Chapter 17
What is the function of reverse transcriptase in retroviruses?
It uses viral RNA as a template for DNA synthesis.
Why do RNA viruses appear to have higher rates of mutation?
Replication of their genomes does not involve proofreading.
Which of the following is the most probable fate of a newly emerging virus that causes high mortality in its host?
The newly emerging virus will die out rather quickly or will mutate to be far less lethal.
A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur?
The plants would develop the typical symptoms of TMV infection
Which of the following series best reflects what we know about how the flu virus moves between species?
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 can be effective in preventing the onset of viral infection in humans?
Getting vaccinated
Most molecular biologists think that viruses originated from fragments of cellular nucleic acid. Which of the following observations supports this theory?
Viral genomes are usually similar to the genome of the host cell.
Which of the following is the best predictor of how much damage a virus causes?
ability of the infected cell to undergo normal cell division
