chapter 13
How do all viruses differ from bacteria?
Viruses are not composed of cells
Which of the following statements provides the most significant support for the idea that viruses are nonliving chemicals?
They cannot reproduce themselves outside a host.
Which of the following statements about viral spikes is FALSE?
They are found only on nonenveloped viruses.
Which of the following is NOT used as a criterion to classify viruses?
biochemical tests
Which of the following is NOT utilized to culture viruses?
culture media
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps
biosynthesis
The definition of lysogeny is
phage DNA is incorporated into host cell DNA
A viroid is a(n)
infectious piece of RNA without a capsid.
In Figure 13.1, which structure is a complex virus
b
The structures illustrated in Figure 13.1 are composed of
Capsomeres
A clear area against a confluent lawn of bacteria is called a
plaque
Continuous cell lines differ from primary cell lines in that
continuous cell lines can be maintained through an indefinite number of generations.
Which of the following is necessary for replication of a prion?
PrPSc
14) A persistent infection is one in which
the disease process occurs gradually over a long period
Which of the following statements is FALSE?
The prophage makes the host cell immune to infection by other phages.
Lysogeny can result in all of the following EXCEPT
immunity to reinfection by any phage
Which of the following would be the first step in biosynthesis of a virus with a (minus) strand of RNA?
synthesis of double-stranded RNA from an RNA template
An infectious protein is a
prion
An envelope is acquired during which of the following steps?
release
Which of the following statements is NOT true of lysogeny?
It causes lysis of host cells.
An example of a latent viral infection is
cold sores
A viruss ability to infect an animal cell depends primarily upon the
presence of receptor sites on the cell membrane
Assume you have isolated an unknown virus. This virus has a single, positive sense strand of RNA, and possesses an envelope. To which group does it most likely belong
togavirus
The mechanism whereby an enveloped virus leaves a host cell is called
budding
The most conclusive evidence that viruses cause cancers is provided by
cancer following injection of cell-free filtrates
Bacteriophages derive all of the following from the host cell EXCEPT
lysozyme
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves
injection of naked nucleic acid into the host cell
Generally, in an infection caused by a DNA-containing virus, the host animal cell supplies all of the following EXCEPT
DNA polymerase.
Which of the following places these items in the correct order for DNA-virus replication?
1. Maturation
2. DNA synthesis
3. Transcription
4. Translation
2; 3; 4; 1
A viral species is a group of viruses that
has the same genetic information and ecological niche.
Viruses that utilize reverse transcriptase belong to the virus families
Hepadnaviridae and Retroviridae
DNA made from an RNA template will be incorporated into the virus capsid of
Hepadnaviridae
Which of the following statements about viruses is FALSE?
Viruses use their own catabolic enzymes.
A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?
The virus is causing the death of the infected cells in the patient.
Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called
latent viruses
Assume a patient had chickenpox (human herpesvirus 3) as a child. Which line on the graph in Figure 13.2 would show the number of viruses present in this person as a 60-year-old with shingles (human herpesvirus 3)?
e
Assume a patient has influenza. During which time on the graph in Figure 13.2 would the patient show the symptoms of the illness
c
The following steps occur during multiplication of herpesviruses. Which is the third step?
uncoating
The following steps occur during multiplication of retroviruses. Which is the fourth step?
synthesis of double-stranded DNA
Oncogenic viruses
cause tumors to develop
Which one of the following steps does NOT occur during multiplication of a picornavirus?
synthesis of DNA
Which of the following is most likely a product of an early gene?
DNA polymerase
Most RNA viruses carry which of the following enzymes
Most RNA viruses carry which of the following enzymes
The following steps occur during biosynthesis of a + strand RNA virus. What is the third step
synthesis of strand RNA
What contributes to antigenic shift in influenza viruses?
a segmented genome