Cell Bio - Chapter 13 (Book Questions)

23 Questions | Total Attempts: 129

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Cell Bio - Chapter 13 (Book Questions)

Questions and Answers
  • 1. 
    Which of following illustrates negative control?
    • A. 

      A repressor that becomes active when bound to a corepressor and inhibits transcription.

    • B. 

      A gene that binds a repressor and becomes active.

    • C. 

      An activator that becomes active when bound to a coactivator and activates transcription.

    • D. 

      A repressor that binds a gene and becomes inactive.

  • 2. 
    In regulation of the lac operon, when lactose is present and glucose is absent
    • A. 

      The repressor is able to bind to the operator.

    • B. 

      The repressor is unable to bind to the operator.

    • C. 

      Transcription of structural genes occurs.

    • D. 

      Transcription of lactose occurs.

    • E. 

      Both b and c are correct.

  • 3. 
    In regulation of the trp operon, when tryptophan is present,
    • A. 

      The repressor is able to bind to the operator.

    • B. 

      The repressor is unable to bind to the operator.

    • C. 

      Transcription of the repressor is inhibited.

    • D. 

      Transcription of the structural genes, operator, and promoter occurs.

  • 4. 
    In common operon models, the function of the promoter is to
    • A. 

      Code for the repressor protein.

    • B. 

      Bind with RNA polymerase.

    • C. 

      Bind to the repressor.

    • D. 

      Code for the regulator gene.

  • 5. 
    Which of the following statements is/are true regarding operons?
    • A. 

      The regulator gene is transcribed with the structural genes.

    • B. 

      The structural genes are always transcribed.

    • C. 

      All genes are always transcribed.

    • D. 

      The regulator gene has its own promoter.

  • 6. 
    Which of the following regulate gene expression in the eukaryotic nucleus?
    • A. 

      Posttranslational control

    • B. 

      Transcriptional control

    • C. 

      Posttranscriptional control

    • D. 

      Translational control

    • E. 

      Both b and c are correct.

  • 7. 
    Which of the following mechanisms may create multiple mRNAs from the same gene?
    • A. 

      Posttranslational control

    • B. 

      Alternative mRNA splicing

    • C. 

      Binding of a transcription factor

    • D. 

      Chromatin remodeling

    • E. 

      MiRNAs

  • 8. 
    Translational control of gene expression occurs within the
    • A. 

      Nucleus

    • B. 

      Cytoplasm

    • C. 

      Nucleolus

    • D. 

      Mitochondria

  • 9. 
    Alternative mRNA splicing is an example of which type of regulation of gene expression?
    • A. 

      Transcriptional

    • B. 

      Posttranscriptional

    • C. 

      Translational

    • D. 

      Posttranslational

  • 10. 
    A scientist adds radioactive uridine (label for RNA) to a culture of cells and examines an autoradiograph. Which type of chromatin is apt to show the label?
    • A. 

      Heterochromatin

    • B. 

      Euchromatin

    • C. 

      The histones, not the DNA

    • D. 

      The DNA, not the histones

    • E. 

      Both a and D are correct

  • 11. 
    Barr bodies are
    • A. 

      Genetically active X chromosomes in males.

    • B. 

      Genetically inactive X chromosomes in females.

    • C. 

      Genetically active Y chromosomes in males.

    • D. 

      Genetically inactive Y chromosomes in females.

  • 12. 
    Which of these might cause a proto-oncogene to become an oncogene?
    • A. 

      Exposure of the cell to radiation

    • B. 

      Exposure of the cell to certain chemicals

    • C. 

      Viral infection of the cell

    • D. 

      Exposure of the cell to pollutants

    • E. 

      All of these are correct

  • 13. 
    A cell is cancerous. You might find an abnormality in
    • A. 

      A proto-oncogene.

    • B. 

      A tumor suppressor gene.

    • C. 

      Regulation of the cell cycle.

    • D. 

      Tumor cells.

    • E. 

      All of these are correct.

  • 14. 
    A tumor suppressor gene
    • A. 

      Inhibits cell division

    • B. 

      Opposes oncogenes

    • C. 

      Prevents cancer

    • D. 

      Is subject to mutations

    • E. 

      All of these are correct

  • 15. 
    What is the structure labeled A?
  • 16. 
    What is the structure labeled B?
  • 17. 
    What is the structure labeled C?
  • 18. 
    What is the structure labeled D?
  • 19. 
    What is the structure labeled E?
  • 20. 
    If the DNA codons are CAT CAT CAT, and a guanine base is added at the beginning, which would result?
    • A. 

      CAT CAT CAT G

    • B. 

      G CAT CAT CAT

    • C. 

      GCA TCA TCA T

    • D. 

      GC ATC ATC AT

  • 21. 
    A mutation in a DNA molecule involving the replacement of one nucleotide base pair with another is called a(n)
    • A. 

      Frameshift mutation.

    • B. 

      Transposon.

    • C. 

      Deletion mutation.

    • D. 

      Point mutation.

    • E. 

      Insertion mutation.

  • 22. 
    Which of these is characteristic of cancer?
    • A. 

      It may involve a lack of mutations over a length of time.

    • B. 

      It cannot be tied to particular environmental factors.

    • C. 

      Apoptosis is one of the first developmental effects.

    • D. 

      Mutations in certain types of genes.

    • E. 

      It typically develops within a short period of time.

  • 23. 
    Which is not evidence that eukaryotes control transcription?
    • A. 

      Euchromatin/heterochromatin

    • B. 

      Existence of transcription factors

    • C. 

      Lampbrush chromosomes

    • D. 

      Occurrence of mutations

    • E. 

      All of these are correct.