BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
What are the problems inherent in studying microorganisms Correct Ans-They are invisible
and widely distributed; they usually need to grow under controlled situations, in lab; strains
must be separated
There are ____ to microscopy Correct Ans-limits
Most major discoveries in microbiology are Correct Ans-not based on anything one can see
Many microbiologists never ___ Correct Ans-look in a microscope
Microscopy is no the most important part of Correct Ans-microbiology
How do you study microorganisms without a microscope? Correct Ans-make billions of
cells to study rather than one, but all the cells have to be exactly alike.
To get a pure culture, you need Correct Ans-culturing techniques, and aseptic technique
,BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
Pure cultures led to Correct Ans-the development of broths and, especially solid culture
media and techniques, sterilization, etc.
Koch's Postulate: 1 Correct Ans-The suspected pathogenic organism should be present in
all cases of the disease and absent from healthy animals
Koch's Postulate: 2 Correct Ans-The suspected organism should be grown in pure culture
Koch's Postulate: 3 Correct Ans-Cells from a pure culture of the suspected organism should
cause disease in healthy animal
Koch's Postulate: 4 Correct Ans-The organism should be reisolated and shown to be the
same as the original
Potential methodological difficulties for Postulate 1 Correct Ans-Personal safety;
difficulties in detection
Difficulties in disease detection Correct Ans-visibility, culturability, unknown life cycle
,BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
What % of bacteria do we not know how to grow? Correct Ans-90%
What animal do we use to grow a certain type of bacteria? Correct Ans-Armadillos
What does not prove that a certain bacteria caused a disease? Correct Ans-association
How does HIV work within the body? Correct Ans-it hides in the T-Helper cells in our
immune system
Why is the 2nd postulate necessary? Correct Ans-Non-pure culture would confound
interpretation
Potential methodological difficulties for Postulate 2 Correct Ans-not all microorganisms
can be cultured
Why is the 4th postulate necessary? Correct Ans-There may have been something else
introduced, or someone could've made a mistake; this makes it certain that someone causes
this.
, BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
What do you need for Koch's postulates to be met? Correct Ans-a pure culture
Culture Correct Ans-the observable growth in a medium
medium Correct Ans-a nutrient solution - solid, liquid, or semisolid - used to grow
microorganisms
Inoculation Correct Ans-verb pertaining to growth in a medium; intro of small sample into
a medium for growth
A colony is normally the product of only one or very few cells (T/F) Correct Ans-TRUE
How do we get a pure culture? Correct Ans-isolate cells
What are the problems inherent in studying microorganisms Correct Ans-They are invisible
and widely distributed; they usually need to grow under controlled situations, in lab; strains
must be separated
There are ____ to microscopy Correct Ans-limits
Most major discoveries in microbiology are Correct Ans-not based on anything one can see
Many microbiologists never ___ Correct Ans-look in a microscope
Microscopy is no the most important part of Correct Ans-microbiology
How do you study microorganisms without a microscope? Correct Ans-make billions of
cells to study rather than one, but all the cells have to be exactly alike.
To get a pure culture, you need Correct Ans-culturing techniques, and aseptic technique
,BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
Pure cultures led to Correct Ans-the development of broths and, especially solid culture
media and techniques, sterilization, etc.
Koch's Postulate: 1 Correct Ans-The suspected pathogenic organism should be present in
all cases of the disease and absent from healthy animals
Koch's Postulate: 2 Correct Ans-The suspected organism should be grown in pure culture
Koch's Postulate: 3 Correct Ans-Cells from a pure culture of the suspected organism should
cause disease in healthy animal
Koch's Postulate: 4 Correct Ans-The organism should be reisolated and shown to be the
same as the original
Potential methodological difficulties for Postulate 1 Correct Ans-Personal safety;
difficulties in detection
Difficulties in disease detection Correct Ans-visibility, culturability, unknown life cycle
,BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
What % of bacteria do we not know how to grow? Correct Ans-90%
What animal do we use to grow a certain type of bacteria? Correct Ans-Armadillos
What does not prove that a certain bacteria caused a disease? Correct Ans-association
How does HIV work within the body? Correct Ans-it hides in the T-Helper cells in our
immune system
Why is the 2nd postulate necessary? Correct Ans-Non-pure culture would confound
interpretation
Potential methodological difficulties for Postulate 2 Correct Ans-not all microorganisms
can be cultured
Why is the 4th postulate necessary? Correct Ans-There may have been something else
introduced, or someone could've made a mistake; this makes it certain that someone causes
this.
, BIO 280 Exam 2 Dr. Herrick JMU; Questions and Answers
What do you need for Koch's postulates to be met? Correct Ans-a pure culture
Culture Correct Ans-the observable growth in a medium
medium Correct Ans-a nutrient solution - solid, liquid, or semisolid - used to grow
microorganisms
Inoculation Correct Ans-verb pertaining to growth in a medium; intro of small sample into
a medium for growth
A colony is normally the product of only one or very few cells (T/F) Correct Ans-TRUE
How do we get a pure culture? Correct Ans-isolate cells
