× Didn't find what you were looking for? Ask a question
  
  
  
Top Posters
Since Sunday
22
22
19
18
18
17
17
16
16
16
16
16
  
wrote...
Donated
Trusted Member
Posts: 1571
8 years ago
Biology, 8e (Campbell)
Chapter 19  

Viruses

Multiple-Choice Questions

1) What characteristics of electron microscopes make them most useful for studying viruses?
A) high energy electrons with high penetrance
B) requirement that specimens be viewed in a vacuum
C) necessity for specimens to be dry and fixed
D) shorter wavelengths providing higher resolution
E) use of magnetic fields to focus electrons


Topic:  Concept 19.1
Skill:  Application/Analysis

2) 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) size of the viral capsomeres
B) RNA versus DNA genome
C) double versus single strand genomes
D) size and shape of the capsid
E) glycoproteins of the envelope


Topic:  Concept 19.1
Skill:  Synthesis/Evaluation

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


Topic:  Concept 19.1
Skill:  Synthesis/Evaluation

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


Topic:  Concept 19.1
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.1
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.1
Skill:  Knowledge/Comprehension

7) 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) herpesvirus
C) smallpox
D) HIV
E) hepatitis virus


Topic:  Concept 19.2
Skill:  Application/Analysis

Use the following information to answer the following questions.

In 1971, David Baltimore described a scheme for classifying viruses based on how the virus produces mRNA.

The table below shows the results of testing five viruses for nuclease specificity, the ability of the virus to act as an mRNA, and presence (+) or absence (-) of its own viral polymerase.

Virus Nuclease    Sensitivity    Genome as mRNA    Polymerase
A    Dnase    -   -
B    Rnase    +   -
C    Dnase    -   +
D    Rnase    -   +
E    Rnase    +   -
 
8) Given Baltimore's scheme, a positive sense single-stranded RNA virus such as the polio virus would be most closely related to which of the following?
A) T-series bacteriophages
B) retroviruses that require a DNA intermediate
C) single-stranded DNA viruses such as herpesviruses
D) nonenveloped double-stranded RNA viruses
E) linear double-stranded DNA viruses such as adenovirus


Topic:  Concept 19.2
Skill:  Synthesis/Evaluation

9) Based on the above table, which virus meets the Baltimore requirements for a retrovirus?


Topic:  Concept 19.2
Skill:  Application/Analysis

10) Based on the above table, which virus meets the requirements for a bacteriophage?


Topic:  Concept 19.2
Skill:  Application/Analysis

11) A linear piece of viral DNA of 8 kb can be cut with either of two restriction enzymes (X and Y). These are subjected to electrophoresis and produce the following bands:

 

Cutting the same 8 kb piece with both enzymes together results in bands at 4.0, 2.5, 1.0, and 0.5.

Of the possible arrangements of the sites given below, which one is most likely?

A)
  

B)
  

C)
  

D)
  

E)
  



Topic:  Concept 19.2
Skill:  Application/Analysis

12) 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) re-infection by a closely related herpesvirus of a different strain
B) re-infection by the same herpesvirus strain
C) co-infection with an unrelated virus that causes the same symptoms
D) copies of the herpesvirus genome permanently maintained in host nuclei
E) copies of the herpesvirus genome permanently maintained in host cell cytoplasm


Topic:  Concept 19.2
Skill:  Knowledge/Comprehension

13) In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. Therefore, which of the following would you expect of the genes of the bacteriophage?
A) regulation via acetylation of histones
B) positive control mechanisms rather than negative
C) control of more than one gene in an operon
D) reliance on transcription activators
E) utilization of eukaryotic polymerases


Topic:  Concept 19.2
Skill:  Synthesis/Evaluation

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


Topic:  Concept 19.2
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.2
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.2
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.2
Skill:  Knowledge/Comprehension

18) 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 more similar to the genome of the host cell than to the genomes of viruses that infect other cell types.


Topic:  Concept 19.2
Skill:  Synthesis/Evaluation

19) 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?
A) The plants would develop some but not all of the symptoms of the TMV infection.
B) The plants would develop symptoms typically produced by viroids.
C) The plants would develop the typical symptoms of TMV infection.
D) The plants would not show any disease symptoms.
E) The plants would become infected, but the sap from these plants would be unable to infect other plants.


Topic:  Concept 19.3
Skill:  Application/Analysis

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


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

21) 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.


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

Refer to the treatments listed below to answer the following questions.

You isolate an infectious substance that is capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at your disposal that you can use to analyze the substance in order to determine the nature of the infectious agent.
I.   treating the substance with nucleases that destroy all nucleic acids and then determining whether it is still infectious
II.   filtering the substance to remove all elements smaller than what can be easily seen under a light microscope
III.   culturing the substance by itself on nutritive medium, away from any plant cells
IV.   treating the sample with proteases that digest all proteins and then determining whether it is still infectious
 
23) Which treatment could definitively determine whether or not the component is a viroid?
A) I
B) II
C) III
D) IV
E) first II and then III


Topic:  Concept 19.3
Skill:  Application/Analysis

24) If you already knew that the infectious agent was either bacterial or viral, which treatment would allow you to distinguish between these two possibilities?
A) I
B) II
C) III
D) IV
E) either II or IV


Topic:  Concept 19.3
Skill:  Application/Analysis

25) Which treatment would you use to determine if the agent is a prion?
A) I only
B) II only
C) III only
D) IV only
E) either I or IV


Topic:  Concept 19.3
Skill:  Application/Analysis

26) Which of the following describes plant virus infections?
A) They can be controlled by the use of antibiotics.
B) They are spread throughout a plant by passing through the plasmodesmata.
C) They have little effect on plant growth.
D) They are seldom spread by insects.
E) They can never be inherited from a parent.


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

27) 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; 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; viroids can.


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

28) The difference between vertical and horizontal transmission of plant viruses is that
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.
B) vertical transmission is the spread of viruses from upper leaves to lower leaves of the plant, and horizontal transmission is the spread of a virus among leaves at the same general level.
C) vertical transmission is the spread of viruses from trees and tall plants to bushes and other smaller plants, and horizontal transmission is the spread of viruses among plants of similar size.
D) vertical transmission is the transfer of DNA from one type of plant virus to another, and horizontal transmission is the exchange of DNA between two plant viruses of the same type.
E) vertical transmission is the transfer of DNA from a plant of one species to a plant of a different species, and horizontal transmission is the spread of viruses among plants of the same species.


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

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


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

30) Which of the following is the best predictor of how much damage a virus causes?
A) ability of the infected cell to undergo normal cell division
B) ability of the infected cell to carry on translation
C) whether the infected cell produces viral protein
D) whether the viral mRNA can be transcribed
E) how much toxin the virus produces


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

31) Antiviral drugs that have become useful are usually associated with which of the following properties?
A) ability to remove all viruses from the infected host
B) interference with the viral reproduction
C) prevention of the host from becoming infected
D) removal of viral proteins
E) removal of viral mRNAs


Topic:  Concept 19.3
Skill:  Knowledge/Comprehension

32) 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.


Topic:  Concept 19.3
Skill:  Synthesis/Evaluation

33) 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.
Attached file
(69.77 KB)
Read 16984 times
1 Reply
Related Topics
Replies
wrote...
Educator
8 years ago
You are not allowed to post this kind of information.
The best way to say thank you is with a positive review:

  https://trustpilot.com/review/biology-forums.com 

Your support goes a long way!


Make a note request here
      
This topic is not open for further replies. Only administrators and moderators can reply. If you'd like to contribute to this topic, start a new thread and make reference to this one. Otherwise, contact a moderator for more options.
Explore
Post your homework questions and get free online help from our incredible volunteers.
Learn More
Improve Grades
Help Others
Save Time
Accessible 24/7
  118 People Browsing
Your Opinion
Do you believe in global warming?
Votes: 186

Previous poll results: Who's your favorite biologist?
Related Images
 930