INSTRUCTOR’S SOLUTIONS MANUAL
MICROBIOLOGY WITH DISEASES BY BODY SYSTEM
6TH EDITION
CHAPTER NO. 01: A BRIEF HISTORY OF MICROBIOLOGY
END OF CHAPTER ANSWERS
Multiple Choice
1. a 3. d 5. c 7. a 9. d
2. c 4. a 6. d 8. b 10. d
Fill in the Blanks
1. Martinus Beijerinck and Sergei Winogradsky
2. Louis Pasteur and Eduard Buchner
3. Paul Ehrlich
4. Edward Jenner
5. John Snow
6. Robert Koch
7. John Snow
8. Louis Pasteur
9. Louis Pasteur
Matching
1. J 4. C, H, K 7. C, D 10. D
2. H 5. B 8. E 11. I
3. M 6. A 9. D 12. L
Visualize It!
1. 1. cilium; 2. flagellum; 3. pseudopod; 4. nucleus
2. Microbes were only in the dust in the lowest portion of the swan-necked tube.
Short Answer
,1. The theory of spontaneous generation hindered the development of the field of
microbiology because the theory seemed to explain observed phenomena such as food
spoilage, so further investigations were not made. Leeuwenhoek’s microscopic
observations revealed previously unseen microorganisms and advanced interest in
microbiology.
2. Spallanzani’s flasks contained sterilized nutrients but were sealed from air, whereas
Pasteur’s had sterilized nutrients in flasks with curves (“swan-necked” flasks), which
allowed air to enter but trapped microorganisms that fell in the tube. Although
Pasteur’s controlled investigation provided all the environmental and nutritional
requirements for life to arise spontaneously, the flasks remained sterile. This settled
the dispute.
3. Six types of microorganisms: archaea, bacteria, protozoa, fungi, algae, and worms.
4. Leeuwenhoek’s investigations changed the world by revealing the presence of
microorganisms. Subsequent investigations were directed at microorganisms:, their
taxonomy, their effect on disease, disease control, and so on; and the result not only is
of academic interest but also affects the quality and duration of human life.
5. Macroscopic tapeworms are studied in microbiology because their eggs and infective
stages are microscopic and because of historical tradition.
6. “The Golden Age of Microbiology” was a 50-year period during which scientists
searched for the answers to four questions: (1) Is spontaneous generation of microbial
life possible? (2) What causes fermentation? (3) What causes disease? (4) How can
we prevent infections and disease? Applying the scientific method to their
investigations, biologists pioneered discoveries in disciplines such as industrial
microbiology, genetics, environmental microbiology, antiseptic medical technology,
serology, immunology, and chemotherapy. The season of discovery was “golden” to
the field of microbiology.
7. Today, microbiological investigations are propelled by four major questions: (1)
What are the basic chemical reactions of life? (2) How do genes work? (3) What roles
do microorganisms play in the environment? (4) How do we defend against disease?
8. Pasteur’s fermentation experiments followed the scientific method. (1) Pasteur
observed Needham’s investigations and questioned the source of microorganisms. (2)
He hypothesized that dust in the air contained microbes that would reproduce in
nutrient broth. (3) His experimental design (with controls) included heated infusion in
“swan-necked flasks,” which remained free of dust and therefore microbes unless the
flasks were tilted to allow the infusion to touch the dust in the curve of the flask.
Those flasks that were tilted showed microbial life. (4) Based on the results, Pasteur
concluded that microbes in the infusion were not spontaneous but rather were
descendants of microbes in the air or on dust particles.
9. Koch’s postulates are: (1) The suspected causative agent must be found in every case
of the disease and be absent from healthy hosts. (2) The agent must be isolated and
grown outside the host. (3) When the agent is introduced to a healthy, susceptible
host, the host must get the disease. (4) The same agent must be re-isolated from the
, diseased experimental host. These postulates are significant because when they are
satisfied, the cause of an infectious disease is proven.
10. HAI is an acronym for health care–associated infections (formerly called nosocomial
infections). These terms refer to infections acquired in a health care setting. Their
frequency emphasizes the need for good hygiene in health care facilities.
Critical Thinking
1. Koch would have been extremely frustrated by attempts to identify the agents of viral
diseases. Methods to detect viruses did not exist, and the means to grow viruses in the
laboratory had not been developed. His initial success with anthrax provided the basis
for the development of his postulates, for the bacteriologic methodology his
laboratory devised, and for his renown. Had Koch pursued viral diseases, his lifetime
accomplishments would have been greatly reduced: fewer etiologic agents would
have been identified, and doubt would have been cast on the power of his postulates.
2. Under the influence of Pasteur’s and Koch’s work, the Germ Theory of Disease had
become widely accepted in the early 1900s, and the prevailing belief in the scientific
community was that microorganisms caused all diseases. In this atmosphere,
explanations for disease that did not involve microbial infection were ridiculed.
Biochemistry was a very young science, and metabolism was just beginning to be
investigated. Although Funk’s interpretation of his observations was correct, he could
not provide a mechanism for how polished rice might promote disease.
3. Checking for the presence of H. influenzae in a large number of diagnosed cases of
flu would likely have cast doubt on the conclusion that H. influenzae was the cause of
flu. In some cases, H. influenzae is not present, and thus Koch’s first postulate would
not be satisfied. In addition, H. influenzae can be found in the upper respiratory tract
of people who do not have flu, inconsistent with the first postulate. Furthermore,
inoculation of H. influenzae into an experimental organism would not have produced
flu, violating the third postulate.
4. The relatively low temperature used in pasteurization is not high enough, nor is
heating long enough in duration to destroy bacterial endospores or fungal spores. Any
such contaminants would have a chance to germinate and ferment the milk over
winter break.
5. Pour the milk into sterile containers through a filter that will trap bacteria,
endospores, and spores, and then incubate in a sterile chamber or in a chamber with
filtered vents that allow air exchange but no microbial entry. If the sterile milk
remains sterile, then spontaneous generation did not occur.
6. Identifying cholera cases in persons who visited the Broad Street area only during the
day would demonstrate that nocturnal exposure to “fermented vapors” was not the
source of cholera.
7. Redi showed that flies laid eggs that hatched onto larvae on meat by covering jars of
meat with gauze upon which the events took place. Needham’s experiments with
boiled infusions and gravy in sealed containers suggested that microbes arise
, spontaneously, but Spallanzani repeated Needham’s experiments more rigorously and
concluded that spontaneous generation of microorganisms does not occur. The
absence of air exchange in Spallanzani’s experiments caused some doubt about his
conclusions. Pasteur demonstrated the growth of microorganisms in supposedly
sterile infusions in swan-necked flasks, which remained sterile unless contaminated
with nonsterile dust.
8. There are a number of possible answers, including infection control (hygiene and the
control of disease in health care settings), bioremediation (the use of microbes to
remove pollutants), pharmaceuticals (design and development of medications for
infectious disease), clinical microbiology (testing for microbes and their products in
the clinical setting), and recombinant DNA technology (the alteration of microbial
genes to synthesize useful products).
9. Algae have simple nutritional requirements (carbon dioxide, water, light, a few salts)
that are easily obtained from the environment; therefore, they do not need to obtain
nutrients from other living things.
10. Buchner’s experiments demonstrated that intact living cells were not required for
fermentation of sugars. Had the experiments been done in the 1850s, prior to
Pasteur’s experiments on spontaneous generation, one argument for spontaneous
generation (the appearance of yeast cells in fermenting sugar solutions) would have
been weakened. Spallanzani’s results might have been more widely accepted as
demonstrating that spontaneous generation does not occur. When scientists accepted
that animals do not arise from spontaneous generation, they might have been less
likely to exempt microorganisms.
11. Many bacteria are very small and may be easily overlooked during examination with
a light microscope. In contrast, Koch’s method allows a single microbe to reproduce
into a much more visible population of cells—a colony—which is less likely to be
overlooked. In addition, many microorganisms, especially pathogens, have stringent
nutritional requirements; dilution in standard growth medium might be harmful to the
microbes and therefore prevent their detection.
12. Koch’s postulates are not useful in determining the cause of diseases that are not
infections (e.g., Down syndrome, lung cancer). Some diseases (e.g., cholera) occur
only under specific conditions (high numbers, specific genetic component), so the
microbes may be present in asymptomatic persons, and Koch’s first postulate is not
met. Disease caused by microorganisms that are infectious only in humans is difficult
to prove by Koch’s postulates because ethical considerations prohibit deliberate
exposure of humans to potential harm (e.g., HIV/AIDS), preventing the third
postulate from being applied. Some syndromes are common to a variety of microbes
(e.g., pneumonia), so identifying a single causative agent is not possible (first
postulate again). Alzheimer disease may be a physiologic/genetic disorder and not
suitable for the application of Koch’s postulates, or it may be a syndrome caused by a
nonliving agent (prion), which also precludes application of the postulates.
MICROBIOLOGY WITH DISEASES BY BODY SYSTEM
6TH EDITION
CHAPTER NO. 01: A BRIEF HISTORY OF MICROBIOLOGY
END OF CHAPTER ANSWERS
Multiple Choice
1. a 3. d 5. c 7. a 9. d
2. c 4. a 6. d 8. b 10. d
Fill in the Blanks
1. Martinus Beijerinck and Sergei Winogradsky
2. Louis Pasteur and Eduard Buchner
3. Paul Ehrlich
4. Edward Jenner
5. John Snow
6. Robert Koch
7. John Snow
8. Louis Pasteur
9. Louis Pasteur
Matching
1. J 4. C, H, K 7. C, D 10. D
2. H 5. B 8. E 11. I
3. M 6. A 9. D 12. L
Visualize It!
1. 1. cilium; 2. flagellum; 3. pseudopod; 4. nucleus
2. Microbes were only in the dust in the lowest portion of the swan-necked tube.
Short Answer
,1. The theory of spontaneous generation hindered the development of the field of
microbiology because the theory seemed to explain observed phenomena such as food
spoilage, so further investigations were not made. Leeuwenhoek’s microscopic
observations revealed previously unseen microorganisms and advanced interest in
microbiology.
2. Spallanzani’s flasks contained sterilized nutrients but were sealed from air, whereas
Pasteur’s had sterilized nutrients in flasks with curves (“swan-necked” flasks), which
allowed air to enter but trapped microorganisms that fell in the tube. Although
Pasteur’s controlled investigation provided all the environmental and nutritional
requirements for life to arise spontaneously, the flasks remained sterile. This settled
the dispute.
3. Six types of microorganisms: archaea, bacteria, protozoa, fungi, algae, and worms.
4. Leeuwenhoek’s investigations changed the world by revealing the presence of
microorganisms. Subsequent investigations were directed at microorganisms:, their
taxonomy, their effect on disease, disease control, and so on; and the result not only is
of academic interest but also affects the quality and duration of human life.
5. Macroscopic tapeworms are studied in microbiology because their eggs and infective
stages are microscopic and because of historical tradition.
6. “The Golden Age of Microbiology” was a 50-year period during which scientists
searched for the answers to four questions: (1) Is spontaneous generation of microbial
life possible? (2) What causes fermentation? (3) What causes disease? (4) How can
we prevent infections and disease? Applying the scientific method to their
investigations, biologists pioneered discoveries in disciplines such as industrial
microbiology, genetics, environmental microbiology, antiseptic medical technology,
serology, immunology, and chemotherapy. The season of discovery was “golden” to
the field of microbiology.
7. Today, microbiological investigations are propelled by four major questions: (1)
What are the basic chemical reactions of life? (2) How do genes work? (3) What roles
do microorganisms play in the environment? (4) How do we defend against disease?
8. Pasteur’s fermentation experiments followed the scientific method. (1) Pasteur
observed Needham’s investigations and questioned the source of microorganisms. (2)
He hypothesized that dust in the air contained microbes that would reproduce in
nutrient broth. (3) His experimental design (with controls) included heated infusion in
“swan-necked flasks,” which remained free of dust and therefore microbes unless the
flasks were tilted to allow the infusion to touch the dust in the curve of the flask.
Those flasks that were tilted showed microbial life. (4) Based on the results, Pasteur
concluded that microbes in the infusion were not spontaneous but rather were
descendants of microbes in the air or on dust particles.
9. Koch’s postulates are: (1) The suspected causative agent must be found in every case
of the disease and be absent from healthy hosts. (2) The agent must be isolated and
grown outside the host. (3) When the agent is introduced to a healthy, susceptible
host, the host must get the disease. (4) The same agent must be re-isolated from the
, diseased experimental host. These postulates are significant because when they are
satisfied, the cause of an infectious disease is proven.
10. HAI is an acronym for health care–associated infections (formerly called nosocomial
infections). These terms refer to infections acquired in a health care setting. Their
frequency emphasizes the need for good hygiene in health care facilities.
Critical Thinking
1. Koch would have been extremely frustrated by attempts to identify the agents of viral
diseases. Methods to detect viruses did not exist, and the means to grow viruses in the
laboratory had not been developed. His initial success with anthrax provided the basis
for the development of his postulates, for the bacteriologic methodology his
laboratory devised, and for his renown. Had Koch pursued viral diseases, his lifetime
accomplishments would have been greatly reduced: fewer etiologic agents would
have been identified, and doubt would have been cast on the power of his postulates.
2. Under the influence of Pasteur’s and Koch’s work, the Germ Theory of Disease had
become widely accepted in the early 1900s, and the prevailing belief in the scientific
community was that microorganisms caused all diseases. In this atmosphere,
explanations for disease that did not involve microbial infection were ridiculed.
Biochemistry was a very young science, and metabolism was just beginning to be
investigated. Although Funk’s interpretation of his observations was correct, he could
not provide a mechanism for how polished rice might promote disease.
3. Checking for the presence of H. influenzae in a large number of diagnosed cases of
flu would likely have cast doubt on the conclusion that H. influenzae was the cause of
flu. In some cases, H. influenzae is not present, and thus Koch’s first postulate would
not be satisfied. In addition, H. influenzae can be found in the upper respiratory tract
of people who do not have flu, inconsistent with the first postulate. Furthermore,
inoculation of H. influenzae into an experimental organism would not have produced
flu, violating the third postulate.
4. The relatively low temperature used in pasteurization is not high enough, nor is
heating long enough in duration to destroy bacterial endospores or fungal spores. Any
such contaminants would have a chance to germinate and ferment the milk over
winter break.
5. Pour the milk into sterile containers through a filter that will trap bacteria,
endospores, and spores, and then incubate in a sterile chamber or in a chamber with
filtered vents that allow air exchange but no microbial entry. If the sterile milk
remains sterile, then spontaneous generation did not occur.
6. Identifying cholera cases in persons who visited the Broad Street area only during the
day would demonstrate that nocturnal exposure to “fermented vapors” was not the
source of cholera.
7. Redi showed that flies laid eggs that hatched onto larvae on meat by covering jars of
meat with gauze upon which the events took place. Needham’s experiments with
boiled infusions and gravy in sealed containers suggested that microbes arise
, spontaneously, but Spallanzani repeated Needham’s experiments more rigorously and
concluded that spontaneous generation of microorganisms does not occur. The
absence of air exchange in Spallanzani’s experiments caused some doubt about his
conclusions. Pasteur demonstrated the growth of microorganisms in supposedly
sterile infusions in swan-necked flasks, which remained sterile unless contaminated
with nonsterile dust.
8. There are a number of possible answers, including infection control (hygiene and the
control of disease in health care settings), bioremediation (the use of microbes to
remove pollutants), pharmaceuticals (design and development of medications for
infectious disease), clinical microbiology (testing for microbes and their products in
the clinical setting), and recombinant DNA technology (the alteration of microbial
genes to synthesize useful products).
9. Algae have simple nutritional requirements (carbon dioxide, water, light, a few salts)
that are easily obtained from the environment; therefore, they do not need to obtain
nutrients from other living things.
10. Buchner’s experiments demonstrated that intact living cells were not required for
fermentation of sugars. Had the experiments been done in the 1850s, prior to
Pasteur’s experiments on spontaneous generation, one argument for spontaneous
generation (the appearance of yeast cells in fermenting sugar solutions) would have
been weakened. Spallanzani’s results might have been more widely accepted as
demonstrating that spontaneous generation does not occur. When scientists accepted
that animals do not arise from spontaneous generation, they might have been less
likely to exempt microorganisms.
11. Many bacteria are very small and may be easily overlooked during examination with
a light microscope. In contrast, Koch’s method allows a single microbe to reproduce
into a much more visible population of cells—a colony—which is less likely to be
overlooked. In addition, many microorganisms, especially pathogens, have stringent
nutritional requirements; dilution in standard growth medium might be harmful to the
microbes and therefore prevent their detection.
12. Koch’s postulates are not useful in determining the cause of diseases that are not
infections (e.g., Down syndrome, lung cancer). Some diseases (e.g., cholera) occur
only under specific conditions (high numbers, specific genetic component), so the
microbes may be present in asymptomatic persons, and Koch’s first postulate is not
met. Disease caused by microorganisms that are infectious only in humans is difficult
to prove by Koch’s postulates because ethical considerations prohibit deliberate
exposure of humans to potential harm (e.g., HIV/AIDS), preventing the third
postulate from being applied. Some syndromes are common to a variety of microbes
(e.g., pneumonia), so identifying a single causative agent is not possible (first
postulate again). Alzheimer disease may be a physiologic/genetic disorder and not
suitable for the application of Koch’s postulates, or it may be a syndrome caused by a
nonliving agent (prion), which also precludes application of the postulates.
