BIO 182 Test 5

9) Which of the following molecules make up the viral envelope? A) carbopeptides B) carboproteins C) proteosugars D) hosts membrane E) peptidocarbs

D) hosts membrane

12) Which of the following terms describes bacteriophage DNA that has become integrated into the host cell chromosome? A) intemperate bacteriophages B) plasmids C) T-even phages D) transposons E) prophages

E) prophages

29) What is the name given to viruses that are single-stranded RNA that acts as a template for DNA synthesis? A) viroids B) lytic phages C) bacteriophages D) proviruses E) retroviruses

E) retroviruses

28) Which is not a part of a virus A) ER B) Capsid C) genetic information D) envelope

A) ER

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

A) Viruses have capsids composed of protein, whereas viroids have no capsids.

10) Which of the following accounts for someone who has had a herpesvirus-mediated cold sore or genital sore getting flare-ups for the rest of life? A) copies of the herpesvirus genome permanently maintained in host nuclei B) copies of the herpesvirus genome permanently maintained in host cell cytoplasm C) re-infection by a closely related herpesvirus of a different strain D) co-infection with an unrelated virus that causes the same symptoms] E) re-infection by the same herpesvirus strain

A) copies of the herpesvirus genome permanently maintained in host nuclei

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

A) getting vaccinated

17) The capsid of a virus is composed of A) proteins B) simple sugars C) lipids D) fats

A) proteins

15) Most human-infecting viruses are maintained in the human population only. However, a zoonosis is a disease that is transmitted from other vertebrates to humans, at least sporadically, without requiring viral mutation. Which of the following is the best example of a zoonosis? A) rabies B) hepatitis virus C) smallpox D) HIV E) herpesvirus

A) rabies

11) Which of the following is characteristic of the lytic cycle? A) The viral genome replicates without destroying the host. B) A large number of phages is released at a time. C) The virus-host relationship usually lasts for generations. D) Viral DNA is incorporated into the host genome. E) Many bacterial cells containing viral DNA are produced.

B) A large number of phages is released at a time.

5) Which of the following series best reflects what we know about how the flu virus moves between species? A) The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected. B) 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. C) 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. D) A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans. E) 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) 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.

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

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

2) Why are viruses referred to as obligate parasites? A) They invariably kill any cell they infect. B) They cannot reproduce outside of a host cell. C) Viral DNA always inserts itself into host DNA. D) They must use enzymes encoded by the virus itself. E) They can incorporate nucleic acids from other viruses.

B) They cannot reproduce outside of a host cell.

6) Which of the following molecules make up the viral envelope? A) peptidocarbs B) glycoproteins C) carboproteins D) proteosugars E) carbopeptides

B) glycoproteins

16) The host range of a virus is determined by A) the proteins in the host's cytoplasm B) the proteins on its surface and that of the host C) the enzymes carried by the virus D) the enzymes produced by the virus before it infects the cell E) whether its nucleic acid is DNA or RNA

B) the proteins on its surface and that of the host

30) Why do RNA viruses appear to have higher rates of mutation? A) RNA nucleotides are more unstable than DNA nucleotides. B) RNA viruses are more sensitive to mutagens. C) Replication of their genomes does not involve the proofreading steps of DNA replication. D) RNA viruses replicate faster. E) RNA viruses can incorporate a variety of nonstandard bases.

C) Replication of their genomes does not involve the proofreading steps of DNA replication.

25) A virus will obtain it's membraneous envelope from what? A) it's capsid B) it's DNA C) host cell D) ER

C) host cell

8) Viral genomes vary greatly in size and may include from four genes to several hundred genes. Which of the following viral features is most apt to correlate with the size of the genome? A) RNA versus DNA genome B) glycoproteins of the envelope C) size and shape of the capsid D) double versus single strand genomes E) size of the viral capsomeres

C) size and shape of the capsid

26) Viral DNA is integrated into an animal cell's DNA is called a A) prophage B) Capsid C) Retrovirus D) Provirus

D) Provirus

13) Retroviruses hereditary information will transform inside of a host cell from what to what? A) RNA/RNA B) DNA/RNA C) DNA/DNA D) RNA/DNA

D) RNA/DNA

27) Which of these organisms do viruses not infect A) dogs B) plants C) bacteria D) all can be infected

D) all can be infected

7) Viral envelopes can best be analyzed with which of the following techniques? A) transmission electron microscopy B) staining and visualization with the light microscope C) immunofluorescent tagging of capsid proteins D) antibodies against specific proteins not found in the host membranes E) use of plaque assays for quantitative measurement of viral titer

D) antibodies against specific proteins not found in the host membranes

4) Which of the following statements describes the lysogenic cycle of Iambda phage? A) Certain environmental triggers can cause the phage to exit the host genome, switching from the lytic to the lysogenic. B) The phage DNA is incorporated by crossing over into any nonspecific site of the host cell's DNA. C) Most of the prophage genes are activated by the product of a particular prophage gene. D) After infection, the viral genes immediately turn the host cell into a Lambda-producing factory, and the host cell then lyses. E) The phage genome replicates along with the host genome.

E) The phage genome replicates along with the host genome.

3) A researcher lyses a cell that contains nucleic acid molecules and capsomeres 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? A) The plants would develop some but not all of the symptoms of the TMV infections. B) The plants would become infected, but the sap from these plants would be unable to infect other plants. C) The plants would not show any disease symptoms. D) The plants would develop symptoms typically produced by viroids. E) The plants would develop the typical symptoms of TBV infection.

E) The plants would develop the typical symptoms of TBV infection.

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

E) misfolded versions of normal brain protein

1) A light microscope is often used to inspect viruses.

False

18) A bacteriophage is a virus that attacks plants.

False

20) Lytic replication can take years until the virus replicates.

False

21) Vaccinations use interferon to attack the virus during replication.

False

22) Viruses are made up cells.

False

23) Antibiotics are useful in killing viral infections.

False

24) HIV can be cured with the use of antiviral drugs.

False

19) Viruses can be either RNA or DNA based.

True