©THEBRIGHT 2024
MICR 221 Midterm Exam Questions With
Correct Answers
Example of Infectious Disease in 1813 and now - answer✔✔1813: Napoleon's army in Leipzig
had 220,000 out of 500,000 infected with illness like typhus and dysentery which led to his
defeat
Now: Haiti is in its 6th year of cholera that killed 10,000 and sickened 650,000
Who is Anton van Leeuwenhoek (1632-1723) and what is he credited for? - answer✔✔is a
haberdasher who is the first to describe microbes using microscopes that could magnify 50-300x;
discovered spermatozoa and red blood cells; wee animacules
What's the conflict with Anton and Robert Hooke? - answer✔✔Hooke might have been
overlooked since he was the first to draw and publish a microorganism but Anton was the first to
see it. Anton was Dutch and only spoke and wrote in Dutch which no one understood so his
discoveries went unnoticed until his work was translated
Describe Anton's Microscopes - answer✔✔he never shared his lenses and he ground them on his
own. you hold the microscope up to your eye and let the light come through so you could
examine it
What is Spontaneous Generation? - answer✔✔living organisms could develop from nonliving
matter
What did Aristotle and Helmont think of spontaneous generation? - answer✔✔A: thought that
simple invertebrates like toads or snakes could arise from putrid water
H: placed dirty rages with cheese in the middle and mice will arise
Describe Redi's experiments - answer✔✔placed meat on 3 containers: one uncovered, one
covered with cork, and one covered with a fine gauze
1st one: flies laid eggs on uncooked meat and produced maggots
2nd one: no maggots on meat
3rd: flies landed on gauze and laid eggs = maggots
, ©THEBRIGHT 2024
Result: generation of maggots on meat was by fly eggs
Describe Spallanzani's experiments - answer✔✔had sealed glass flasks containing beef broth
boiled for an hour and he sealed it to make it sterile. As long as the flasks were sealed, no growth
took place. He proposed that the air carried germs to culture medium but the external air might
be required for growth of animals already in the medium
Describe Pouchet's experiments - answer✔✔claimed to carry out experiments proving that
microbial growth could occur without air contamination
Describe Pasteur's cotton experiment - answer✔✔filtered air through cotton and found that
objects resembling plant spores were trapped and when he placed the cotton in a sterile medium,
microbial growth occurred
Describe Pasteur's beef broth experiment - answer✔✔placed nutrient solutions in flasks and
heated their necks and drew them out into a variety of curves while keeping the ends of the necks
open to air. no growth occurred even though the flasks were exposed to air because the dust and
germs were trapped on the curved necks. but if the swan neck was broken, air could get in along
with dust particles and the flask was not sterile. he basically resolved the controversy of
spontaneous generation, and showed how to keep solutions sterile
Bubonic Plague - answer✔✔first use of quarantine.
Ancient people knew about contagious diseases (EXAMPLE: leprosy: if you have it, you were
shunned and had to live on the outskirts away from people).
One third of European population was killed (25 million) and eventually about 80% of the
population was killed. Some believe it was the first use of germ warfare (accounts of cities under
siege and opposing city would catapult bodies with the disease over city walls)
What did Typhoid Mary do and when was her reign of terror? - answer✔✔1901-1938. She was
working as a cook when she was exposed to typhoid. She infects multiple people and always
leaves. The police put her in a hospital and they wanted to remove her gallbladder in order to
remove the typhoid but she refuses because she is scared of surgery. She eventually dies from a
stroke.
What did Fracastoro suggest and believe? What did he discover first? Year? - answer✔✔He
suggested that invisible organisms produced disease and believed that disease was due to
supernatural forces, poisonous vapours called miasmas and imbalances among the four humours
were thought to be present in the body. Syphilis; and suggested a possible transmission for
sexual contact. 1530.
What did Semmelweis discover and how did he die? - answer✔✔1850. Found that puerperal
fever was caused by a doctor that didn't wash their hands after examining dead bodies in the
morgue (especially bad for women giving birth - 15% of women would die because of this). If
, ©THEBRIGHT 2024
you were in a ward that had midwives they was a 4x more chance of you surviving. He instituted
a hand-washing policy with a lime chloride solution: results = 12% deaths to over 1% deaths.
Doctors didn't like him; they harassed him; he lost his job and went insane. He dies from S.
pyogenes infection (same organism that causes puerperal fever).
Who is Joseph Lister and what is now named after him? - answer✔✔1864. He thought that
infections after surgery were caused by organisms in the air or surgical instruments. By now,
anesthetics were introduced which meant that complicated surgeries were performed and the
patient would survive but die after in post-op. So he sterilized his instruments and performed
surgeries in a cloud of disinfectant. The results were amazing and there was a much decreased
chance of getting sepsis afterwards. He concluded that microbes in the air and instruments led to
sepsis. Listerine.
What did Robert Koch do and how? - answer✔✔He established a relationship between Bacillus
anthraces and anthrax which is a bioterrorism threat. He worked with it in his own house. He
took the blood of an infected animal that was teeming with B. anthraces and injected it into a
healthy animal. He saw that the healthy animal was now infected with B. anthraces. He took a
pure inoculated culture and the healthy animal was still infected.
What are Koch's Postulates? - answer✔✔1. Microorganism must be present in every case of the
disease but absent from healthy organisms
2. suspected microorganisms must be isolated and grown in a pure culture
3. same disease must result when the isolated microorganism is inoculated into a healthy host
4. same microorganism must be isolated again from the diseased host
What's the controversy between Henle and Koch? - answer✔✔Both made the same postulates
but Koch did the experimental work that supported these postulates.
How did Koch use gelatine and potatoes and why did he use them? - answer✔✔He was trying to
isolate colonies so he used slices of boiled potatoes and a sterile pin to streak with but it didn't
work so he used gelatine which kind of worked but the problem was that when it was incubated
at 37 C it liquified.
Fannie and Walther Hesse suggested what? - answer✔✔the use of agar as a solidifying agent
since it isn't attacked by most bacteria and doesn't melt until reaching a temperature of 100 C.
Once melted, it didn't solidify until it reached 50 C, eliminating the need to handle boiling liquid
and providing time to manipulate the medium.
What did Richard Petri develop? - answer✔✔Petri dish as a container for holding solidified
media
MICR 221 Midterm Exam Questions With
Correct Answers
Example of Infectious Disease in 1813 and now - answer✔✔1813: Napoleon's army in Leipzig
had 220,000 out of 500,000 infected with illness like typhus and dysentery which led to his
defeat
Now: Haiti is in its 6th year of cholera that killed 10,000 and sickened 650,000
Who is Anton van Leeuwenhoek (1632-1723) and what is he credited for? - answer✔✔is a
haberdasher who is the first to describe microbes using microscopes that could magnify 50-300x;
discovered spermatozoa and red blood cells; wee animacules
What's the conflict with Anton and Robert Hooke? - answer✔✔Hooke might have been
overlooked since he was the first to draw and publish a microorganism but Anton was the first to
see it. Anton was Dutch and only spoke and wrote in Dutch which no one understood so his
discoveries went unnoticed until his work was translated
Describe Anton's Microscopes - answer✔✔he never shared his lenses and he ground them on his
own. you hold the microscope up to your eye and let the light come through so you could
examine it
What is Spontaneous Generation? - answer✔✔living organisms could develop from nonliving
matter
What did Aristotle and Helmont think of spontaneous generation? - answer✔✔A: thought that
simple invertebrates like toads or snakes could arise from putrid water
H: placed dirty rages with cheese in the middle and mice will arise
Describe Redi's experiments - answer✔✔placed meat on 3 containers: one uncovered, one
covered with cork, and one covered with a fine gauze
1st one: flies laid eggs on uncooked meat and produced maggots
2nd one: no maggots on meat
3rd: flies landed on gauze and laid eggs = maggots
, ©THEBRIGHT 2024
Result: generation of maggots on meat was by fly eggs
Describe Spallanzani's experiments - answer✔✔had sealed glass flasks containing beef broth
boiled for an hour and he sealed it to make it sterile. As long as the flasks were sealed, no growth
took place. He proposed that the air carried germs to culture medium but the external air might
be required for growth of animals already in the medium
Describe Pouchet's experiments - answer✔✔claimed to carry out experiments proving that
microbial growth could occur without air contamination
Describe Pasteur's cotton experiment - answer✔✔filtered air through cotton and found that
objects resembling plant spores were trapped and when he placed the cotton in a sterile medium,
microbial growth occurred
Describe Pasteur's beef broth experiment - answer✔✔placed nutrient solutions in flasks and
heated their necks and drew them out into a variety of curves while keeping the ends of the necks
open to air. no growth occurred even though the flasks were exposed to air because the dust and
germs were trapped on the curved necks. but if the swan neck was broken, air could get in along
with dust particles and the flask was not sterile. he basically resolved the controversy of
spontaneous generation, and showed how to keep solutions sterile
Bubonic Plague - answer✔✔first use of quarantine.
Ancient people knew about contagious diseases (EXAMPLE: leprosy: if you have it, you were
shunned and had to live on the outskirts away from people).
One third of European population was killed (25 million) and eventually about 80% of the
population was killed. Some believe it was the first use of germ warfare (accounts of cities under
siege and opposing city would catapult bodies with the disease over city walls)
What did Typhoid Mary do and when was her reign of terror? - answer✔✔1901-1938. She was
working as a cook when she was exposed to typhoid. She infects multiple people and always
leaves. The police put her in a hospital and they wanted to remove her gallbladder in order to
remove the typhoid but she refuses because she is scared of surgery. She eventually dies from a
stroke.
What did Fracastoro suggest and believe? What did he discover first? Year? - answer✔✔He
suggested that invisible organisms produced disease and believed that disease was due to
supernatural forces, poisonous vapours called miasmas and imbalances among the four humours
were thought to be present in the body. Syphilis; and suggested a possible transmission for
sexual contact. 1530.
What did Semmelweis discover and how did he die? - answer✔✔1850. Found that puerperal
fever was caused by a doctor that didn't wash their hands after examining dead bodies in the
morgue (especially bad for women giving birth - 15% of women would die because of this). If
, ©THEBRIGHT 2024
you were in a ward that had midwives they was a 4x more chance of you surviving. He instituted
a hand-washing policy with a lime chloride solution: results = 12% deaths to over 1% deaths.
Doctors didn't like him; they harassed him; he lost his job and went insane. He dies from S.
pyogenes infection (same organism that causes puerperal fever).
Who is Joseph Lister and what is now named after him? - answer✔✔1864. He thought that
infections after surgery were caused by organisms in the air or surgical instruments. By now,
anesthetics were introduced which meant that complicated surgeries were performed and the
patient would survive but die after in post-op. So he sterilized his instruments and performed
surgeries in a cloud of disinfectant. The results were amazing and there was a much decreased
chance of getting sepsis afterwards. He concluded that microbes in the air and instruments led to
sepsis. Listerine.
What did Robert Koch do and how? - answer✔✔He established a relationship between Bacillus
anthraces and anthrax which is a bioterrorism threat. He worked with it in his own house. He
took the blood of an infected animal that was teeming with B. anthraces and injected it into a
healthy animal. He saw that the healthy animal was now infected with B. anthraces. He took a
pure inoculated culture and the healthy animal was still infected.
What are Koch's Postulates? - answer✔✔1. Microorganism must be present in every case of the
disease but absent from healthy organisms
2. suspected microorganisms must be isolated and grown in a pure culture
3. same disease must result when the isolated microorganism is inoculated into a healthy host
4. same microorganism must be isolated again from the diseased host
What's the controversy between Henle and Koch? - answer✔✔Both made the same postulates
but Koch did the experimental work that supported these postulates.
How did Koch use gelatine and potatoes and why did he use them? - answer✔✔He was trying to
isolate colonies so he used slices of boiled potatoes and a sterile pin to streak with but it didn't
work so he used gelatine which kind of worked but the problem was that when it was incubated
at 37 C it liquified.
Fannie and Walther Hesse suggested what? - answer✔✔the use of agar as a solidifying agent
since it isn't attacked by most bacteria and doesn't melt until reaching a temperature of 100 C.
Once melted, it didn't solidify until it reached 50 C, eliminating the need to handle boiling liquid
and providing time to manipulate the medium.
What did Richard Petri develop? - answer✔✔Petri dish as a container for holding solidified
media
