Which of the following statements provides the most significant support for the idea that viruses are nonliving chemicals?
They cannot reproduce themselves
Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps?
Continuous cell lines differ from primary cell lines in that
Continuous cell lines can be maintained through an indefinite number of generations
A persistent infection is an infection in which
The disease process occurs gradually over a long period
Which of the following statements is false?
A. A prophage is phage DNA inserted into a bacterial chromosome
B. A prophage can pop out of the chromosome
C. Prophage genes are represented by a repressor protein coded for by the prophage
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
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 - strand of RNA
Synthesis of double-stranded RNA from an RNA template
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
All of the above
Assume you have isolated an unknown virus. It is a single-stranded RNA, enveloped virus. To which group does it most likely belong?
To which group does a small, nonenveloped single-stranded RNA virus most likely belong?
The most conclusive evidence that viruses can cause cancers is provided by
Cancer following injection of cell-free filtrates
Generalized transduction differs from specialized transduction in that generalized transduction
Transfers specific DNA
Generally, in a DNA-containing virus infection, the host animal cell supplies all of the following EXCEPT
Put the following in the correct order for DNA-virus replication
DNA synthesis, Transcription, Translation, Maturation
Viruses that have reverse transcriptase are in the
Hepadnaviridae and Retroviridae
(Hepatitis and HIV)
Which of the following statements about viruses is false?
A. Viruses contain DNA or RNA but never both
B. Viruses contain a protein coat
C. Viruses use the anabolic machinery of the cell
D. Viruses use their own catabolic enzymes
E. Viruses have genes
Viruses use their own catabolic enzymes
Some viruses, such as human herpesvirus 1, infect a cell without causeing symptoms; these are called
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)?
Assume a patient has influenza. During which time (on the graph in Figure 13.2) would the patient show the symptoms of the illness?
The following steps occur during multiplication of retroviruses. What it the fourth step?
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
Which of the following steps does NOT occur during multiplication of a picornavirus (single stranded RNA)?
Synthesis of DNA
The following steps occur during biosynthesis of a + strand RNA virus. What is the third step?
Synthesis of a - strand RNA