Download DR10.3A Viruses

Name __________________________________
DR 10.3a: Viruses
_____ 1. What is a microscopic particle that enters and often destroys a cell?
a. a virus
c. a protein
b. a host
d. a bacterium
2. Name three diseases caused by viruses.
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IT’S A SMALL WORLD
_____ 3. About how many virus particles could fit in a single drop of blood?
a. about 5 billion
c. about 5 hundred thousand
b. about 5 million
d. about 5 thousand
_____ 4. A virus’s effect on living things changes because
a. they disappear quickly.
c. they change rapidly.
b. they change slowly.
d. they never change.
5. Why are scientists unable to accurately count the many types of viruses?
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ARE VIRUSES LIVING?
6. What are two ways viruses are like living things?
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7. What are four ways that viruses are not like living things?
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8. Where does a virus reproduce?
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9. The cell that a virus lives on or in is called a(n) .______________________
10. Once a virus has entered a living cell, what does it force the cell to do?
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CLASSIFYING VIRUSES
11. What characteristics do scientists use to group viruses?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
8
Bacteria and Viruses
Name __________________________________
Match the each description with the correct term.
_____ 12. shape of HIV and influenza viruses
a. crystals
_____ 13. shape of many viruses that attack only bacteria
b. spacecraft
_____ 14. shape of tobacco mosaic virus
c. spheres
_____ 15. shape of polio virus
d. cylinders
16. How does a virus’s protein coat help a virus?
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17. Give two examples of viruses that contain the genetic material DNA.
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18. Give three examples of viruses that contain the genetic material RNA.
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A DESTRUCTIVE HOUSE GUEST
_____ 19. The cycle in which viruses attack living cells and turn them into virus
factories is called the
a. factory cycle.
c. lytic cycle.
b. reproduction cycle.
d. virus cycle.
Number the following events in the order of their occurrence in the lytic cycle.
_____ 20. The host cell replicates the virus’s genes.
_____ 21. The host cell is destroyed.
_____ 22. The virus’s genes enter the host.
_____ 23. The virus finds a host cell.
24. Describe the lysogenic cycle.
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25. How do many antiviral medications work?
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26. What are three ways people can help prevent viral infections?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
9
Bacteria and Viruses