Chapter 18:
Viruses and Bacteria
Practice Test
1.
What layer surrounds a virus, giving it an exact shape that will bind to a host cell?
a.
the pili
b.
the protein coat
c.
the cell wall
d.
the flagella
Hint
2.
Because it is prokaryotic, a bacterial cell does not have __________.
a.
a plasma membrane
b.
enzymes
c.
a nucleus
d.
ribosomes
Hint
3.
Which portion of a bacteriophage allows it to attach to the host bacterium?
a.
the cell wall
b.
the nucleic acid
c.
the plasma membrane
d.
the tail fibers
Hint
4.
Which of the following happens to the viral nucleic acid during a lytic cycle?
a.
the viral DNA is used to attach the bacteriophage to the host cell`s receptors
b.
the viral DNA immediately takes over the host cell genetic material
c.
the viral DNA becomes integrated into the host cell`s chromosomes
d.
the viral DNA forms a provirus
Hint
5.
How is a provirus related to disease symptoms?
a.
the provirus continually lyses cells, causing disease symptoms
b.
the provirus secretes powerful toxins that make the host ill
c.
the provirus can produce endospores during unfavorable times
d.
the provirus periodically shifts to a lytic cycle, causing disease symptoms
Hint
6.
When a virus becomes a provirus , it __________.
a.
stops reproduction of the host cell
b.
causes cell lysis, releasing multiple copies of the virus
c.
interferes with the normal functioning of the host cell
d.
is replicated right along with the host cell`s chromosomes
Hint
7.
In _______, bacteria convert gaseous nitrogen into ammonia, nitrites and nitrates.
a.
attachment
b.
binary fission
c.
nitrogen fixation
d.
conjugation
Hint
8.
Bacteria that cannot survive in the presence of oxygen are __________.
a.
obligate anaerobes
b.
archaebacteria
c.
obligate saprobes
d.
obligate aerobes
Hint
9.
Why is penicillin ineffective against viruses?
a.
Viruses do not have a metabolism.
b.
Viruses do not have cell walls.
c.
Viruses are not alive.
d.
Viruses do not reproduce.
Hint
10.
Bacteria carry on a simple form of sexual reproduction called __________.
a.
nitrogen fixation
b.
lysogeny
c.
conjugation
d.
binary fission
Hint
11.
Which group includes organisms that live in oxygen-free environments?
a.
cyanobacteria
b.
Eubacteria
c.
Archaebacteria
d.
photosynthetic autotrophs
Hint
12.
What type of nucleic acid do retroviruses contain?
a.
reverse transcriptase
b.
proteins
c.
RNA
d.
DNA
Hint
13.
When do bacteria form endospores?
a.
when environmental conditions become unfavorable
b.
when they get ready to reproduce
c.
when they get ready to carry out conjugation
d.
when they carry out photosynthesis
Hint
14.
How does a virus recognize its host cell?
a.
by the pili on the outside of the cell wall
b.
the spikes on the host cell recognize attachment molecules in the viral nucleic acid
c.
a protein on the virus matches the shape of a molecule in the plasma membrane of the host
d.
the cell wall has extensions that fit particular envelope molecules on the virus
Hint
15.
What is meant by the term "streptococcus"?
a.
special bacteria that are spiral-shaped
b.
bacteria that are round and arranged in grapelike clusters
c.
bacteria that are rods and in groups
d.
bacteria that are round and arranged in chains
Hint
