Name _________________________________
Date ________________
Chapter 2 Review Sheet: Bacteria and Viruses
Viruses
1. Why are viruses considered parasites? What is a host?
Viruses destroy their host cell. The host is the cell which the virus attaches to and
forces to create more viruses. (Viruses do NOT eat the host cell; they don’t eat at
all!)
2. Why are viruses considered nonliving?
Viruses are NOT made of cells, they don’t eat or use energy, they don’t
grow/develop
3. How do viruses get the resources they need to multiply?
Viruses inject their genetic material into a host cell and force the cell to make
more viruses
4. What is the best treatment for a viral infection?
Bed rest and fluids
5. How does a vaccine work?
A vaccine stimulates our natural defenses (our immune system); the vaccine
teaches our immune system to recognize and destroy specific bacteria and
viruses.
6. How do viruses multiply? Be able to interpret graphics of viral replication.
Virus attaches to a bacterium or other cell, injects its genetic material into the
cell, forces the cell to start making virus parts and assembling new viruses,
eventually the cell bursts and the viruses are released.
7. Draw and label the structure of a virus.
Bacteria
1. What are three main shapes of bacterial cells? Be able to use a
taxonomic key to identify bacteria.
Round, long (rod), spiral
2. How do bacteria cells reproduce?
Binary fission – asexual reproduction, cell copies itself
Conjugation – sexual reproduction with another virus, makes offspring different
from parent
3. What positive roles do bacteria play in our bodies?
Bacteria help us digest foods, make vitamins, and compete with bad bacteria
4. Why are bacterial cells called decomposers?
Break down wastes and return “basic chemicals” to the environment
5. What does “antibiotic resistance” mean?
A bacteria that cannot be killed by an antibiotic
6. Describe two main ways infectious diseases can be spread.
Direct contact with a contaminated surface or person
Indirect contact by inhaling droplets in the air
7. List some ways you can prevent getting an infectious disease.
WASH YOUR HANDS, avoid contact with contaminated surfaces and sick
people
8. How do endospores benefit bacteria?
Help bacteria to survive extreme environmental conditions (too cold/hot/wet/dry)
9. Draw and label the structure of a typical bacteria.