Download Directed Reading 10.3b Viruses

Name ______________________________ Class ___________________ Date __________________
Directed Reading 10.3b Viruses
Circle the letter of the best answer for each question.
1. What tiny particle gets inside a cell and often destroys the cell?
a. virus
c. nucleus
b. bacteria
d. host
2. What do many viruses cause?
a. decay
c. cell growth
b. bacterial infections
d. diseases
IT’S A SMALL WORLD
3. How big are viruses?
a. bigger than bacteria
c. one inch wide
b. smaller than bacteria
d. one-quarter inch wide
4. Why can a virus’s effect on living things change?
a. Viruses disappear quickly.
c. Viruses change slowly.
b. Viruses change quickly.
d. Viruses never change.
5. Viruses are hard to fight because they are
a. large and change often.
c. large and change slowly.
b. small and change often.
d. small and change slowly.
ARE VIRUSES LIVING?
6. Viruses are like living things because they
a. have protein and genetic stuff.
c. reproduce with binary fission.
b. eat and grow.
d. reproduce outside a host.
7. Which of the following statements is NOT true about viruses?
a. Viruses do not eat.
c. Viruses live on their own.
b. Viruses do not grow.
d. Viruses do not need oxygen.
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
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Bacteria and Viruses
Name ______________________________ Class ___________________ Date __________________
8. Where do viruses reproduce?
a. inside a host cell
c. inside dead cells
b. inside other viruses
d. in the air
9. What is a living thing a virus lives on or in called?
a. a bacterium
c. a disease
b. a virus
10. What do viruses force a host to make?
d. a host
a. new cells
c. bacteria
b. viruses
d. chlorophyll
CLASSIFYING VIRUSES
11. Which is NOT a way of grouping viruses?
a. by shape
c. by life cycle
b. by size
d. by the diseases they cause
Select the word that best matches each description.
12. shape of tobacco mosaic virus
a.spacecraft
13. shape of HIV and influenza viruses
b.spheres
14. shape of viruses that attack only bacteria
c.crystals
15. shape of polio virus
d.cylinders
16. genetic material in cold, flu, and AIDS
viruses
a.protein coat
b.DNA
17. protects genetic material and helps viruses
enter cells
c.RNA
18. genetic material in warts and chickenpox
viruses
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
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Bacteria and Viruses
Name ______________________________ Class ___________________ Date __________________
A DESTRUCTIVE HOUSE GUEST
Select the word or phrase that best completes the sentence.
a. lysogenic
c. genetic
b. viruses
d. host
e. lytic
19. Viruses attack cells and turn them into virus factories in the
___________________ cycle.
20. In the lytic cycle, a virus joins a cell and injects it with the virus’s
______________________material.
21. During the lytic cycle, a virus’s genes take over the host and
make______________________.
22. Newly made viruses break out of the______________________, which
then dies.
A Time Bomb
23. New cells get a copy of the virus when the host divides in the
______________________cycle.
Treating a Virus
Select the word to best match each description.
24. medicines that do not kill viruses
a. antiviral
25. procedure that helps prevent viral
infections
b. antibiotics
c. vaccinations
26. type of medicine that keeps viruses
from reproducing
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
21
Bacteria and Viruses