BIOL 1107 Quiz 14 Chapter 17 Practice

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have A. T2 protein and T4 DNA. B. T4 protein and T2 DNA. C. T2 protein and T2 DNA. D. T4 protein and T4 DNA.

D. T4 protein and T4 DNA.

Emerging viruses arise by A. mutation of existing viruses. B. the spread of existing viruses to new host species. C. the spread of existing viruses more widely within their host species. D. all of the above.

D. all of the above.

Which of the three types of viruses shown in Figure 17.1 would you expect to include a capsid(s)? A. I only B. II only C. I and II only D. all three

D. all three

What are prions? A. mobile segments of DNA B. tiny molecules of RNA that infect plants C. viral DNA that has had to attach itself to the host genome D. misfolded versions of normal brain protein E. viruses that invade bacteria

D. misfolded versions of normal brain protein

Which of the following responses correctly lists the order of events in a generalized viral replicative cycle? A. The virus enters the cell, host enzymes replicate the viral genome, enzymes transcribe the viral genome into mRNA B. Host enzymes replicate the viral genome, the virus enters the cell, enzymes transcribe the viral genome into mRNA C. The virus enters the cell, enzymes transcribe the viral genome into mRNA, host enzymes replicate the viral genome D. Enzymes transcribe the viral genome into mRNA, host enzymes replicate the viral genome, the virus enters the cell

A. The virus enters the cell, host enzymes replicate the viral genome, enzymes transcribe the viral genome into mRNA

What is the function of reverse transcriptase in retroviruses? A. It hydrolyzes the host cell's DNA. B. It uses viral RNA as a template for DNA synthesis. C. It converts host cell RNA into viral DNA. D. It translates viral RNA into proteins. E. It uses viral RNA as a template for making complementary RNA strands.

B. It uses viral RNA as a template for DNA synthesis.

Which of the following represents a difference between viruses and viroids? A. Viruses infect many types of cells, whereas viroids infect only prokaryotic cells. B. Viruses have capsids composed of protein, whereas viroids have no capsids. C. Viruses contain introns, whereas viroids have only exons. D. Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA. E. Viruses cannot pass through plasmodesmata, whereas viroids can.

B. Viruses have capsids composed of protein, whereas viroids have no capsids.

Which of the following can be effective in preventing the onset of viral infection in humans? A. taking vitamins B. getting vaccinated C. taking antibiotics D. applying antiseptics E. taking nucleoside analogs that inhibit transcription

B. getting vaccinated

RNA viruses require their own supply of certain enzymes because A. host cells rapidly destroy the viruses. B. host cells lack enzymes that can replicate the viral genome. C. these enzymes translate viral mRNA into proteins. D. these enzymes penetrate host cell membranes.

B. host cells lack enzymes that can replicate the viral genome.

In Figure 17.2, when new viruses are being assembled (IV), what mediates the assembly? A. host cell DNA polymerase B. nothing; they self-assemble C. host cell mRNA D. viral RNA

B. nothing; they self-assemble

Which of the three types of viruses shown in Figure 17.1 would you expect to include glycoproteins? A. I only B. II only C. I and II only D. all three

C. I and II only

A human pandemic is A. a viral disease that infects all humans. B. a flu that kills more than 1 million people. C. an epidemic that extends around the world. D. a virus that increases in mortality rate as it spreads.

C. an epidemic that extends around the world.

Which of the following characteristics, structures, or processes is common to both bacteria and viruses? A. metabolism B. ribosomes C. genetic material composed of nucleic acid D. cell division

C. genetic material composed of nucleic acid

Which of the following series best reflects what we know about how the flu virus moves between species? A. An avian flu virus undergoes several mutations and rearrangements such that it is able to be transmitted to other birds and then to humans. B. The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected. C. A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans. D. An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus; this enables it to be transmitted to a human host. E. An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates and is passed to a new species such as a bird, the virus mutates and can be transmitted to humans.

E. An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates and is passed to a new species such as a bird, and the virus mutates and can be transmitted to humans

Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host? A. It is able to spread to a large number of new hosts quickly because the new hosts have no immunological memory of them. B. The new virus replicates quickly and undergoes rapid adaptation to a series of divergent hosts. C. A change in environmental conditions such as weather patterns quickly forces the new virus to invade new areas. D. Sporadic outbreaks will be followed almost immediately by a widespread pandemic. E. The newly emerging virus will die out rather quickly or will mutate to be far less lethal.

E. The newly emerging virus will die out rather quickly or will mutate to be far less lethal.

Most molecular biologists think that viruses originated from fragments of cellular nucleic acid. Which of the following observations supports this theory? A. Viruses contain either DNA or RNA. B. Viruses are enclosed in protein capsids rather than plasma membranes. C. Viruses can reproduce only inside host cells. D. Viruses can infect both prokaryotic and eukaryotic cells. E. Viral genomes are usually similar to the genome of the host cell.

E. Viral genomes are usually similar to the genome of the host cell.

Which viruses have single-stranded RNA that acts as a template for DNA synthesis? A. lytic phages B. proviruses C. viroids D. bacteriophages E. retroviruses

Retroviruses