,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
Chapter 1: An Invisible World
* = Correct answer
Multiple Choice
1. Which of the following is true of the microbial world?
A. All microbes are harmful.
B. Humans could survive without microbes.
C. Many microbes are helpful.*
D. Most microbes are pathogenic.
Difficulty: Easy
ASM Standard: 23, 24
2. Which of the following is when humans first suspected the existence of microbes?
A. during the Industrial Revolution
B. in prehistoric times*
C. in the last century
D. within the last 500 years
Difficulty: Easy
ASM Standard: 23
3. Which individual first observed unicellular organisms, which he called “animalcules,” using
a microscope he developed?
A. Robert Koch
B. Louis Pasteur
C. Thucydides
D. Antonie van Leeuwenhoek*
Difficulty: Easy
ASM Standard: 6
4. To reduce the risk of open flame from Bunsen burners, microbiologists are increasingly using
which of the following devices for easy, rapid benchtop sterilization of small pieces of
equipment?
A. autoclaves
B. ethylene oxide
C. incubators
D. microincinerators*
Difficulty: Easy
ASM Standard: 36
Page 1 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
5. The Swedish botanist known for having developed an important biological classification
system is which of the following people?
A. Ernst Haeckel
B. Carolus Linnaeus*
C. Louis Pasteur
D. Robert Whittaker
Difficulty: Easy
ASM Standard: N/A
6. Which kingdom was the only one found in Empire Prokaryota?
A. Animalia
B. Fungi
C. Monera*
D. Protista
Difficulty: Easy
ASM Standard: N/A
7. Which are the three currently accepted domains?
A. Archaea, Bacteria, and Eukarya*
B. Archaea, Prokaryota, and Eukaryota
C. Bacteria, Fungi, and Protista
D. Bacteria, Prokaryota, and Eukarya
Difficulty: Easy
ASM Standard: N/A
8. Which two taxonomic units are typically used to identify an organism when using binomial
nomenclature?
A. domain and kingdom
B. genus and family
C. genus and species*
D. phylum and class
Difficulty: Easy
ASM Standard: N/A
9. Which of the following is not true about the process of fermentation?
A. It can help preserve foods, preventing spoilage.
B. It converts sugars to organic acids, alcohols, and/or gases such as carbon dioxide.
C. It is carried out exclusively by unicellular eukaryotes such as yeast.*
D. It is used to make foods such as cheese and bread.
Difficulty: Moderate
ASM Standard: 11, 23, 26
Page 2 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
10. The Romans may have reduced their risk of waterborne infectious diseases by using which of
the following?
A. a variety of pharmaceutical products
B. aqueducts and a sewer system*
C. prophylactic antibiotics
D. quarantine of people with leprosy
Difficulty: Moderate
ASM Standard: 23
11. For which of the following is Thucydides known?
A. developing an effective sewer system in ancient Greece, helping to reduce levels of
disease in cities
B. observing microbes, using a microscope, for the first time, even distinguishing between
bacteria and fungi
C. proposing that disease was caused by microorganisms
D. realizing that people who had been infected by the Athenian plague had immunity to
reinfection*
Difficulty: Moderate
ASM Standard: 23, 31
12. Ernst Haeckel proposed a classification system consisting of which of the following
subgroups?
A. five kingdoms
B. four kingdoms*
C. two domains and three kingdoms
D. two domains and five kingdoms
Difficulty: Moderate
ASM Standard: N/A
13. Viruses not included in phylogenetic trees for which of the following reasons?
A. It is too difficult to observe their characteristics.
B. They are acellular and nonliving.*
C. They do not have any genes, which prevents genetic analysis.
D. They lack a nucleus.
Difficulty: Moderate
ASM Standard: 5
14. Which is the best description of the primary purpose of a phylogeny?
A. Phylogenies show all the alterative names for each species.
B. Phylogenies show all the common names for each species.
C. Phylogenies show evolutionary relatedness between organisms.*
Page 3 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
D. Phylogenies show interactions between species in a shared habitat.
Difficulty: Moderate
ASM Standard: 5
15. Current phylogenetic analyses include which of the following?
A. information from a range of sources, including morphological, genetic, and biochemical
data*
B. information on visible similarities only
C. information regarding how to classify organisms on the basis of external morphological
characteristics and visible behaviors
D. varied morphological and structural characteristics, with preference for leaving historical
classifications to prevent confusion
Difficulty: Moderate
ASM Standard: 5
16. Diatoms are classified within which of the following domains?
A. Archaea
B. Bacteria
C. Eukarya*
D. Prokaryota
Difficulty: Moderate
ASM Standard: N/A
17. Horizontal gene transfer involves which of the following?
A. any transfer of genes in a laboratory setting
B. the transfer of genes from a virus to a bacterium or vice versa but not any other form of
gene transfer
C. the transfer of genes from one individual to another, including from one species to
another, but not from parent to offspring*
D. the transfer of genes from parent to offspring
Difficulty: Moderate
ASM Standard: 2, 4
18. Bacteria are generally identified to species by using which of the following?
A. a combination of genetic, biochemical, and microscopic approaches*
B. a combination of microscopic and physiological approaches, but not genetics
C. primarily characteristics such as motility that can be visualized using microscopy
D. primarily morphological characteristics of individual cells
Difficulty: Moderate
ASM Standard: 34, 36
Page 4 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
19. For taxonomic classification of microbes, serological tests typically are used to do which of
the following?
A. determine complete genome sequences for microbes
B. identify proteins on the basis of their reaction with specific antibodies*
C. run analyses to identify whether particular genes are present
D. visualize microbial external morphology
Difficulty: Moderate
ASM Standard: 34, 36
20. Which of the following is true of bacterial strains?
A. They are closely related subtypes within a bacterial species that may or may not have
similar properties.*
B. They are informal bacterial groupings used for medical distinctions but not recognized for
classification purposes.
C. They are more distantly related to each other than are members of a single bacterial
species.
D. They are very similar bacteria with almost identical properties.
Difficulty: Moderate
ASM Standard: 5
21. Bergey’s Manual of Systematic Bacteriology is used primarily as which of the following?
A. a guide to bacterial shapes
B. a historical account of changes in classification techniques
C. a list and characterization of all known medically relevant microbes
D. a reference for bacterial classification*
Difficulty: Moderate
ASM Standard: 34
22. Which of the following indicates how bacteria and viruses typically compare in size?
A. Bacteria are indistinguishable from viruses.
B. Bacteria are much larger than viruses.*
C. Bacteria are much smaller than viruses.
D. Bacteria are similar in size to viruses.
Difficulty: Easy
ASM Standard: N/A
23. Viruses are classified as which of the following?
A. Archaea
B. Bacteria
C. Eukarya
D. distinct from the three-domain system*
Page 5 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
Difficulty: Moderate
ASM Standard: 4
24. Which of the following is not a curved bacterial shape?
A. bacillus*
B. spirillum
C. spirochete
D. vibrio
Difficulty: Easy
ASM Standard: 34
25. Based just on the name, which of the following groups of bacteria contains entirely species
that consume organic compounds for food?
A. cyanobacteria
B. green nonsulfur bacteria
C. green sulfur bacteria
D. nonphotosynthetic bacteria*
Difficulty: Moderate
ASM Standard: 11, 13, 20
26. Chitin cell walls are characteristic of which taxonomic group?
A. algae
B. archaea
C. bacteria
D. fungi*
Difficulty: Moderate
ASM Standard: 20
27. Yeasts are which of the following?
A. a type of algae
B. a type of protist
C. any unicellular microbe
D. unicellular fungi*
Difficulty: Moderate
ASM Standard: 20
28. The cell walls of archaeans often contain which of the following substances?
A. cellulose
B. chitin
C. peptidoglycan
D. pseudopeptidoglycan*
Page 6 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
Difficulty: Moderate
ASM Standard: 20
29. Which of the following is not true of archaeans?
A. Some species live on the human body.
B. They are genetically distinct from bacteria.
C. They are only found in extreme environments.*
D. They have substantial metabolic differences from bacteria.
Difficulty: Difficult
ASM Standard: 20
30. Which of the following is not true of algae?
A. All the algae are classified together in one similar group closely related to green plants.*
B. Ingredients made from algae, including carrageenan, are used in food products.
C. They are being used to develop biofuels.
D. They are sometimes multicellular.
Difficulty: Moderate
ASM Standard: 20, 23, 26
31. Oral thrush is caused by which type of organism?
A. algae
B. bacteria
C. fungi*
D. protists
Difficulty: Moderate
ASM Standard: 23
32. Mycotoxins are produced by which type of organism?
A. archaeans
B. heterotrophic protists
C. molds*
D. protozoans
Difficulty: Moderate
ASM Standard: 23
33. Which of the following is not a common use of fungi?
A. the production of alcoholic beverages
B. the production of carrageenan*
C. the production of cyclosporine
D. the production of penicillin
Page 7 of 17
Chapter 1: An Invisible World
Chapter 1: An Invisible World
* = Correct answer
Multiple Choice
1. Which of the following is true of the microbial world?
A. All microbes are harmful.
B. Humans could survive without microbes.
C. Many microbes are helpful.*
D. Most microbes are pathogenic.
Difficulty: Easy
ASM Standard: 23, 24
2. Which of the following is when humans first suspected the existence of microbes?
A. during the Industrial Revolution
B. in prehistoric times*
C. in the last century
D. within the last 500 years
Difficulty: Easy
ASM Standard: 23
3. Which individual first observed unicellular organisms, which he called “animalcules,” using
a microscope he developed?
A. Robert Koch
B. Louis Pasteur
C. Thucydides
D. Antonie van Leeuwenhoek*
Difficulty: Easy
ASM Standard: 6
4. To reduce the risk of open flame from Bunsen burners, microbiologists are increasingly using
which of the following devices for easy, rapid benchtop sterilization of small pieces of
equipment?
A. autoclaves
B. ethylene oxide
C. incubators
D. microincinerators*
Difficulty: Easy
ASM Standard: 36
Page 1 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
5. The Swedish botanist known for having developed an important biological classification
system is which of the following people?
A. Ernst Haeckel
B. Carolus Linnaeus*
C. Louis Pasteur
D. Robert Whittaker
Difficulty: Easy
ASM Standard: N/A
6. Which kingdom was the only one found in Empire Prokaryota?
A. Animalia
B. Fungi
C. Monera*
D. Protista
Difficulty: Easy
ASM Standard: N/A
7. Which are the three currently accepted domains?
A. Archaea, Bacteria, and Eukarya*
B. Archaea, Prokaryota, and Eukaryota
C. Bacteria, Fungi, and Protista
D. Bacteria, Prokaryota, and Eukarya
Difficulty: Easy
ASM Standard: N/A
8. Which two taxonomic units are typically used to identify an organism when using binomial
nomenclature?
A. domain and kingdom
B. genus and family
C. genus and species*
D. phylum and class
Difficulty: Easy
ASM Standard: N/A
9. Which of the following is not true about the process of fermentation?
A. It can help preserve foods, preventing spoilage.
B. It converts sugars to organic acids, alcohols, and/or gases such as carbon dioxide.
C. It is carried out exclusively by unicellular eukaryotes such as yeast.*
D. It is used to make foods such as cheese and bread.
Difficulty: Moderate
ASM Standard: 11, 23, 26
Page 2 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
10. The Romans may have reduced their risk of waterborne infectious diseases by using which of
the following?
A. a variety of pharmaceutical products
B. aqueducts and a sewer system*
C. prophylactic antibiotics
D. quarantine of people with leprosy
Difficulty: Moderate
ASM Standard: 23
11. For which of the following is Thucydides known?
A. developing an effective sewer system in ancient Greece, helping to reduce levels of
disease in cities
B. observing microbes, using a microscope, for the first time, even distinguishing between
bacteria and fungi
C. proposing that disease was caused by microorganisms
D. realizing that people who had been infected by the Athenian plague had immunity to
reinfection*
Difficulty: Moderate
ASM Standard: 23, 31
12. Ernst Haeckel proposed a classification system consisting of which of the following
subgroups?
A. five kingdoms
B. four kingdoms*
C. two domains and three kingdoms
D. two domains and five kingdoms
Difficulty: Moderate
ASM Standard: N/A
13. Viruses not included in phylogenetic trees for which of the following reasons?
A. It is too difficult to observe their characteristics.
B. They are acellular and nonliving.*
C. They do not have any genes, which prevents genetic analysis.
D. They lack a nucleus.
Difficulty: Moderate
ASM Standard: 5
14. Which is the best description of the primary purpose of a phylogeny?
A. Phylogenies show all the alterative names for each species.
B. Phylogenies show all the common names for each species.
C. Phylogenies show evolutionary relatedness between organisms.*
Page 3 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
D. Phylogenies show interactions between species in a shared habitat.
Difficulty: Moderate
ASM Standard: 5
15. Current phylogenetic analyses include which of the following?
A. information from a range of sources, including morphological, genetic, and biochemical
data*
B. information on visible similarities only
C. information regarding how to classify organisms on the basis of external morphological
characteristics and visible behaviors
D. varied morphological and structural characteristics, with preference for leaving historical
classifications to prevent confusion
Difficulty: Moderate
ASM Standard: 5
16. Diatoms are classified within which of the following domains?
A. Archaea
B. Bacteria
C. Eukarya*
D. Prokaryota
Difficulty: Moderate
ASM Standard: N/A
17. Horizontal gene transfer involves which of the following?
A. any transfer of genes in a laboratory setting
B. the transfer of genes from a virus to a bacterium or vice versa but not any other form of
gene transfer
C. the transfer of genes from one individual to another, including from one species to
another, but not from parent to offspring*
D. the transfer of genes from parent to offspring
Difficulty: Moderate
ASM Standard: 2, 4
18. Bacteria are generally identified to species by using which of the following?
A. a combination of genetic, biochemical, and microscopic approaches*
B. a combination of microscopic and physiological approaches, but not genetics
C. primarily characteristics such as motility that can be visualized using microscopy
D. primarily morphological characteristics of individual cells
Difficulty: Moderate
ASM Standard: 34, 36
Page 4 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
19. For taxonomic classification of microbes, serological tests typically are used to do which of
the following?
A. determine complete genome sequences for microbes
B. identify proteins on the basis of their reaction with specific antibodies*
C. run analyses to identify whether particular genes are present
D. visualize microbial external morphology
Difficulty: Moderate
ASM Standard: 34, 36
20. Which of the following is true of bacterial strains?
A. They are closely related subtypes within a bacterial species that may or may not have
similar properties.*
B. They are informal bacterial groupings used for medical distinctions but not recognized for
classification purposes.
C. They are more distantly related to each other than are members of a single bacterial
species.
D. They are very similar bacteria with almost identical properties.
Difficulty: Moderate
ASM Standard: 5
21. Bergey’s Manual of Systematic Bacteriology is used primarily as which of the following?
A. a guide to bacterial shapes
B. a historical account of changes in classification techniques
C. a list and characterization of all known medically relevant microbes
D. a reference for bacterial classification*
Difficulty: Moderate
ASM Standard: 34
22. Which of the following indicates how bacteria and viruses typically compare in size?
A. Bacteria are indistinguishable from viruses.
B. Bacteria are much larger than viruses.*
C. Bacteria are much smaller than viruses.
D. Bacteria are similar in size to viruses.
Difficulty: Easy
ASM Standard: N/A
23. Viruses are classified as which of the following?
A. Archaea
B. Bacteria
C. Eukarya
D. distinct from the three-domain system*
Page 5 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
Difficulty: Moderate
ASM Standard: 4
24. Which of the following is not a curved bacterial shape?
A. bacillus*
B. spirillum
C. spirochete
D. vibrio
Difficulty: Easy
ASM Standard: 34
25. Based just on the name, which of the following groups of bacteria contains entirely species
that consume organic compounds for food?
A. cyanobacteria
B. green nonsulfur bacteria
C. green sulfur bacteria
D. nonphotosynthetic bacteria*
Difficulty: Moderate
ASM Standard: 11, 13, 20
26. Chitin cell walls are characteristic of which taxonomic group?
A. algae
B. archaea
C. bacteria
D. fungi*
Difficulty: Moderate
ASM Standard: 20
27. Yeasts are which of the following?
A. a type of algae
B. a type of protist
C. any unicellular microbe
D. unicellular fungi*
Difficulty: Moderate
ASM Standard: 20
28. The cell walls of archaeans often contain which of the following substances?
A. cellulose
B. chitin
C. peptidoglycan
D. pseudopeptidoglycan*
Page 6 of 17
,OpenStax Microbiology Test Bank
Chapter 1: An Invisible World
Difficulty: Moderate
ASM Standard: 20
29. Which of the following is not true of archaeans?
A. Some species live on the human body.
B. They are genetically distinct from bacteria.
C. They are only found in extreme environments.*
D. They have substantial metabolic differences from bacteria.
Difficulty: Difficult
ASM Standard: 20
30. Which of the following is not true of algae?
A. All the algae are classified together in one similar group closely related to green plants.*
B. Ingredients made from algae, including carrageenan, are used in food products.
C. They are being used to develop biofuels.
D. They are sometimes multicellular.
Difficulty: Moderate
ASM Standard: 20, 23, 26
31. Oral thrush is caused by which type of organism?
A. algae
B. bacteria
C. fungi*
D. protists
Difficulty: Moderate
ASM Standard: 23
32. Mycotoxins are produced by which type of organism?
A. archaeans
B. heterotrophic protists
C. molds*
D. protozoans
Difficulty: Moderate
ASM Standard: 23
33. Which of the following is not a common use of fungi?
A. the production of alcoholic beverages
B. the production of carrageenan*
C. the production of cyclosporine
D. the production of penicillin
Page 7 of 17
