UIUC MCB 100 EXAM 1 QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2025/2026
What is the approximate time that microscopes were invented? - Answers circa 1600s
When were microbes first discovered? - Answers Mid 1600s
True or false: Animal-associated microbes actually comprise only an insignificant fraction of the
global microbial population. - Answers True!
True or false: Harmful interactions are frequent relative to benign/beneficial relationships
between bacteria and humans. - Answers False: They are rare!
True or false: Not only are microbes responsible for the air we breathe and the ability to breathe
it, but they are actually responsible for supplying >50% of the world's oxygen through
photosynthesis by cyanobacteria and chlorophyll-containing phytoplankton. - Answers True
______________ is a process for experimentation that is used to conduct scientific inquiry. -
Answers Scientific method
When using the scientific method, we seek experimental evidence to test what we think which is
usually referred to as a __________ or _____________. - Answers hypothesis or model
Who (and when) was the first to observe microbes under a microscope? - Answers Antonie van
Leeuwenhoek (1676)
What did Antonie van Leeuwenhoek first call the microorganisms that he observed? - Answers
"Animalcules"
What leads to a hypothesis? - Answers Observations
______________ proposes that microorganisms are the cause of many diseases. - Answers Germ
Theory
Who (and when) proposed that epidemic diseases were caused by transferable tiny particles or
"tinder" that could transmit infection by contact? - Answers Girolamo Fracastoro (1545)
Who (and when) discovered that muscardine disease of silkworms was caused by living
parasitic organism (a fungus) and later proposed that human diseases were also caused by
living organisms? - Answers Agostino Bassi (1807)
Note: proposal of human disease causation in 1884
Who (and when) developed the concept of miasma, or "bad air," which was the early germ
theory that living organisms caused infectious diseases? - Answers Friedrich Henle (1840)
Name the three people that were known for the beginning of the Germ Theory of Disease. -
Answers Girolamo Fracastoro
, Agostino Bassi
Friedrich Henle
Name three scientists who were considered to make breakthroughs on Germ Theory of Disease.
- Answers Ignaz Semmelweis
John Snow
Louis Pasteur
Who (and when) made the connection between the lack of handwashing and child birth fever.
He tested the theory by making doctors wash their hands with chlorinated lime water which
reduced mortality from 18% to 2%? - Answers Ignaz Semmelweis (1847)
Who (and when) traced the source of a cholera outbreak in London to contaminated water
obtained from a particular well, which was the geographical center of the outbreak? - Answers
John Snow (1854)
Who conducted the first experiments demonstrating that fermentation and growth of microbes
in nutrient broth did not proceed by spontaneous generation or by miasma (two of the
predominant theories at the time)? - Answers Louis Pasteur
When was the process of pasteurization invented by Louis Pasteur? - Answers 1862
Define the Scientific Method. - Answers A process for experimentation that is used to conduct
scientific inquiry.
What is Germ Theory? - Answers A proposition that microorganisms are the cause of many
diseases.
__________________ is the ability to distinguish two points that are close together. The better it is,
the better two nearby objects are distinguished from one another. - Answers Resolution
(resolving power)
Note: Different types of microscopes have different resolving powers.
Do electron microscopes have high or low resolution? - Answers High resolution for small
volume of microbes
Do light microscopes have high or low resolution? - Answers low resolution
Name two positives and two negatives about electron microscopes. - Answers Positives: more
resolution, more magnification
Negatives: Cumbersome, black and white images
What is the approximate time that microscopes were invented? - Answers circa 1600s
When were microbes first discovered? - Answers Mid 1600s
True or false: Animal-associated microbes actually comprise only an insignificant fraction of the
global microbial population. - Answers True!
True or false: Harmful interactions are frequent relative to benign/beneficial relationships
between bacteria and humans. - Answers False: They are rare!
True or false: Not only are microbes responsible for the air we breathe and the ability to breathe
it, but they are actually responsible for supplying >50% of the world's oxygen through
photosynthesis by cyanobacteria and chlorophyll-containing phytoplankton. - Answers True
______________ is a process for experimentation that is used to conduct scientific inquiry. -
Answers Scientific method
When using the scientific method, we seek experimental evidence to test what we think which is
usually referred to as a __________ or _____________. - Answers hypothesis or model
Who (and when) was the first to observe microbes under a microscope? - Answers Antonie van
Leeuwenhoek (1676)
What did Antonie van Leeuwenhoek first call the microorganisms that he observed? - Answers
"Animalcules"
What leads to a hypothesis? - Answers Observations
______________ proposes that microorganisms are the cause of many diseases. - Answers Germ
Theory
Who (and when) proposed that epidemic diseases were caused by transferable tiny particles or
"tinder" that could transmit infection by contact? - Answers Girolamo Fracastoro (1545)
Who (and when) discovered that muscardine disease of silkworms was caused by living
parasitic organism (a fungus) and later proposed that human diseases were also caused by
living organisms? - Answers Agostino Bassi (1807)
Note: proposal of human disease causation in 1884
Who (and when) developed the concept of miasma, or "bad air," which was the early germ
theory that living organisms caused infectious diseases? - Answers Friedrich Henle (1840)
Name the three people that were known for the beginning of the Germ Theory of Disease. -
Answers Girolamo Fracastoro
, Agostino Bassi
Friedrich Henle
Name three scientists who were considered to make breakthroughs on Germ Theory of Disease.
- Answers Ignaz Semmelweis
John Snow
Louis Pasteur
Who (and when) made the connection between the lack of handwashing and child birth fever.
He tested the theory by making doctors wash their hands with chlorinated lime water which
reduced mortality from 18% to 2%? - Answers Ignaz Semmelweis (1847)
Who (and when) traced the source of a cholera outbreak in London to contaminated water
obtained from a particular well, which was the geographical center of the outbreak? - Answers
John Snow (1854)
Who conducted the first experiments demonstrating that fermentation and growth of microbes
in nutrient broth did not proceed by spontaneous generation or by miasma (two of the
predominant theories at the time)? - Answers Louis Pasteur
When was the process of pasteurization invented by Louis Pasteur? - Answers 1862
Define the Scientific Method. - Answers A process for experimentation that is used to conduct
scientific inquiry.
What is Germ Theory? - Answers A proposition that microorganisms are the cause of many
diseases.
__________________ is the ability to distinguish two points that are close together. The better it is,
the better two nearby objects are distinguished from one another. - Answers Resolution
(resolving power)
Note: Different types of microscopes have different resolving powers.
Do electron microscopes have high or low resolution? - Answers High resolution for small
volume of microbes
Do light microscopes have high or low resolution? - Answers low resolution
Name two positives and two negatives about electron microscopes. - Answers Positives: more
resolution, more magnification
Negatives: Cumbersome, black and white images
