1. Chapter 19
Viruses
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

2. Which of the following is not a property of life shared by prokaryotic cells, eukaryotic cells, and viruses?
nucleic acids used to store hereditary information
order and complexity in arrangement of biological molecules
the ability to process energy through metabolic reactions
the capacity to evolve
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

3. You have isolated viral particles from a patient, but you are not sure whether they are rhinoviruses or influenza viruses. The presence of which class of biological molecules would allow you to distinguish between the two types of virus?
RNA
phospholipids
proteins
glycoproteins
DNA
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

4. A culture of E. coli bacteria was inoculated with a phage virus
A culture of E. coli bacteria was inoculated with a phage virus. The graphs show bacterial and phage numbers before and after irradiation with UV light. This virus is probably a ___ phage and is ___.
λ; temperate
λ; virulent
T4; virulent
T4; lytic
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

5. Before exposure to UV light, the phages described in the previous question were most likely in the ___ cycle.
lytic
virulent
prophage
lysogenic
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

6. People with nonfunctional chemokine membrane receptors on their helper T cells as a result of a genetic mutation are immune to HIV infection. Why?
HIV cannot enter the host cell.
Reverse transcriptase cannot transcribe RNA to DNA.
Viral mRNA cannot be transcribed from the integrated provirus.
Viruses cannot bud from the host cell.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

7. Bacteriophages were grown in a medium containing radioactive sulfur (35S) and radioactive phosphorous (32P), which are incorporated into proteins and DNA, respectively. If these phages were used to infect a bacterial culture, which isotope would be detected within the infected bacteria?
35S
32P
both
neither
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

8. AZT is a nucleoside analog used to treat HIV infections
AZT is a nucleoside analog used to treat HIV infections. It is a thymine (T) nucleoside with an azide group instead of the hydroxyl group found in typical thymine nucleosides. Which step does AZT hamper in the reproductive cycle of the HIV virus?
entry into the cell
reverse transcription of DNA from RNA
transcription of RNA from proviral DNA
viral assembly within the cell
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

9. You have isolated a sample from an animal suffering from an unknown disease. Which of the following tests would allow you to determine that the animal has a prion disease?
Pass the sample through a filter to remove bacteria and see if the filtrate is still infectious.
Treat the sample with nuclease and see if it is still infectious.
Treat the sample with protease and see if it is still infectious.
Heat the sample to normal cooking temperatures and see if it is still infectious.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.

10. Which of the following most likely describes the vertical transmission of a plant virus?
The plant shows symptoms of disease after being grazed on by herbivores.
Sap from one plant is rubbed on the leaves of a second plant; both plants eventually show disease symptoms.
Seeds are planted and reared under protected conditions, but mature plants show disease symptoms.
After a gardener prunes several plants with the same shears, they all show disease symptoms.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.