Ch 13 Micro

1) In which of the following ways do viruses differ from bacteria?
A) Viruses are filterable.
B) Viruses don't have any nucleic acid.
C) Viruses are obligate intracellular parasites.
D) Viruses don't reproduce.
E) Viruses are not composed of cells.

Which of the following statements provides the most significant support for the idea that viruses are nonliving chemicals?
A) They cannot reproduce themselves outside a host.
B) They cause diseases similar to those caused by chemicals.
C) They are not composed of cells.
D) They are chemically simple.
E) They are filterable.

Which of the following statements about spikes is false?
A) They are used for absorption.
B) They are found only on enveloped viruses.
C) They are used for penetration.
D) They are found only on nonenveloped viruses.
E) They may cause hemagglutination.

Which of the following is NOT used as a criterion to classify viruses?
A) Morphology
B) Nucleic acid
C) Biochemical tests
D) Size
E) Number of capsomeres

Which of the following is NOT a method of culturing viruses?
A) In laboratory animals
B) In culture media
C) In embryonated eggs
D) In cell culture
E) None of the above

Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps?

A) Biosynthesis
B) Penetration
C) Uncoating
D) Release
E) Adsorption

 The definition of lysogeny is
A) When the burst time takes an unusually long time.
B) Phage DNA is incorporated into host cell DNA.
C) Lysis of the host cell due to a phage.
D) The period during replication when virions are not present.
E) Attachment of a phage to a cell.

A viroid is
A) An infectious protein.
B) A capsid without a nucleic acid.
C) A complete, infectious virus particle.
D) A nonenveloped, infectious piece of RNA.
E) A provirus.

A clear area against a confluent "lawn" of bacteria is called a
A) Cell lysis.
B) Pock.
C) Plaque.
D) Phage.
E) Rash

Continuous cell lines differ from primary cell lines in that
A) Continuous cell lines are derived from primary cell lines.
B) Continuous cell lines always have to be reisolated from animal tissues.
C) Continuous cell lines are from human embryos.
D) Viruses can be grown in continuous cell lines.
E) Continuous cell lines can be maintained through an indefinite number of generations.

Which of the following is necessary for replication of a prion?
A) DNA polymerase
B) PSc
C) Lysozyme
D) RNA
E) DNA

A persistent infection is an infection in which
A) The virus remains in equilibrium with the host without causing a disease.
B) Host cells are gradually lysed.
C) The disease process occurs gradually over a long period.
D) Viral replication is unusually slow.
E) Host cells are transformed.

Which of the following statements is false?
A) A prophage can pop out of the chromosome.
B) Prophage genes are represented by a repressor protein coded for by the prophage.
C) A prophage is phage DNA inserted into a bacterial chromosome.
D) A prophage may result in new properties of the host cell.
E) The prophage makes the host cell immune to infection by other phages.

Lysogeny can result in all of the following EXCEPT
A) Immunity to reinfection by the same phage.
B) Acquisition of new characteristics by the host cell.
C) Immunity to reinfection by any phage.
D) Transduction of specific genes.
E) None of the above

Which of the following would be the first step in biosynthesis of a virus with a - strand of RNA?
A) Synthesis of DNA from a DNA template
B) Synthesis of DNA from an RNA template
C) Transcription of mRNA from DNA
D) Synthesis of double-stranded RNA from a DNA template
E) Synthesis of double-stranded RNA from an RNA template

An infectious protein is a
A) Prion.
B) Papovavirus.
C) Bacteriophage.
D) Viroid.
E) Retrovirus.

An envelope is acquired during which of the following steps?
A) Release
B) Biosynthesis
C) Adsorption
D) Penetration
E) Uncoating

Which of the following contributes to the difficulty in establishing the etiology of cancer?
A) Most viral particles can infect cells without inducing cancer.
B) Cancer may not develop until long after infection.
C) Cancers do not seem to be contagious.
D) Viruses are difficult to observe.
E) All of the above.

An example of a latent viral infection is
A) Cold sores.
B) Subacute sclerosing panencephalitis.
C) Influenza.
D) Smallpox.
E) Mumps.

The most common route of accidental AIDS transmission to health care workers is
A) Fecal–oral.
B) Aerosol.
C) Mouth to mouth.
D) Environmental surface contact.
E) Needlestick.

Assume you have isolated an unknown virus. It is a single-stranded RNA, enveloped virus. To which group does it most likely belong?
A) Papovavirus
B) Picornavirus
C) Togavirus
D) Retrovirus
E) Herpesvirus

To which group does a small, nonenveloped single-stranded RNA virus most likely belong?
A) Picornavirus
B) Herpesvirus
C) Retrovirus
D) Papovavirus
E) Togavirus

The most conclusive evidence that viruses cause cancers is provided by
A) The presence of antibodies against viruses in cancer patients.
B) Some liver cancer patients having had hepatitis.
C) Treating cancer with antibodies.
D) Cancer following injection of cell-free filtrates.
E) Finding oncogenes in viruses.

Bacteriophages derive all of the following from the host cell EXCEPT
A) Amino acids.
B) Nucleotides.
C) Lysozyme.
D) tRNA.
E) A.T.P.

Generalized transduction differs from specialized transduction in that generalized transduction
A) Involves lysogeny.
B) Transfers DNA from one cell to another.
C) Kills the host.
D) Transfers specific DNA.
E) Lyses the host cell.

Generally, in a DNA-containing virus infection, the host animal cell supplies all of the following EXCEPT
A) RNA polymerase.
B) Nucleotides.
C) DNA polymerase.
D) tRNA.
E) All of the above are supplied by the host animal cell

Put the following in the correct order for DNA-virus replication: 1-Maturation;  2-DNA synthesis;  3-Transcription;  4-Translation.
A) 2, 3, 4, 1
B) 1, 2, 3, 4
C) 4, 3, 2, 1
D) 4, 1, 2, 3
E) 3, 4, 1, 2

A viral species is a group of viruses that
A) Have the same morphology and nucleic acid.
B) Can't be defined.
C) Infect the same cells and cause the same disease.
D) Have the same genetic information and ecological niche.

Viruses that have reverse transcriptase are in the
A) Retroviridae and Picornaviridae.
B) Hepadnaviridae and Retroviridae.
C) Herpesviridae and Retroviridae.
D) Influenzavirus.
E) Bacteriophage families.

DNA made from an RNA template will be incorporated into the virus capsid of
A) Bacteriophage families.
B) Hepadnaviridae.
C) Herpesviridae.
D) Retroviridae.
E) Influenzavirus.

Which of the following statements about viruses is false?
A) Viruses use the anabolic machinery of the cell.
B) Viruses contain a protein coat.
C) Viruses contain DNA or RNA but never both.
D) Viruses have genes.
E) Viruses use their own catabolic enzymes.

 Approximately how many virus particles could fit along a 1-millimeter line?
A) 20
B) 20,000
C) 2
D) 2,000,000
E) 200

Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms; these are called
A) Unconventional viruses.
B) Phages.
C) Latent viruses.
D) Lytic viruses.
E) Slow viruses.

The following steps occur during multiplication of herpesviruses. What is the third step?
A) Uncoating
B) Release
C) Attachment
D) Penetration
E) Biosynthesis

The following steps occur during multiplication of retroviruses. What is the fourth step?
A) Penetration
B) Synthesis of + RNA
C) Uncoating
D) Attachment
E) Synthesis of double-stranded DNA

Nontoxic strains of Vibrio cholerae can become toxic when they are in the human intestine with toxic strains of bacteria. This suggests that the toxin genes are acquired by
A) Host enzymes.
B) Prions.
C) Reverse transcriptase.
D) Transduction.
E) None of the above.

Which one of the following steps does NOT occur during multiplication of a picornavirus?
A) Synthesis of + strands of RNA
B) Synthesis of - strands of RNA
C) Synthesis of viral proteins
D) Synthesis of DNA
E) None of the above

Which of the following is most likely a product of an early gene? 
A) Capsid proteins
B) DNA polymerase
C) Envelope proteins
D) Lysozyme
E) Spike proteins

Most RNA viruses carry which of the following enzymes?
A) Lysozyme
B) ATP synthase
C) RNA-dependent RNA polymerase
D) DNA-dependent DNA polymerase
E) Reverse transcriptase

The following steps occur during biosynthesis of a + strand RNA virus. What is the third step?
A) Synthesis of viral proteins
B) Synthesis of - strand RNA
C) Attachment
D) Penetration and uncoating
E) Synthesis of + strand RNA

What contributes to antigenic shift in influenza viruses?
A) Different subtypes
B) Segmented genome
C) Worldwide distribution
D) Ease of transmission
E) Attachment spikes