Download Document

Name ______________________________ Class ___________________ Date __________________
Skills Worksheet
Directed Reading B
Section: 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
b. bacteria
c. nucleus
d.
host
2. What do many viruses cause?
a. decay
b. bacterial infections c.
cell growth
d.
diseases
IT’S A SMALL WORLD
3. How big are viruses?
a. bigger than bacteria
b. smaller than bacteria
c. one inch wide
d. one-quarter inch wide
4. Why can a virus’s effect on living things change?
a. Viruses disappear quickly.
b. Viruses change quickly.
c. Viruses change slowly.
d. Viruses never change.
5. Why are viruses hard to fight?
a. Viruses are large and change often.
b.
Viruses are small and change often.
c. Viruses are large and change slowly.
d.
Viruses are small and change slowly.
ARE VIRUSES LIVING?
6. How are viruses like living things?
a. Viruses contain protein and genetic material.
b.
Viruses eat and grow.
c. Viruses reproduce through binary fission.
d.
Viruses reproduce outside a host.
7. Which of the following statements is NOT true about viruses?
a. Viruses do not eat.
b. Viruses do not grow.
c. Viruses live on their own.
d. Viruses do not need oxygen.
8. Where do viruses reproduce?
a. inside a host cell
b. inside other viruses
c. inside dead cells
d. in the air
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
20
Bacteria and Viruses
Name ______________________________ Class ___________________ Date __________________
9. What is a living thing a virus lives on or in called?
a. a bacterium
b. a virus
c.
a disease
d.
a host
10. What do viruses force a host to make?
a. new cells
b. viruses
c. bacteria
d. chlorophyll
CLASSIFYING VIRUSES
11. Which is NOT a way of grouping viruses?
a. by shape
b. by size
c. by life cycle
d. by the type of diseases they cause
Read the description. Then, draw a line from the dot next to each description to the
matching word.
12. shape of tobacco mosaic
virus
13. shape of HIV and influenza
viruses
14. shape of viruses that attack
only bacteria
15. shape of polio virus
16. genetic material in cold, flu,
and AIDS viruses
17. protects genetic material and
helps viruses enter cells
18. genetic material in warts and
chickenpox viruses
•
•
•
•
•
•
•
a. spacecraft
b. spheres
c. crystals
d. cylinders
a. protein coat
b. DNA
c. RNA
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
Name ______________________________ Class ___________________ Date __________________
Directed Reading B continued
A DESTRUCTIVE HOUSE GUEST
Read the words in the box. Read the sentences. Fill in each blank with the word or phrase
that best completes the sentence.
19.
lysogenic
genetic
viruses
host
lytic
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
Read the description. Then, draw a line from the dot next to each description to the
matching word.
24. medicines that do not kill viruses
25. procedure that helps prevent viral
infections
26. type of medicine that keeps viruses
from reproducing
•
•
•
a. antiviral
b. antibiotics
c. vaccinations
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
22
Bacteria and Viruses