Chapter 19: Viruses

Which of the following characteristics, structures, or processes is common to both bacteria and

viruses?

• cell division

• genetic material composed of nucleic acid

• ribosomes

• metabolism

RNA viruses require their own supply of certain enzymes because ...

• these enzymes translate viral mRNA into proteins.

• these enzymes penetrate host cell membranes.

• host cells rapidly destroy the viruses.

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

Which of the following statements correctly describes one characteristic of the lytic cycle of viral replication?

• Viral DNA is incorporated into the host genome.

• Many bacterial cells containing viral DNA are produced.

• The viral genome replicates without destroying the host.

• A large number of phages are released at a time.

Which viruses have single-stranded RNA that acts as a template for DNA synthesis?

• lytic phages

• retroviruses

• proviruses

• bacteriophages

• viroids

What is the function of reverse transcriptase in retroviruses?

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

• It converts host cell RNA into viral DNA.

• It hydrolyzes the host cell's DNA.

• It uses viral RNA as a template for making complementary RNA strands.

Why do RNA viruses tend to have unusually high rates of mutation?

• RNA viruses can incorporate a variety of nonstandard bases.

• Replication of their genomes does not involve proofreading.

• RNA viruses replicate faster.

• RNA nucleotides are more unstable than DNA nucleotides.

Tags

NGSS.HS-LS4-2

Which of the following processes can be effective in preventing the onset of viral infection in humans?

• applying antiseptics

• taking antibiotics

• getting vaccinated

• taking vitamins

Which of the following statements correctly describes the most probable fate of a newly emerging virus that causes high mortality in its host?

• Sporadic outbreaks will be followed almost immediately by a widespread pandemic.

• The new virus replicates quickly and undergoes rapid adaptation to a series of divergent hosts.

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

• It is able to spread to a large number of new hosts quickly because the new hosts have no immunological memory of them.

At the arrow marked II, what enzyme(s) is (are) being utilized?

• viral DNA polymerase

• host cell DNA and RNA polymerases

• reverse transcriptase

• host cell RNA polymerase

• host cell DNA polymerase

When new viruses are being assembled (IV), what mediates the assembly?

• assembly proteins coded for by the viral genes

• assembly proteins coded for by the host nucleus

• host cell chaperones

• nothing; the proteins self-assemble