Bio chapter 17

3) In the figure above, at the arrow marked 11, what enzyme is being utilized?

D) host cell RNA polymerase

4) In the figure above, when new viruses are being assembled during the step labeled lV, hoe is the assembly of the new virus particles completed?

D) the proteins self-assemble

1) Which of the following statements correctly describes viruses?

A) They cannot reproduce without a host cell.

16) Which of the following statements correctly describes one difference between vertical and horizontal transmission of plant viruses?

A) Vertical transmission is transmission of a virus from a parent plant to its progeny, and horizontal transmission is one plant spreading the virus to another plant.

17) Which of the following statements correctly describes the best predictor of how much damage a virus cause?

A) ability of the infected cell to undergo normal cell division

5) In t1971, David Baltimore described a scheme for classifying viruses based on how the virus produces mRNA, referred to as the Baltimore requirements. The table below shows the result of testing five viruses (A-E) for nuclease sensitivity, the ability of the viral genome to act as an mRNA, and the presence (+) or absence (-) of each virus's own polymerase.

B) B

12) What is the function of reverse transcriptase in retroviruses?

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

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

B) Replication of their genomes does not involve correcting errors in genome replication.

6) Which of the following responses correctly lists the order of events in a generalized viral replicative cycle?

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

15) Which of the following statements accurately describes plant virus infections?

B) They are spread via the plasmodesmata

3) Which of the following statements correctly describes adenoviruses?

B) They contain DNA surrounded by a capsid

18) How do antiviral drugs help to treat viral infections?

B) They interfere with viral replication

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

B) getting vaccinated

5) RNA viruses require their own supply of certain enzymes because

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

3) The herpesviruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters. Some of the human ones are herpes simplex virus (HSV) types 1 and 11, causing facial and genital lesions, and the varicella zoster virus (VSV), causing chicken pox and shingles. Each of these three actively infects nervous tissue. Primarily infectious are fairly mild, but the virus Is not then cleared from the host: rather, viral genomes are maintained in cells in a latent phase. The virus can then reactivate, replicate again, and be infectious to others. If scientist are trying to use what they know about HSV to devise a means of protecting other people from being infected, which go the following would have the best chance of lowering the number of new cases of infection?

B) interference with new viral replication in preexisting cases

1) You isolate an infectious substance that is capable of causing disease in plants, but you do not know wether the infectious agent is a bacterium, virus, or prion. You have four methods at your disposal that you can use you analyze the substance in order to determine the nature of the infectious agent.

C) 111

2) You isolate an infectious substance that is capable of causing disease in plants, but you do not know wether the infectious agent is a bacterium, virus, or prion. You have four methods at your disposal that you can use you analyze the substance in order to determine the nature of the infectious agent.

C) 111 only

8) Which of the following statements correctly describes the lysogenic cycle of lambda phage?

C) The phage genome replicates along with the host genome

10) 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?

C) The plants would develop the typical symptoms of TMV infection.

3) A human pandemic is

C) an epidemic that extends around the world.

5) The herpesviruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters. Some of the human ones are herpes simplex virus (HSV) types 1 and 11, causing facial and genital lesions, and the varicella zoster virus (VSV), causing chicken pox and shingles. Each of these three actively infects nervous tissue. Primarily infectious are fairly mild, but the virus Is not then cleared from the host: rather, viral genomes are maintained in cells in a latent phase. The virus can then reactivate, replicate again, and be infectious to others. In order to be able to remain latent in an infected live cell, HSV must be able to shut down what process?

C) apoptosis of a virally infected cell

1) Which of the following characteristics structures, or processes is common to both bacteria and viruses?

C) genetic material composed of nucleic acid

1) Which of the three types of viruses shown in the figure above would you expect to include glycoproteins as part of their overall structure?

D) 1 and 11 only

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

D) A large number of phages are released at a time.

19) which of the following series of events best reflects what we know about how the flu virus moves between species?

D) 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.

2) Which of the following nucleic acids make(s) up viral genomes?

D) DNA or RNA

4) A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced will have

D) T4 protein and T4 DNA.

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

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

4) The herpesviruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters. Some of the human ones are herpes simplex virus (HSV) types 1 and 11, causing facial and genital lesions, and the varicella zoster virus (VSV), causing chicken pox and shingles. Each of these three actively infects nervous tissue. Primarily infectious are fairly mild, but the virus Is not then cleared from the host: rather, viral genomes are maintained in cells in a latent phase. The virus can then reactivate, replicate again, and be infectious to others. In electron micrographs of HSV infection, it can be seen that the intact virus initially reacts with cell-surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsid go from being full to being "empty". Which of the following statements best describes these observations?

D) The viral envelope mediates entry into the celll, the capsid docks onto the nuclear membrane, and the genome is all that enters the nucleus.

9) Most molecular biologist think that viruses originated from naked bits of cellular nucleic acid. Which of the following observations supports this theory?

D) Viral genes are usually similar to the genome of the host cell.

2) Emerging viruses arise by

D) all of the above

2) Which of the three types of viruses shown in the figure above would you expect to include a capsid(s) a start of their overall structure?

D) all three

5) Some people who have had a herpesvirus-mediated cold sore or genital sore may have flareups for the rest of their life. Why does this occur?

D) copies of the herpesvirus genome remaining as mini-chromosomes in some host cell nuclei

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

D) retroviruses

4) Which of the following characteristics determine a virus's host range?

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