,CHAPTER 1: Microbial Life: Origin and Discovery
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MULTIPLE CHOICE
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1. Viruses are: v
a. infectious agents that infect multi-cellular organisms v v v v v
b. noncellular particles that take over the metabolism of a cell to generate more virus
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particles
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c. pathogens that replicate in complex growth media v v v v v v
d. cellular particles that belong to the archaea domain v v v v v v v
e. microbes that consist of lipid membrane enclosed genomes v v v v v v v
ANS: B DIF: Easy REF: 1.1 TOP: I.A|I.Bv v v
MSC: Remembering v
2. Analysis of DNA sequences reveals: v v v v
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 v v v v v v v v
c. that bacteria share common ancestor with archaea, but not with eukarya
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d. prokaryotes are cells with a nucleus v v GF v v
e. the genome of Haemophilus influenzae has about 2 billion base pairs
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ANS: B DIF: Easy REF: 1.1 TOP: I.A |I.B
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MSC: Remembering v
3. Which of these groups are considered to be microbes but NOT considered to be cells?
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a. viruses d. protists v v
b. bacteria e. filamentous fungi v
c. archaea
ANS: A DIF: Easy REF: 1.1 TOP: I.A.i v
MSC: Remembering v
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: Easy REF: 1.1 TOP: I.A.i|I.A.ii
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MSC: Remembering v
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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environmentalchange.
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, 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. v v v v
d. Many microbes form complex multicellular assemblages.
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e. Viruses are not considered as microbial cells. v v v v v v
ANS: C DIF: Easy REF: 1.1 TOP: I.A.i |I.A.ii v v v
MSC: Remembering v
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 fix nitroge n.
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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.
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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 DIF: Easy REF: 1.1 TOP: I.B v
MSC: Remembering v
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 DIF: Easy REF: 1.1 TOP:
MSC: Remembering v vI.B.i
8. The environment of early Earth may have contained all of the following EXCEPT:
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a. ferrous iron d. oxygenv v v
b. methane e. hydrogen gas v
c. ammonia
ANS: D DIF: Easy
REF: Special Topic 1.1TOP: II.D v v v
MSC: Remembering
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9. The development of the theory of the ―RNA world‖ resulted from the discovery of:
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a. archaea d. ribozymes v v
b. prions e. endosymbionts
c. bacteria
ANS: D DIF: Medium
REF: Special Topic 1.1TOP: II.D v v v
MSC: Remembering
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10. Which microbes may resemble those of the earliest life forms?
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a. archaea d. cyanobacteria v v
b. photosynthetic algae e. protists v
c. viruses
ANS: A DIF: Medium
REF: Special Topic 1.1TOP: II.D v v v
MSC: Remembering
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11. Early metabolism may have been catalyzed by:
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a. DNA d. amino acids v v
b. RNA e. carbohydrates