Practice Ch 19- Viruses PDF

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Practice Ch 19- Viruses...

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practice chapeter 19 Name___________________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which of the three types of viruses shown above would you expect to include glycoproteins? A) I only B) II only C) III only D) I and II only 2) Viruses _____. A) manufacture their own ATP, proteins, and nucleic acids B) use the host cell to copy themselves and make viral proteins C) use the host cell to copy themselves and then viruses synthesize their own proteins D) metabolize food and produce their own ATP 3) What is the main structural difference between enveloped and nonenveloped viruses? A) Enveloped viruses have their genetic material enclosed by a layer made only of protein. B) Nonenveloped viruses have only a phospholipid membrane, while enveloped viruses have two membranes, the other one being a protein capsid.

C) Enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane. D) Both types of viruses have a capsid and phospholipid membrane; but in the nonenveloped virus the genetic material is between these two membranes, while in the enveloped virus the genetic material is inside both membranes.

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

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5) If a viral host cell has a mutation that interferes with the addition of carbohydrates to proteins in the Golgi, which of the following could likely result? A) The viral envelope proteins would not be glycosylated and might not arrive at the host plasma membrane.

B) The viral capsid proteins would not be glycosylated and might not arrive at the host plasma membrane.

C) The viral core proteins would not be glycosylated and might not arrive at the host plasma membrane. D) The virus would be unable to reproduce within the host cell.

6) Effective antiviral drugs are usually associated with which of the following properties? A) interference with viral replication B) prevention of the host from becoming infected C) removal of viral proteins D) removal of viral mRNAs 7) Which of the following processes within viral replication is the greatest source of genetic variation in RNA virus populations?

A) High mutation rate due to lack of proofreading of RNA genome replication errors. B) Transcription from the host cell RNA polymerase introduces numerous mutations. C) Capsid proteins from the host cell can replace the viral capsid. D) Viral RNA is translated by host cell ribosomes. 8) The host range of a virus is determined by _____. A) the enzymes carried by the virus B) whether its nucleic acid is DNA or RNA C) the proteins in the host's cytoplasm D) the proteins on its surface and that of the host 9) 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 a 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

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10) In the figure, when new viruses are being assembled at the point marked IV, what mediates the assembly? A) host cell chaperones B) assembly proteins coded for by the host nucleus C) assembly proteins coded for by the viral genes D) nothing; they self-assemble 11) HIV is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. What are the practical consequences of these findings?

A) HIV can be transmitted more easily from person to person than the flu virus B) The flu virus can be transmitted more easily from person to person than HIV C) This property of HIV makes it more likely to be a pandemic than the flu virus D) Disinfecting surfaces is more important to reduce the spread of HIV than the flu

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12) The first class of drugs developed to treat AIDS, such as AZT, were known as reverse transcriptase inhibitors. They worked because they _____.

A) targeted and destroyed the viral genome before it could be reverse transcribed into DNA B) bonded to the dsDNA genome of the virus in such a way that it could not separate for replication to occur

C) bonded to the viral reverse transcriptase enzyme, thus preventing the virus from making a DNA copy of its RNA genome

D) prevented host cells from producing the enzymes used by the virus to replicate its genome 13) Which of the following statements describes the lysogenic cycle of lambda (λ) 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) The phage DNA is copied and exits the cell as a phage. 14) Which viruses have single-stranded RNA that acts as a template for DNA synthesis? A) proviruses B) viroids C) bacteriophages D) retroviruses 15) What is the function of reverse transcriptase in retroviruses? A) It uses viral RNA as a template for DNA synthesis. B) It converts host cell RNA into viral DNA. C) It translates viral RNA into proteins. D) It uses viral RNA as a template for making complementary RNA strands.

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Answer Key Testname: PRACTICE CH 19- VIRUSES

1) D 2) B 3) C 4) C 5) A 6) A 7) A 8) D 9) C 10) D 11) B 12) C 13) C 14) D 15) A

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