CHAPTER 1: Microbial Life: Origin and Discovery
MULTIPLE CHOICE
1. Viruses are
a. infectious agents that infect exclusively multicellular organisms.
b. noncellular particles that take over the metabolism of a cell to generate more virus
particles.
c. pathogens that replicate in complex growth media.
d. cellular particles that belong to the archaea domain.
e. microbes that consist of lipid membrane–enclosed genomes.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe | 1.1b List examples of microbes
MSC: Remembering
2. Analysis of DNA sequences reveals
a. the ancient convergence of two cell types (i.e., prokaryotes and eukaryotes).
b. that prokaryotes and eukaryotes evolved from a common ancestral cell.
c. that bacteria share a common ancestor with archaea but not with eukarya.
d. that prokaryotes are cells with a nucleus.
e. that the genome of Haemophilus influenzae has about 2 billion base pairs.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Understanding
,3. Which of these groups are considered to be microbes but NOT considered to be cells?
a. viruses d. protists
b. bacteria e. filamentous fungi
c. archaea
ANS: A DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe | 1.1c Describe some problems with the definition
of a microbe MSC: Understanding
4. A microbe is commonly defined as a ________ that requires a microscope to be seen.
a. virus d. multicellular eukaryote
b. bacterium e. living organism
c. single-cellular prokaryote
ANS: E DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe MSC: Remembering
5. Which one of the following statements regarding microbial cells is FALSE?
a. Microbial cells acquire food, gain energy to build themselves, and respond to
environmental change.
b. Most single-celled organisms require a microscope to render them visible, but some
bacterial cells are large enough to be seen with naked eyes.
c. Microbes function as individual entities.
d. Many microbes form complex multicellular assemblages.
e. Viruses are not considered microbial cells.
ANS: C DIF: Easy REF: 1.1
, OBJ: 1.1a Recall the definition of a microbe MSC: Understanding
6. Which of the following statements is FALSE?
a. A genome is the total genetic information contained in an organism’s chromosomal DNA.
b. If a microbe’s genome includes genes for nitrogenase, that microbe probably can fix
nitrogen.
c. By comparing DNA sequences of different organisms, we can figure out how closely
related they are.
d. Fred Sanger developed the first applicable DNA sequencing method.
e. Fred Sanger completed the sequences of Haemophilus influenzae.
ANS: E DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Remembering
7. The first cellular genomes to be sequenced were those of
a. humans. d. prions.
b. bacteria. e. fungi.
c. viruses.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Remembering
8. The environment of early Earth may have contained all of the following EXCEPT
a. ferrous iron. d. oxygen.
b. methane. e. hydrogen gas.
, c. ammonia.
ANS: D DIF: Medium REF: Special Topic 1.1
OBJ: 1.1a Recall the definition of a microbe MSC: Remembering
9. The development of the theory of the “RNA world” resulted from the discovery of
a. archaea. d. ribozymes.
b. prions. e. endosymbionts.
c. bacteria.
ANS: D DIF: Medium REF: 1.6
OBJ: 1.6b Explain how studies on microbes fostered our knowledge of DNA function and
enhanced DNA technology MSC: Remembering
10. What is the evidence that living cells existed on Earth up to 3.8 billion years ago?
a. microfossils d. Martian folded rock formations
b. 16S ribosomal RNA e. diatom shells
c. Miller and Urey’s experiments
ANS: A DIF: Medium REF: Special Topic 1.1
OBJ: 1.5a Explain why microbes can be challenging to classify taxonomically | 1.5b Outline
how microbial classification has changed over time MSC: Remembering
11. What did van Leeuwenhoek discover using microscopic observations before and after drinking
hot beverages?
a. Heat did not kill microbes.
b. Heat killed microbes.
c. Heat did not kill algae.
MULTIPLE CHOICE
1. Viruses are
a. infectious agents that infect exclusively multicellular organisms.
b. noncellular particles that take over the metabolism of a cell to generate more virus
particles.
c. pathogens that replicate in complex growth media.
d. cellular particles that belong to the archaea domain.
e. microbes that consist of lipid membrane–enclosed genomes.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe | 1.1b List examples of microbes
MSC: Remembering
2. Analysis of DNA sequences reveals
a. the ancient convergence of two cell types (i.e., prokaryotes and eukaryotes).
b. that prokaryotes and eukaryotes evolved from a common ancestral cell.
c. that bacteria share a common ancestor with archaea but not with eukarya.
d. that prokaryotes are cells with a nucleus.
e. that the genome of Haemophilus influenzae has about 2 billion base pairs.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Understanding
,3. Which of these groups are considered to be microbes but NOT considered to be cells?
a. viruses d. protists
b. bacteria e. filamentous fungi
c. archaea
ANS: A DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe | 1.1c Describe some problems with the definition
of a microbe MSC: Understanding
4. A microbe is commonly defined as a ________ that requires a microscope to be seen.
a. virus d. multicellular eukaryote
b. bacterium e. living organism
c. single-cellular prokaryote
ANS: E DIF: Easy REF: 1.1
OBJ: 1.1a Recall the definition of a microbe MSC: Remembering
5. Which one of the following statements regarding microbial cells is FALSE?
a. Microbial cells acquire food, gain energy to build themselves, and respond to
environmental change.
b. Most single-celled organisms require a microscope to render them visible, but some
bacterial cells are large enough to be seen with naked eyes.
c. Microbes function as individual entities.
d. Many microbes form complex multicellular assemblages.
e. Viruses are not considered microbial cells.
ANS: C DIF: Easy REF: 1.1
, OBJ: 1.1a Recall the definition of a microbe MSC: Understanding
6. Which of the following statements is FALSE?
a. A genome is the total genetic information contained in an organism’s chromosomal DNA.
b. If a microbe’s genome includes genes for nitrogenase, that microbe probably can fix
nitrogen.
c. By comparing DNA sequences of different organisms, we can figure out how closely
related they are.
d. Fred Sanger developed the first applicable DNA sequencing method.
e. Fred Sanger completed the sequences of Haemophilus influenzae.
ANS: E DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Remembering
7. The first cellular genomes to be sequenced were those of
a. humans. d. prions.
b. bacteria. e. fungi.
c. viruses.
ANS: B DIF: Easy REF: 1.1
OBJ: 1.1d Explain the implications of microbial genome sequencing
MSC: Remembering
8. The environment of early Earth may have contained all of the following EXCEPT
a. ferrous iron. d. oxygen.
b. methane. e. hydrogen gas.
, c. ammonia.
ANS: D DIF: Medium REF: Special Topic 1.1
OBJ: 1.1a Recall the definition of a microbe MSC: Remembering
9. The development of the theory of the “RNA world” resulted from the discovery of
a. archaea. d. ribozymes.
b. prions. e. endosymbionts.
c. bacteria.
ANS: D DIF: Medium REF: 1.6
OBJ: 1.6b Explain how studies on microbes fostered our knowledge of DNA function and
enhanced DNA technology MSC: Remembering
10. What is the evidence that living cells existed on Earth up to 3.8 billion years ago?
a. microfossils d. Martian folded rock formations
b. 16S ribosomal RNA e. diatom shells
c. Miller and Urey’s experiments
ANS: A DIF: Medium REF: Special Topic 1.1
OBJ: 1.5a Explain why microbes can be challenging to classify taxonomically | 1.5b Outline
how microbial classification has changed over time MSC: Remembering
11. What did van Leeuwenhoek discover using microscopic observations before and after drinking
hot beverages?
a. Heat did not kill microbes.
b. Heat killed microbes.
c. Heat did not kill algae.
