,CHAPTER 1: Microbial Life: Origin and Discovery
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MULTIPLE CHOICE
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1. Viruses are: XF
a. infectious agents that infect multi-cellular organisms XF XF XF XF XF
b. noncellular particles that take over the metabolism of a cell to generate more viruspa
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rticles
c. pathogens that replicate in complex growth media XF XF XF XF XF XF
d. cellular particles that belong to the archaea domain
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e. microbes that consist of lipid membrane enclosed genomes XF XF XF XF XF XF XF
ANS: B DIF:
X F Easy REF: 1.1 XFXFXF TOP: I.A | I.B
X F XF XF
MSC: Remembering
X F
2. Analysis of DNA sequences reveals:
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a. the ancient convergence of two cell types, i.e., prokaryotes and eukaryotes
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b. prokaryotes and eukaryotes evolved from a common ancestral cell XF XF XF XF XF XF XF XF
c. that bacteria share common ancestor with archaea, but not with eukarya
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d. prokaryotes are cells with a nucleus XF XF XF XF XF
e. the genome of Haemophilus influenzae has about 2 billion base pairs
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ANS: B DIF:
X F Easy REF: 1.1 XFXFXF TOP: I.A | I.B
X F XF XF
MSC: Remembering
X F
3. Which of these groups are considered to be microbes but NOT considered to be cells?
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a. viruses d. protists
b. bacteria e. filamentous fungi XF
c. archaea
ANS: A DIF:
X F Easy REF: 1.1 XFXFXF TOP: I.A.i X F
MSC: Remembering
X F
4. A microbe is commonly defined as:
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a. a virus that requires a microscope to be seen
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b. a bacterium that requires a microscope to be seen
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c. a single-cellular prokaryote that requires a microscope to be seen
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d. a multicellular eukaryote that requires a microscope to be seen
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e. a living organism that requires a microscope to be seen
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ANS: E DIF:
X F Easy REF: 1.1 XFXFXF TOP: I.A.i | I.A.ii
X F XF XF
MSC: Remembering
X F
5. Which one of the following statements regarding microbial cells is NOT true?
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a. Microbial cells acquire food, gain energy to build themselves, and respond to
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environmental change. XF
, b. Most single-celled organisms require a microscope to render them visible, but some
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bacterial cells are large enough to be seen with naked eyes.
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c. Microbes function as individual entities.
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d. Many microbes form complex multicellular assemblages.
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e. Viruses are not considered as microbial cells.
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ANS: C X FDIF: Easy REF: 1.1 XFXFXF TOP: I.A.i | I.A.ii X F XF XF
MSC: Remembering
X F
6. Which of the following statements is FALSE?
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a. A genome is the total genetic information contained in an organism’s chromosomal DNA.
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b. If a microbe’s genome includes genes for nitrogenase, that microbe probably can fixnitrogen.
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c. By comparing DNA sequences of different organisms, we can figure out how closely
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related they are. XF XF
d. Fred Sanger developed the first applicable DNA sequencing method.
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e. Fred Sanger completed the sequences of Haemophilus influenzae.
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ANS: E X FDIF: Easy REF: 1.1 XFXFXF TOP: I.B X F
MSC: Remembering
X F
7. The first cellular genomes to be sequenced were those of:
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a. humans d. prions
b. bacteria e. fungi
c. viruses
ANS: B X FDIF: Easy REF: 1.1 XFXFXF TOP: I.B.i X F
MSC: Remembering
X F
8. The environment of early Earth may have contained all of the following EXCEPT:
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a. ferrous iron XF d. oxygen
b. methane e. hydrogen gas XF
c. ammonia
ANS: D X F DIF: Easy
REF: Special Topic 1.1TOP:
XF XF XF X
F X F II.D
MSC: Remembering X F
9. The development of the theory of the ―RNA world‖ resulted from the discovery of:
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a. archaea d. ribozymes
b. prions e. endosymbionts
c. bacteria
ANS: D X F DIF: Medium
REF: Special Topic 1.1TOP:
XF XF XF X
F X F II.D
MSC: Remembering X F
10. Which microbes may resemble those of the earliest life forms?
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a. archaea d. cyanobacteria
b. photosynthetic algae e. protists XF
c. viruses
ANS: A X F DIF: Medium
REF: Special Topic 1.1TOP:
XF XF XF X
F X F II.D
MSC: Remembering X F
11. Early metabolism may have been catalyzed by:
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a. DNA d. amino acids XF
b. RNA e. carbohydrates