • A. 

      U1

    • B. 

      U2

    • C. 

      U4

    • D. 

      U5

    • E. 

      U6


  • 10. 
    Spliceosomal lariat is
    • A. 

      Cowboy's lasso

    • B. 

      Texan lariat

    • C. 

      Hairpin RNA

    • D. 

      Stem and loop DNA

    • E. 

      Splicing intermediate


  • 11. 
    Please put the following steps of Cap synthesis in the correct order. (1) N7 of the capping guanine is methylated (2) The terminal phosphate is removed from the pre-mRNA(3) A capping GMP is added to the pre-mRNA(4) The 2'-O-methyl group of the penultimate nucleotide is methylated
    • A. 

      1,2,3,4

    • B. 

      1,4,3,2

    • C. 

      2,4,1,3

    • D. 

      2,3,1,4

    • E. 

      4,3,2,1


  • 12. 
    Which of the following is NOT a function of the mRNA Cap?
    • A. 

      Protects the mRNA from degradation

    • B. 

      Enhances translatability of the mRNA

    • C. 

      Enhances transport of the mRNA to the cytoplasm

    • D. 

      Enhances splicing of the mRNA

    • E. 

      Helps regulate expression of the mRNA from the promoter


  • 13. 
    Although snRNA U1 fucntions in the nucleus, it receives a 5' Cap to enhances its
    • A. 

      Binding to snRNPs

    • B. 

      Export to the cytoplasm

    • C. 

      Export to the ER lumen

    • D. 

      Export out of the cell

    • E. 

      Binding to the mature mRNA


  • 14. 
    Which of the following is the mRNA polyadenylation signal motif found in mammalian cells?
    • A. 

      AAGAAA

    • B. 

      AAUAAA

    • C. 

      AAUGGG

    • D. 

      UUAUUU

    • E. 

      GGAUUU


  • 15. 
    When does capping of the pre-mRNA occur?
    • A. 

      It is the first nucleotie added by RNA polymerase.

    • B. 

      It occurs before the mRNA reaches a chain length of 30 nt.

    • C. 

      It occurs after the poly (A) tail has been added

    • D. 

      It occurs after splicing has occurred.

    • E. 

      It occurs after export of the mRNA inot the cytoplasm


  • 16. 
    Which of the following is not required for mammalian cell polyadenylation of pre-mRNA?
    • A. 

      PAP

    • B. 

      CPSF

    • C. 

      PABII

    • D. 

      DNA polymerase I

    • E. 

      RNA polymerase II


  • 17. 
    Uncapped mRNA is much more stable than capped mRNA.
    • A. 

      True

    • B. 

      False


  • 18. 
    The 5' cap of mRNA has no effect on the translatability of the mRNA
    • A. 

      True

    • B. 

      False


  • 19. 
    Poly (A) tails are added to the 5' end of the mRNA molecule
    • A. 

      True

    • B. 

      False


  • 20. 
    The additon of poly (A) to mRNA seems to be important for its translatability.
    • A. 

      True

    • B. 

      False


  • 21. 
    RNA polymerase II transcription of a gene usually stops at the polyadenylation site.
    • A. 

      True

    • B. 

      False


  • 22. 
    Pre-mRNA must be cleaved before it is polyadenylated
    • A. 

      True

    • B. 

      False


  • 23. 
    Once a mRNA loses its poly (A) tail, it is imported back into the nucleus
    • A. 

      True

    • B. 

      False


  • 24. 
    Polyadenylation is not required for efficient transport of mRNA out of the nucleus
    • A. 

      True

    • B. 

      False


  • 25. 
    Once the poly (A) tail is added to the mRNA it is very difficult to remove
    • A. 

      True

    • B. 

      False


  • 26. 
    Pre-mRNA processing begins during transcription.
    • A. 

      True

    • B. 

      False


  • 27. 
    Experiment using yeast as a model have shown that cleavage of the poly (A) tail is necessary for transcription termination.
    • A. 

      True

    • B. 

      False


  • 28. 
    The Shine-Dagarno sequence can be found in
    • A. 

      MRNA

    • B. 

      TRNA

    • C. 

      5S rRNA

    • D. 

      16S rRNA

    • E. 

      30S ribosome


  • 29. 
    The Shine-Dalgarno sequence is
    • A. 

      AGGAGGU

    • B. 

      UCCUCCA

    • C. 

      AUGAUGU

    • D. 

      AGGAGGT

    • E. 

      AGGUGGU


  • 30. 
    Put the following steps on prokaryotic translation initiation in the correct order. (1) Binding of IF1, IF2, and GTP to the 30 S subunit (2) Binding of IF3 to the 30S subunit. (3) Binding of the 50S subunit and loss of IF1 and IF3(4) Dissociation of the 70S ribosome. (5) Formation of the 70S initiation complex by dissociation of IF2 and GTP hydrolysis. (6) Formation of the 30S initiantion complex
    • A. 

      4,2,1,6,3,5

    • B. 

      2,1,6,3,5,4

    • C. 

      5,6,3,2,1,4

    • D. 

      1,2,3,4,5,6

    • E. 

      2,4,1,6,3,5


  • 31. 
    Which of the following initiation factors prevents reassociation of the 70s ribosome by binding to the free 30s subunit? 
    • A. 

      IF1

    • B. 

      IF2

    • C. 

      IF3

    • D. 

      IF4

    • E. 

      IF5


  • 32. 
    Which of the following is not part of the 30s initiation complex? 
    • A. 

      IF1, IF2, and IF3

    • B. 

      5S rRNA

    • C. 

      16s rRNA

    • D. 

      Amino-acyl tRNA

    • E. 

      MRNA


  • 33. 
    Match the following eukaryotic translation initiation factors with their correct function?  A. eIF2 B. eIF1 C. eIF3 D. eIF4F E. eIF6 This initiation factor is involved in binding tRNA to the ribosome. 
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E


  • 34. 
    Match the following eukaryotic translation initiation factors with their correct function?  A. eIF2 B. eIF1 C. eIF3 D. eIF4F E. eIF6This initiation factor binds to the 40s subunit and inhibits re-association of the 40s and 60s subunits
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E


  • 35. 
    Match the following eukaryotic translation initiation factors with their correct function?  A. eIF2 B. eIF1 C. eIF3 D. eIF4F E. eIF6This initiation factor is a Cap binding protein.
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E


  • 36. 
    Match the following eukaryotic translation initiation factors with their correct function?  A. eIF2 B. eIF1 C. eIF3 D. eIF4F E. eIF6This initiation factor binds to the 60S subunit and inhibits re-association of the 40S and 60S subunits
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E


  • 37. 
    Match the following eukaryotic translation initiation factors with their correct function?  A. eIF2 B. eIF1 C. eIF3 D. eIF4F E. eIF6This initiation factor aids in ribosome scanning to locate the initiation codon.
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E


  • 38. 
    Which of the following is the best definition of translation?
    • A. 

      A process by which pre-mRNA is transformed inot mature mRNA

    • B. 

      The process by which pre-mRNA is translated y ribozymes to produce proteins

    • C. 

      A process by which a gene is converted into mRNA

    • D. 

      The process by which ribosomes reads the genetic message to produce a protein

    • E. 

      A process by which a tRNA is converted into a protein


  • 39. 
    Which is false?
    • A. 

      In prokaryotes the first amino acid in all mature proteins is an N-formyl-methionine.

    • B. 

      Similar to prokaryotes, eukaryotic translation incorporates a N-formyl-methionine as the first amino acid

    • C. 

      Most eukaryotic mRNAs have 5' caps that function in translation initiation instead of Shine-Dalgarno sequences

    • D. 

      Translation initiation in eukaryotes involves canning of the mRNA to locate a favorable AUG

    • E. 

      Phosphorylation of eukaryotic initiation factors can play both an inhibitory and stimulatory role in translational control of gene expression


  • 40. 
    Which of the following statements is not true concerning the genetic code?
    • A. 

      It is an overlapping code.

    • B. 

      It is a "comma-less" code

    • C. 

      It is an almost univeral code

    • D. 

      It is capable of wobble base pairing

    • E. 

      It is a triplet code


  • 41. 
    Genetic code has all EXCEPT
    • A. 

      Non-overlapping codons

    • B. 

      No gaps

    • C. 

      Absolutely universal code

    • D. 

      Triplets

    • E. 

      Wobbles


  • 42. 
    Direction of translation
    • A. 

      Start from C-terminal

    • B. 

      MRNA is read in the 3' to 5' direction

    • C. 

      Protein is made in C-to-N direction

    • D. 

      Start from both C and N terminal

    • E. 

      Protein is made in the N to C direction, starting from N- terminal


  • 43. 
    EF-Tu is an important protein in cells whose function is to
    • A. 

      Properly fold proteins

    • B. 

      Ensure proper ribosomes assembly

    • C. 

      Escort aminoacyl-tRNA to the ribosome

    • D. 

      Protect rRNA from degradation by RNases

    • E. 

      Stabilize mRNA within the ribosome


  • 44. 
    Please place the steps of translation elongation in the correct order. (1) Peptidyl transferase forms a peptide bond between the peptide in the P site and the newly arrived aminoacyl-tRNA in the A site. (2) EF-G, with GTP, translocates peptidyl-tRNA to the P site (3) Ef-Tu, with GTP, binds an aminoacyl-tRNA to the ribosomal A site
    • A. 

      3,1,2

    • B. 

      3,2,1

    • C. 

      1,2,3

    • D. 

      1,3,2

    • E. 

      2,3,1


  • 45. 
    Termination codons include three nonsense codons
    • A. 

      UAG, UAA, UGA

    • B. 

      UUU, UAU, GAU

    • C. 

      TAG, TAA, TGA

    • D. 

      GAU, AAU, AGU

    • E. 

      GAU, UAA, UGA


  • 46. 
    Which of the following are the three naturally occurring stop codons?
    • A. 

      UAG, UAA, UGG

    • B. 

      UGA, UGG, UAG

    • C. 

      UAA, AUU, GUU

    • D. 

      UAG, UAA, UGA

    • E. 

      UAA, UUA, GGA


  • 47. 
    Which of the following molecules does not resemble a tRNA molecule?
    • A. 

      His-tRNA

    • B. 

      Phe-tRNA

    • C. 

      Puromycin

    • D. 

      Suppressor tRNA

    • E. 

      Ef-Tu


  • 48. 
    Misfolded proteins can be toxic to cells and lead to serious dieases in humans. Which of the following diseases is caused by a misfolded protein?
    • A. 

      Sickle cell anemia

    • B. 

      Bovine spongiform encephalitis

    • C. 

      Diabetes

    • D. 

      Burketts Lymphoma

    • E. 

      HIV-AIDS


  • 49. 
    Which is false?
    • A. 

      Peptidyl transferase activity can be inhibited in bacteria by chloramphenicial

    • B. 

      Wobble base pairing can occur between tRNA and the third base in the mRNA codon

    • C. 

      A trasversion is a mutation in the genetic code that changes a purine to a pyrimidine

    • D. 

      Peptidyl transferase activity can be inhibited in prokaryotic cells by penicillin

    • E. 

      Mitochondrial mRNAs carry codons that don't conform to the unviersal genetic code.


  • 50. 
    Which of the following enzymes is used to search for CpG islands? 
    • A. 

      Uracil-N-glycosylase

    • B. 

      Lysozyme

    • C. 

      The restriction enzymes that cut only unmethylated CCGG

    • D. 

      The restriction enzymes that cut methylated CCGG.

    • E. 

      The restriction enzymes that cut both methylated and unemthylated CCGG.


  • 51. 
    How were the genetic markers that are linked to Huntington disease genes screened originally? 
    • A. 

      By exon trapping

    • B. 

      By RFLPs

    • C. 

      By genome sequencing

    • D. 

      By S1 mapping

    • E. 

      By DNase mapping


  • 52. 
    Regarding to identifying the gene for Huntington disease (HD), which is not correct? 
    • A. 

      The HD gene is located in chromosome 4

    • B. 

      It is identified with the Exon trap

    • C. 

      The mutation: a CAG repeat increases its copies, leading to extra glutamines inserted into huntingtin

    • D. 

      The HD genes is actually bacterial gene

    • E. 

      The HD gene is mapped with positional cloning


  • 53. 
    How were Huntington disease genes identified? 
    • A. 

      By exon trapping

    • B. 

      By RFLPs

    • C. 

      By genome sequencing

    • D. 

      By S1 mapping

    • E. 

      By DNase mapping


  • 54. 
    Which of the following processes was used to locate the gene responsible for Huntington disease? 
    • A. 

      Shot-gun cloning

    • B. 

      Positional cloning

    • C. 

      Genome sequencing

    • D. 

      2D gel

    • E. 

      Proteomics


  • 55. 
    With respect to human genome project, which approach is wrong to take? 
    • A. 

      Vector for large-scale genome projects

    • B. 

      The clone-by clone strategy

    • C. 

      Shotgun

    • D. 

      Sequencing standards

    • E. 

      Linker insertion to map replication origins


  • 56. 
    Which of the following was the first free living organism to have its genome sequenced? 
    • A. 

      Herpes simplex virus

    • B. 

      (gamma) X174

    • C. 

      Haemophilus infuenzae Rd

    • D. 

      Methanococcus jannaschii

    • E. 

      Saccharomyces cerevisiae


  • 57. 
    Which of the following free living organisms has the smallest genome, containing about only 470 genes? 
    • A. 

      Haemophilus influenzae Rd

    • B. 

      Mycoplasma genitalium

    • C. 

      Methanococcus jannaschii

    • D. 

      Saccharomyces cerevisiae

    • E. 

      Caenorhabditis elegans


  • 58. 
    Which is not correct about annotated genes? 
    • A. 

      Known genes: Their sequence are identical to known human genes

    • B. 

      Related genes: Their sequences are homologous to known human genes

    • C. 

      Predicted genes that contain sequences are homologous to EST (expressed sequences tags).

    • D. 

      Pseudogenes have trouble to express

    • E. 

      Pseudogenes are exons that direct translation


  • 59. 
    Which is wrong? 
    • A. 

      Paralogs: the gene for Huntington disease has a paralog in bacteria

    • B. 

      Orthologs: homologous genes in different species

    • C. 

      Paralogs: homologous genes in a species

    • D. 

      Homologs: homologous genes

    • E. 

      Homologs: can be orthologs for paralogs


  • 60. 
    Which of the following is not a finding from analysis of the complete DNA sequence of human chromosome 22? 
    • A. 

      It contains 679 annotated genes

    • B. 

      It contains local and long range duplications

    • C. 

      It contains orthologs to the mouse chromosome

    • D. 

      It contains very little noncoding DNA

    • E. 

      It contains "poison regions" or gaps that may never get sequenced


  • 61. 
    The estimated total number of genes in the human genome is 
    • A. 

      10,000-15,000

    • B. 

      20,000-25,000

    • C. 

      40,000-50,000

    • D. 

      50,000-75,000

    • E. 

      100,000-130,000


  • 62. 
    DNA microarrays can be used to study 
    • A. 

      The clustering of expression of genes i time and space

    • B. 

      The DNA sequence of multiple chromosomes

    • C. 

      The DNA sequence of multiple genomes

    • D. 

      Chromosomal rearrangements

    • E. 

      Chromosomal abnormalities


  • 63. 
    Which of the following are techniques used for genomic functional profiling? 
    • A. 

      DNA microchips

    • B. 

      RNAi analysis

    • C. 

      Deletion analysis

    • D. 

      RNAi analysis and Deletion analysis

    • E. 

      RFLP


  • 64. 
    Why proteomics is useful? Because of 
    • A. 

      About 50% or more of polyadenylated RNAs that do not encode protiens, and noncoding RNAs (ncRNA), or transcripts of unknown functions (TUFs).

    • B. 

      Splicing of a transcript that may encode several proteins

    • C. 

      Degradation of mRNAs

    • D. 

      Post-translational modifications

    • E. 

      All likely


  • 65. 
    Bioinformatics databases include all EXCEPT 
    • A. 

      GenBank

    • B. 

      BOA

    • C. 

      EMBL

    • D. 

      Swissprot

    • E. 

      TIGR


  • 66. 
    Genomic sequence information can be applied to study which of the following? 
    • A. 

      Evolution of genomes

    • B. 

      Function of genomes

    • C. 

      Structure of genomes

    • D. 

      Proteomics

    • E. 

      All of the choices are correct


Back to top

Removing ad is a premium feature

Upgrade and get a lot more done!
Take Another Quiz
We have sent an email with your new password.