Viruses, Transposable Elements, and Cancer Practice Problems

By — McGraw-Hill Professional
Updated on Aug 23, 2011

Review the following concepts if needed:


Vocabulary   For each of the following definitions, give the appropriate term and spell it correctly. Terms are single words unless indicated otherwise.

  1. The protein coat of a virus.
  2. The name for all viruses that infect bacterial cells.
  3. The inability of some bacteriophage to replicate in certain hosts. (Two words.)
  4. The type of viral life cycle characterized by plaque production.
  5. Phage DNA integrated into a bacterial genome.
  6. Portion of a host-cell membrane that is acquired by a eukaryotic virus as it leaves the cell.
  7. An adjective descriptive of the type of viral infection wherein virions are slowly released from the cell without lysing or killing the host cell.
  8. The class of RNA viruses that produce cDNA as part of their life cycle.
  9. Mobile DNA elements.
  10. Cancer-causing genes.

Multiple Choice Questions   Choose the one best answer.

  1. Which of the following is not characteristic of eukaryotic viruses?     (a)  only one kind of nucleic acid per virion     (b)  inhibited by antibiotics     (c)  replicate independently of cells     (d)  pass through bacterial filters     (e)  more than one of the above
  2. Lambda phage can transduce bacterial genes only at or near the gene concerned with     (a)  repressor synthesis     (b)  immunity repressor     (c)  CAP     (d)  lactose fermentation     (e)  galactose fermentation
  3. Viruses generally only infect one or a few particular species. This is called     (a)  host restriction     (b)  host range     (c)  cell specificity     (d)  viral range     (e)  host modification
  4. Restriction-modification systems of bacteria exist to     (a)  protect bacteria from invading foreign DNA     (b)  promote conjugation     (c)  help the bacterial chromosome replicate     (d)  encourage recombination of new genetic material (e) promote complementation
  5. A prophage is involved in     (a)  lytic cycle     (b)  oncogenesis     (c)  transposition     (d)  lysogeny     (e)  plaque formation
  6. Specialized transduction is best characterized by     (a)  the transfer of a specific naked DNA sequence into a recipient cell     (b)  the transfer of an F plasmid to a recipient cell     (c)  the transfer of a particular region of the bacterial chromosome to a recipient cell via a phage vector     (d)  the transfer of a specific gene sequence through a sex pilus     (e)  the induction of oncogenesis
  7. Which of the following enzymes is required for most transposition events:     (a)  DNA polymerase     (b)  telomerase     (c)  transposase     (d)  reverse transcriptase     (e)  RNA polymerase
  8. Among all known phages reproducing vegetatively, the only one that neither kills nor lyses its host cell is     (a)  M13     (b)  T4     (c)  Mu     (d)  P1     (e) X174
  9. Cells that have been transformed into tumor cells exhibit the following characteristic(s).     (a)  If cells are transformed by an oncogenic virus, the virus must be integrated into host DNA.     (b)  They do not require surface contact to grow in cell culture.     (c)  They may form tumors when injected into an animal of the same species from which they were derived.     (d)  Their chromosome number often exceeds the normal diploid number.     (e)  All of the above are characteristics of transformed cells
  10. Which of the following statements regarding oncogenic retroviruses is incorrect?     (a)  They can generate tumors in at least some species in which they can cause a productive infection.     (b)  Infective retroviruses acquire an envelope of host membrane as they exit the cell.     (c)  Integration of viral DNA into host DNA is obligatory for the production of progeny viruses.     (d)  All oncogenes of these viruses are nonessential for the production of progeny virions.     (e)  All genes of the proretrovirus are silenced except for the one responsible for repression of lytic functions.



  1. capsid
  2. bacteriophage or phage
  3. host restriction
  4. lytic
  5. prophage
  6. envelope
  7. persistent
  8. retroviruses
  9. transposons
  10. oncogenes

Multiple Choice

  1. e (b, c)
  2. e
  3. b
  4. a
  5. d
  6. c
  7. c
  8. a
  9. e
  10. e
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