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 noenveloped viruses
Which of the following is NOT used as a criterion to classify viruses?
Which of the following is NOT utilized to culture viruses?
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps?
The definition of lysogeny is
phage DNA is incorporated into the 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?
The structures illustrated in figure 13.1 are composed of
A clear area against a confluent “lawn” of bacteria is called a
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?
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
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 templete
An infectious protein is a
An envelope is acquired during which of the following steps?
Which of the following statements is NOT true of lysogeny?
its causes lysis of host cells
An example of a latent viral infection is
A virus’s ability to infect an animal cell depends primarily upon the
presence of receptor sites on the cell membrance
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?
The mechanism whereby an enveloped virus leaves a host cell is called
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
Bacteriophage replication differs from animal virus replication because only bacteriophage replication involes
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
Which of the following places these items in the correct order for DNA-virus replication?
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 RNA template will be incorporated into the virus capsid of
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
Same viruses, such as human herpesvirus 1, infect a cell without causing symptoms, These are called
The following steps occur during multiplication of retroviruses. Which is the fourth step?
synthesis of double-stranded DNA
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?
Most RNA viruses carry which of the following enzymes?
RNA-dependent RNA polymerase
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