Molecular Biology Exam #3

50 Questions | Total Attempts: 284

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Molecular Biology Quizzes & Trivia

Third Exam!


Questions and Answers
  • 1. 
    Please put the following steps of RNA 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. 

      2,3,1,4

    • C. 

      1,4,3,2

    • D. 

      2,4,1,3

    • E. 

      4,3,2,1

  • 2. 
    When does capping of the pre-mRNA occur? 
    • A. 

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

    • B. 

      It is the first nucleotide added by the RNA polymerase

    • C. 

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

    • D. 

      It occurs after splicing has occurred

    • E. 

      It occurs after export of the mRNA into the cytoplasm

  • 3. 
    • A. 

      The gene contains no introns

    • B. 

      The gene contains one intron

    • C. 

      The gene contains two introns.

    • D. 

      The gene contains three intron

    • E. 

      The results are inconclusive

  • 4. 
    Which of the following experiments was useful in determining the existence of introns in the adenovirus genome? 
    • A. 

      DNA/DNA hybridization

    • B. 

      RNA/RNA hybridization

    • C. 

      RT-PCR

    • D. 

      R-looping experiments

    • E. 

      CDNA cloning experiments

  • 5. 
    The first two bases and the last two bases in the splicing signal consensus sequences are 
    • A. 

      GT-AG

    • B. 

      GT-TG

    • C. 

      CU-AG

    • D. 

      GU-AC

    • E. 

      GU-AG

  • 6. 
    Which of the following is the name for the yeast 40S particle where mRNA splicing takes place? 
    • A. 

      Ribosome

    • B. 

      Nucleolus

    • C. 

      HnRNA

    • D. 

      Spliceosome

    • E. 

      R-loop

  • 7. 
    "Snurps" or snRNPs are composed of 
    • A. 

      RNA

    • B. 

      RNA and protein

    • C. 

      DNA

    • D. 

      Protein

    • E. 

      DNA and RNA

  • 8. 
    Bioinformatics databases include all EXCEPT 
    • A. 

      Swiss data bank

    • B. 

      GenBank

    • C. 

      EMBL

    • D. 

      Swissprot

    • E. 

      TIGR

  • 9. 
    DNA microarrays can be used to study
    • A. 

      The DNA sequence of multiple chromosomes

    • B. 

      The clustering of expression of genes in time and space

    • C. 

      The DNA sequence of multiple genomes

    • D. 

      Chromosomal rearrangements

    • E. 

      Chromosomal abnormalities

  • 10. 
    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

  • 11. 
    The catalytic center of the spliceosome appears to include 
    • A. 

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

    • 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+

  • 12. 
    • A. 

      U1: base pairs with 5' splice site of mRNA

    • B. 

      U2: base pairs with the 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.

  • 13. 
    Spliceosomal lariat is 
    • A. 

      Cowboy's lasso

    • B. 

      Texan lariat

    • C. 

      Hairpin RNA

    • D. 

      Splicing intermediate

    • E. 

      Stem and loop DNA

  • 14. 
    Which of the followign is NOT a function of the mRNA Cap? 
    • A. 

      It protects the mRNA from degradation

    • B. 

      It enhances translatability of the mRNA

    • C. 

      It helps regulate expression of the mRNA from the promoter

    • D. 

      It enhances splicing of the mRNA

    • E. 

      It enhances transport of the mRNA to the cytoplasm

  • 15. 
    Although snRNA U1 functions in the nucleus, it receives a 5' Cap to enhance its 
    • A. 

      Export to the cytoplasm

    • B. 

      Binding to snRNPs

    • C. 

      Export too the ER lumen

    • D. 

      Export out of the cell

    • E. 

      Binding to the mature mRNA

  • 16. 
    Which of the following is the mRNA polyadenylation signal motif found in mammalian cells? 
    • A. 

      AAGAAA

    • B. 

      AAUGGG

    • C. 

      AAUAAA

    • D. 

      UUAUUU

    • E. 

      GGAUUU

  • 17. 
    Which of the following was the first free living organism to have its genome sequenced? 
    • A. 

      Herpes simplex virus

    • B. 

      Haemophilus influenzae Rd

    • C. 

      Beta X174

    • D. 

      Methanococcus jannaschii

    • E. 

      Saccharomyces cerevisiae

  • 18. 
    Which of the following free living organisms have the smallest genome, containing about only 470 genes? 
    • A. 

      Mycoplasma genitalium

    • B. 

      Haemophilus influenzae Rd

    • C. 

      Methanococcus jannaschii

    • D. 

      Saccharomyces cerevisiae

    • E. 

      Caenorhabditis elegans

  • 19. 
    Which is not correct about annotated genes? 
    • A. 

      Known genes: their sequences 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 sequence tags)

    • D. 

      Pseudogenes are exons that direct translation

    • E. 

      Pseudogenes have trouble to express

  • 20. 
    Which of the following is not required for mammalian cell polyadenylation of pre-mRNA? 
    • A. 

      PAP

    • B. 

      CPSF

    • C. 

      DNA polymerase I

    • D. 

      PABII

    • E. 

      RNA polymerase II

  • 21. 
    The Shine-Dalgarno sequence can be found in 
    • A. 

      TRNAa

    • B. 

      MRNA

    • C. 

      5S rRNA

    • D. 

      16S rRNA

    • E. 

      30S ribosome

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

      It contains very little noncoding DNA

    • B. 

      It contains local and long range duplications

    • C. 

      It contains orthologs to the mouse chromosome

    • D. 

      It contains 679 annotated genes

    • E. 

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

  • 23. 
    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

  • 24. 
    The shine-Dalgarno sequence is 
    • A. 

      UCCUCCA

    • B. 

      AGGAGGU

    • C. 

      AUGAUGU

    • D. 

      AGGAGGT

    • E. 

      AGGUGGU

  • 25. 
    Put the followign steps of prokaryotic translation initiation in the correct order (1) Binding of IF1, IF2, and GTP to the 30s 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 initiation complex 
    • A. 

      2,4,1,6,3,5

    • B. 

      2,1,6,3,5,4

    • C. 

      5,6,3,2,1,4

    • D. 

      1,2,3,4,5,6

    • E. 

      4,2,1,6,3,5