OpenStax Microbiology
Chapter 1: An Invisible World
Page 0 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
OpenStax Microbiology
Chapter 1: An Invisible World
Multiple Choice
1. Which of the following foods is NOT made by fermentation?
A. beer
B. bread
C. cheese
D. orange juice
Answer
D
2. Who is considered the “father of Western medicine”?
A. Marcus Terentius Varro
B. Thucydides
C. Antonie van Leeuwenhoek
D. Hippocrates
Answer
D
3. Who was the first to observe “animalcules” under the microscope?
A. Antonie van Leeuwenhoek
B. Ötzi the Iceman
C. Marcus Terentius Varro
D. Robert Koch
Answer
A
4. Who proposed that swamps might harbor tiny, disease-causing animals too small to see?
A. Thucydides
B. Marcus Terentius Varro
C. Hippocrates
D. Louis Pasteur
Answer
B
5. Which of the following was NOT a kingdom in Linnaeus’s taxonomy?
A. animal
B. mineral
C. protist
D. plant
Answer
C
6. Which of the following is a correct usage of binomial nomenclature?
A. Homo Sapiens
B. homo sapiens
C. Homo sapiens
D. Homo Sapiens
Answer
C
7. Which scientist proposed adding a kingdom for protists?
Page 1 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
A. Carolus Linnaeus
B. Carl Woese
C. Robert Whittaker
D. Ernst Haeckel
Answer
D
8. Which of the following is NOT a domain in Woese and Fox’s phylogenetic tree?
A. Plantae
B. Bacteria
C. Archaea
D. Eukarya
Answer
A
9. Which of the following is the standard resource for identifying bacteria?
A. Systema Naturae
B. Bergey’s Manual of Determinative Bacteriology
C. Woese and Fox’s phylogenetic tree
D. Haeckel’s General Morphology of Organisms
Answer
B
10. Which of the following types of microorganisms is photosynthetic?
A. yeast
B. virus
C. helminth
D. alga
Answer
D
11. Which of the following is a prokaryotic microorganism?
A. helminth
B. protozoan
C. cyanobacterium
D. mold
Answer
C
12. Which of the following is acellular?
A. virus
B. bacterium
C. fungus
D. protozoan
Answer
A
13. Which of the following is a type of fungal microorganism?
A. bacterium
B. protozoan
C. algae
D. yeast
Page 2 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Answer
D
14. Which of the following is not a subfield of microbiology?
A. bacteriology
B. botany
C. clinical microbiology
D. virology
Answer
B
Fill in the Blank
15. Thucydides is known as the father of _______________.
Answer
Scientific history
16. Researchers think that Ötzi the Iceman may have been infected with _____ disease.
Answer
Lyme
17. The process by which microbes turn grape juice into wine is called _______________.
Answer
fermentation
18. In binomial nomenclature, an organism’s scientific name includes its ________ and
__________.
Answer
genus, species
19. Haeckel proposed adding the kingdoms ________ and ________ to his phylogenetic tree.
Answer
Protista and Monera
20. __________ are organisms without membrane-bound nuclei.
Answer
Prokaryotes
21. ______ are microorganisms that are not included in phylogenetic trees because they are
acellular.
Answer
Viruses
22. A ________ is a disease-causing microorganism.
Answer
pathogen
23. Multicellular parasitic worms studied by microbiologists are called ___________.
Answer
helminths
24. The study of viruses is ___________.
Answer
virology
25. The cells of prokaryotic organisms lack a _______.
Answer
nucleus
Page 3 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Short Answer
26. What did Thucydides learn by observing the Athenian plague?
Answer
He saw that people who had been infected by the disease but recovered did not become infected
again when they came into contact with sick people. This shows an early understanding of the
concept of immunity.
27. Why was the invention of the microscope important for microbiology?
Answer
With a light microscope, scientists could finally see different kinds of microbes and observe their
characteristics.
28. What are some ways people use microbes?
Answer
People can use microbes to make fermented foods, to clean up the environment, and to prevent
and treat infectious diseases.
29. What is a phylogenetic tree?
Answer
A phylogenetic tree is a diagram showing how different organisms are thought to be
evolutionarily related.
30. Which of the five kingdoms in Whittaker’s phylogenetic tree are prokaryotic, and which are
eukaryotic?
Answer
Prokaryotic: Monera; Eukaryotic: Protista, Animalia, Fungi, Plantae
31. What molecule did Woese and Fox use to construct their phylogenetic tree?
Answer
small subunit rRNA
32. Name some techniques that can be used to identify and differentiate species of bacteria.
Answer
Gram staining, DNA/RNA analysis, biochemical assays, and serological testing
33. Describe the differences between bacteria and archaea.
Answer
Archaea and bacteria have different evolutionary histories, genes, metabolic pathways, cell
walls, and membrane lipids.
34. Name three structures that various protozoa use for locomotion.
Answer
They can use hair-like cilia, tail-like flagella, or pseudopods (“false feet”).
35. Describe the actual and relative sizes of a virus, a bacterium, and a plant or animal cell.
Answer
A virus is about 100 nm and is 10 times smaller than a bacterium (~1 µm), which is at least 10
times smaller than a plant or animal cell (10–100 µm).
Critical Thinking
36. Explain how the discovery of fermented foods likely benefited our ancestors.
Answer
Page 4 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Besides enhancing the taste of many foods, fermentation is one of the oldest methods of
preserving perishable foods. This means fermented foods lasted longer and were less likely to
spoil and cause illness.
37. What evidence would you use to support this statement: Ancient people thought that disease
was transmitted by things they could not see.
Answer
The Romans built sewer and water systems to protect against disease. The concept of
quarantining people with leprosy is found in the Bible. The Roman Marcus Terentius Varro
proposed that disease could be caused by “certain minute creatures . . . which cannot be seen by
the eye.”
38. Why is using binomial nomenclature more useful than using common names?
Answer
In binomial nomenclature, each organism has a unique name. Common names can vary between
different countries or even within a country. It can also be difficult to come up with common
names for very similar organisms.
39. Label the three Domains found on modern phylogenetic trees.
Answer
Bacteria (purple), Archaea (red), Eukarya (brown)
40. Contrast the behavior of a virus outside versus inside a cell.
Answer
Inside a host cell, viruses are able to reproduce. A virus is unable to reproduce when it is outside
of a cell.
41. Where would a virus, bacterium, animal cell, and a prion belong on this chart?
Page 5 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Answer
Virus at ~100 nm, bacterium at ~1 μm, animal cell at between 10–100 µm. Since a prion is a
protein, it would be located at about 10 nm.
This file is copyright 2016, Rice University. All Rights Reserved.
Page 6 of 7
,OpenStax Microbiology
Chapter 2: How We See the Invisible World
OpenStax Microbiology
Chapter 2: How We See the Invisible World
Multiple Choice
1. Which of the following has the highest energy?
A. light with a long wavelength
B. light with an intermediate wavelength
C. light with a short wavelength
D. It is impossible to tell from the information given.
Answer
C
2. You place a specimen under the microscope and notice that parts of the specimen begin to emit light
immediately. These materials can be described as _____________.
A. fluorescent
B. phosphorescent
C. transparent
D. opaque
Answer
A
3. Who was the first to describe “cells” in dead cork tissue?
A. Hans Janssen
B. Zaccharias Janssen
C. Antonie van Leeuwenhoek
D. Robert Hooke
Answer
D
4. Who is the probable inventor of the compound microscope?
A. Girolamo Fracastoro
B. Zaccharias Janssen
C. Antonie van Leeuwenhoek
D. Robert Hooke
Answer
B
5. Which would be the best choice for viewing internal structures of a living protist such as a
Paramecium?
A. a brightfield microscope with a stain
B. a brightfield microscope without a stain
C. a darkfield microscope
D. a transmission electron microscope
Answer
C
6. Which type of microscope is especially useful for viewing thick structures such as biofilms?
A. a transmission electron microscope
B. a scanning electron microscopes
C. a phase-contrast microscope
D. a confocal scanning laser microscope
E. an atomic force microscope
Answer
Page 1 of 5
,OpenStax Microbiology
Chapter 2: How We See the Invisible World
D
7. Which type of microscope would be the best choice for viewing very small surface structures of a cell?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
B
8. What type of microscope uses an annular stop?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
E
9. What type of microscope uses a cone of light so that light only hits the specimen indirectly, producing
a light image on a dark background?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
D
10. What mordant is used in Gram staining?
A. crystal violet
B. safranin
C. acid-alcohol
D. iodine
Answer
D
11. What is one difference between specimen preparation for a transmission electron microscope
(TEM) and preparation for a scanning electron microscope (SEM)?
A. Only the TEM specimen requires sputter coating.
B. Only the SEM specimen requires sputter-coating.
C. Only the TEM specimen must be dehydrated.
D. Only the SEM specimen must be dehydrated.
Answer
B
Fill-in-the-Blank
12. When you see light bend as it moves from air into water, you are observing _________.
Answer
refraction
13. A microscope that uses multiple lenses is called a _________ microscope.
Page 2 of 5
, OpenStax Microbiology
Chapter 2: How We See the Invisible World
Answer
compound
14. Chromophores that absorb and then emit light are called __________.
Answer
fluorochromes
15. In a(n) _______ microscope, a probe located just above the specimen moves up and down in response
to forces between the atoms and the tip of the probe.
Answer
atomic force microscope
16. What is the total magnification of a specimen that is being viewed with a standard ocular lens and a
40× objective lens?
Answer
400×
17. Ziehl-Neelsen staining, a type of _______ staining, is diagnostic for Mycobacterium tuberculosis.
Answer
acid-fast
18. The _______ is used to differentiate bacterial cells based on the components of their cell walls.
Answer
Gram stain
Short Answer
19. Explain how a prism separates white light into different colors.
Answer
White light consists of light waves of many different frequencies. A prism is a material with different
refractive indices for light of different frequencies. Thus, when white light passes through the prism,
waves of different frequencies are refracted in different directions; this appears to the human eye as a
spectrum of colors similar to a rainbow.
20. Why is Antonie van Leeuwenhoek’s work much better known than that of Zaccharias Janssen?
Answer
Van Leeuwenhoek published and publicized his work.
21. Why did the cork cells observed by Robert Hooke appear to be empty, as opposed to being full of
other structures?
Answer
The cork cells were dead and the structures observed were the cell walls.
22. What is the function of the condenser in a brightfield microscope?
Answer
It focuses light from the light source onto the specimen.
23. How could you identify whether a particular bacterial sample contained specimens with mycolic acid-
rich cell walls?
Answer
Acid-fast staining should be used.
24. Label each component of the brightfield microscope.
Page 3 of 5
Chapter 1: An Invisible World
Page 0 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
OpenStax Microbiology
Chapter 1: An Invisible World
Multiple Choice
1. Which of the following foods is NOT made by fermentation?
A. beer
B. bread
C. cheese
D. orange juice
Answer
D
2. Who is considered the “father of Western medicine”?
A. Marcus Terentius Varro
B. Thucydides
C. Antonie van Leeuwenhoek
D. Hippocrates
Answer
D
3. Who was the first to observe “animalcules” under the microscope?
A. Antonie van Leeuwenhoek
B. Ötzi the Iceman
C. Marcus Terentius Varro
D. Robert Koch
Answer
A
4. Who proposed that swamps might harbor tiny, disease-causing animals too small to see?
A. Thucydides
B. Marcus Terentius Varro
C. Hippocrates
D. Louis Pasteur
Answer
B
5. Which of the following was NOT a kingdom in Linnaeus’s taxonomy?
A. animal
B. mineral
C. protist
D. plant
Answer
C
6. Which of the following is a correct usage of binomial nomenclature?
A. Homo Sapiens
B. homo sapiens
C. Homo sapiens
D. Homo Sapiens
Answer
C
7. Which scientist proposed adding a kingdom for protists?
Page 1 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
A. Carolus Linnaeus
B. Carl Woese
C. Robert Whittaker
D. Ernst Haeckel
Answer
D
8. Which of the following is NOT a domain in Woese and Fox’s phylogenetic tree?
A. Plantae
B. Bacteria
C. Archaea
D. Eukarya
Answer
A
9. Which of the following is the standard resource for identifying bacteria?
A. Systema Naturae
B. Bergey’s Manual of Determinative Bacteriology
C. Woese and Fox’s phylogenetic tree
D. Haeckel’s General Morphology of Organisms
Answer
B
10. Which of the following types of microorganisms is photosynthetic?
A. yeast
B. virus
C. helminth
D. alga
Answer
D
11. Which of the following is a prokaryotic microorganism?
A. helminth
B. protozoan
C. cyanobacterium
D. mold
Answer
C
12. Which of the following is acellular?
A. virus
B. bacterium
C. fungus
D. protozoan
Answer
A
13. Which of the following is a type of fungal microorganism?
A. bacterium
B. protozoan
C. algae
D. yeast
Page 2 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Answer
D
14. Which of the following is not a subfield of microbiology?
A. bacteriology
B. botany
C. clinical microbiology
D. virology
Answer
B
Fill in the Blank
15. Thucydides is known as the father of _______________.
Answer
Scientific history
16. Researchers think that Ötzi the Iceman may have been infected with _____ disease.
Answer
Lyme
17. The process by which microbes turn grape juice into wine is called _______________.
Answer
fermentation
18. In binomial nomenclature, an organism’s scientific name includes its ________ and
__________.
Answer
genus, species
19. Haeckel proposed adding the kingdoms ________ and ________ to his phylogenetic tree.
Answer
Protista and Monera
20. __________ are organisms without membrane-bound nuclei.
Answer
Prokaryotes
21. ______ are microorganisms that are not included in phylogenetic trees because they are
acellular.
Answer
Viruses
22. A ________ is a disease-causing microorganism.
Answer
pathogen
23. Multicellular parasitic worms studied by microbiologists are called ___________.
Answer
helminths
24. The study of viruses is ___________.
Answer
virology
25. The cells of prokaryotic organisms lack a _______.
Answer
nucleus
Page 3 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Short Answer
26. What did Thucydides learn by observing the Athenian plague?
Answer
He saw that people who had been infected by the disease but recovered did not become infected
again when they came into contact with sick people. This shows an early understanding of the
concept of immunity.
27. Why was the invention of the microscope important for microbiology?
Answer
With a light microscope, scientists could finally see different kinds of microbes and observe their
characteristics.
28. What are some ways people use microbes?
Answer
People can use microbes to make fermented foods, to clean up the environment, and to prevent
and treat infectious diseases.
29. What is a phylogenetic tree?
Answer
A phylogenetic tree is a diagram showing how different organisms are thought to be
evolutionarily related.
30. Which of the five kingdoms in Whittaker’s phylogenetic tree are prokaryotic, and which are
eukaryotic?
Answer
Prokaryotic: Monera; Eukaryotic: Protista, Animalia, Fungi, Plantae
31. What molecule did Woese and Fox use to construct their phylogenetic tree?
Answer
small subunit rRNA
32. Name some techniques that can be used to identify and differentiate species of bacteria.
Answer
Gram staining, DNA/RNA analysis, biochemical assays, and serological testing
33. Describe the differences between bacteria and archaea.
Answer
Archaea and bacteria have different evolutionary histories, genes, metabolic pathways, cell
walls, and membrane lipids.
34. Name three structures that various protozoa use for locomotion.
Answer
They can use hair-like cilia, tail-like flagella, or pseudopods (“false feet”).
35. Describe the actual and relative sizes of a virus, a bacterium, and a plant or animal cell.
Answer
A virus is about 100 nm and is 10 times smaller than a bacterium (~1 µm), which is at least 10
times smaller than a plant or animal cell (10–100 µm).
Critical Thinking
36. Explain how the discovery of fermented foods likely benefited our ancestors.
Answer
Page 4 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Besides enhancing the taste of many foods, fermentation is one of the oldest methods of
preserving perishable foods. This means fermented foods lasted longer and were less likely to
spoil and cause illness.
37. What evidence would you use to support this statement: Ancient people thought that disease
was transmitted by things they could not see.
Answer
The Romans built sewer and water systems to protect against disease. The concept of
quarantining people with leprosy is found in the Bible. The Roman Marcus Terentius Varro
proposed that disease could be caused by “certain minute creatures . . . which cannot be seen by
the eye.”
38. Why is using binomial nomenclature more useful than using common names?
Answer
In binomial nomenclature, each organism has a unique name. Common names can vary between
different countries or even within a country. It can also be difficult to come up with common
names for very similar organisms.
39. Label the three Domains found on modern phylogenetic trees.
Answer
Bacteria (purple), Archaea (red), Eukarya (brown)
40. Contrast the behavior of a virus outside versus inside a cell.
Answer
Inside a host cell, viruses are able to reproduce. A virus is unable to reproduce when it is outside
of a cell.
41. Where would a virus, bacterium, animal cell, and a prion belong on this chart?
Page 5 of 7
,OpenStax Microbiology
Chapter 1: An Invisible World
Answer
Virus at ~100 nm, bacterium at ~1 μm, animal cell at between 10–100 µm. Since a prion is a
protein, it would be located at about 10 nm.
This file is copyright 2016, Rice University. All Rights Reserved.
Page 6 of 7
,OpenStax Microbiology
Chapter 2: How We See the Invisible World
OpenStax Microbiology
Chapter 2: How We See the Invisible World
Multiple Choice
1. Which of the following has the highest energy?
A. light with a long wavelength
B. light with an intermediate wavelength
C. light with a short wavelength
D. It is impossible to tell from the information given.
Answer
C
2. You place a specimen under the microscope and notice that parts of the specimen begin to emit light
immediately. These materials can be described as _____________.
A. fluorescent
B. phosphorescent
C. transparent
D. opaque
Answer
A
3. Who was the first to describe “cells” in dead cork tissue?
A. Hans Janssen
B. Zaccharias Janssen
C. Antonie van Leeuwenhoek
D. Robert Hooke
Answer
D
4. Who is the probable inventor of the compound microscope?
A. Girolamo Fracastoro
B. Zaccharias Janssen
C. Antonie van Leeuwenhoek
D. Robert Hooke
Answer
B
5. Which would be the best choice for viewing internal structures of a living protist such as a
Paramecium?
A. a brightfield microscope with a stain
B. a brightfield microscope without a stain
C. a darkfield microscope
D. a transmission electron microscope
Answer
C
6. Which type of microscope is especially useful for viewing thick structures such as biofilms?
A. a transmission electron microscope
B. a scanning electron microscopes
C. a phase-contrast microscope
D. a confocal scanning laser microscope
E. an atomic force microscope
Answer
Page 1 of 5
,OpenStax Microbiology
Chapter 2: How We See the Invisible World
D
7. Which type of microscope would be the best choice for viewing very small surface structures of a cell?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
B
8. What type of microscope uses an annular stop?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
E
9. What type of microscope uses a cone of light so that light only hits the specimen indirectly, producing
a light image on a dark background?
A. a transmission electron microscope
B. a scanning electron microscope
C. a brightfield microscope
D. a darkfield microscope
E. a phase-contrast microscope
Answer
D
10. What mordant is used in Gram staining?
A. crystal violet
B. safranin
C. acid-alcohol
D. iodine
Answer
D
11. What is one difference between specimen preparation for a transmission electron microscope
(TEM) and preparation for a scanning electron microscope (SEM)?
A. Only the TEM specimen requires sputter coating.
B. Only the SEM specimen requires sputter-coating.
C. Only the TEM specimen must be dehydrated.
D. Only the SEM specimen must be dehydrated.
Answer
B
Fill-in-the-Blank
12. When you see light bend as it moves from air into water, you are observing _________.
Answer
refraction
13. A microscope that uses multiple lenses is called a _________ microscope.
Page 2 of 5
, OpenStax Microbiology
Chapter 2: How We See the Invisible World
Answer
compound
14. Chromophores that absorb and then emit light are called __________.
Answer
fluorochromes
15. In a(n) _______ microscope, a probe located just above the specimen moves up and down in response
to forces between the atoms and the tip of the probe.
Answer
atomic force microscope
16. What is the total magnification of a specimen that is being viewed with a standard ocular lens and a
40× objective lens?
Answer
400×
17. Ziehl-Neelsen staining, a type of _______ staining, is diagnostic for Mycobacterium tuberculosis.
Answer
acid-fast
18. The _______ is used to differentiate bacterial cells based on the components of their cell walls.
Answer
Gram stain
Short Answer
19. Explain how a prism separates white light into different colors.
Answer
White light consists of light waves of many different frequencies. A prism is a material with different
refractive indices for light of different frequencies. Thus, when white light passes through the prism,
waves of different frequencies are refracted in different directions; this appears to the human eye as a
spectrum of colors similar to a rainbow.
20. Why is Antonie van Leeuwenhoek’s work much better known than that of Zaccharias Janssen?
Answer
Van Leeuwenhoek published and publicized his work.
21. Why did the cork cells observed by Robert Hooke appear to be empty, as opposed to being full of
other structures?
Answer
The cork cells were dead and the structures observed were the cell walls.
22. What is the function of the condenser in a brightfield microscope?
Answer
It focuses light from the light source onto the specimen.
23. How could you identify whether a particular bacterial sample contained specimens with mycolic acid-
rich cell walls?
Answer
Acid-fast staining should be used.
24. Label each component of the brightfield microscope.
Page 3 of 5
