Name __________________________________
Chapter 18: Viruses and Bacteria
Date ___________________________
Section 18.1
1. What is a virus?
2.
What are bacteria?
Section 18.2: Viruses
3. Viruses have very simple structure. A virion is made up of a protein ______________ surrounding
their genetic material.
4. Viruses can only be reproduced after they have infected a living ________ cell.
5. Label the diagram below of a bacteriophage shown in Figure 18.5
6. Discuss the Lytic infection pathway shown in Figure 18.6.
7. Discuss a Lysogenic infection pathway also shown in Figure 18.6
8. How does the lysogenic pathway differ from the lytic pathway?
Section 18.3
9. Give 4 examples of human illnesses caused by a virus.
a. _________________________________
b. _________________________________
c. _________________________________
d. _________________________________
10. What is a vaccine?
11. What are vaccines made of?
Section 18.4: Bacteria
12. What type of cell would be found in all bacteria? Prokaryotic or Eukaryotic
13. There are three basic shapes to all bacteria. Label the shapes shown below using Figure 18.12
14. Label the diagram below of a bacterial cell using Figure 18.15
15. When conditions are good for growth, bacteria usually reproduce by binary fission. Discuss this
method.
16. Under poor conditions, bacteria will use other methods to gain genetic variation. Discuss each of the
following:
a. Conjugation
b. Endospores
Section 18.5: Good bacteria
17. How are bacteria mutualistic symbionts in us?
18. Other than acting as the major decomposers in any ecosystem, bacteria also serve an important role by
being able to fix atmospheric nitrogen. Discuss nitrogen fixation by bacteria.
Section 18.6: Bacteria and Diseases
19. What is an antibiotic?
20. Why won’t a doctor prescribe an antibiotic to someone with a cold?