Portage Microbiology Exam 4 Questions
and Answers Graded A+
True or False: Growth media is best suited for distinguishing between two similar
species of bacteria - Correct answer-False. Growth media is designed to simply
support (and not restrict) microbial growth
A researcher is asked to determine which of two vials contains e coli and which
contains salmonella. Knowing both gram-negative while only one of them is
capable of fermenting lactose, which type of media would be best suited (multiple
choice) - Correct answer-Differential media distinguishes between two, often
related, microbes
A researcher is asked to determine if a sample contains Neisseria meningitides.
Knowing Neisseria meningitides is slow growing and other foreign microbes may
also be present in the culture, which type of media would be best suited? (multiple
choice) - Correct answer-Selective media
What are the requirements of a fastidious microbe? (short answer) - Correct
answer-A fastidious microbe is an organism with complex growth requirements
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, such that is absent it will not grow. Enriched medias thus contain these specific and
essential nutrients required for the growth of a particular subset of microorganisms.
True or False: LB agar is classified as a selective, non-differential media - Correct
answer-False
What is agar used for in microbiology? (short answer) - Correct answer-Agar is
used to create a solid, smooth surface on which microbes can grow
Alpha hemolysis (matching) - Correct answer-Incomplete hemolytic activity
Beta hemolysis (matching) - Correct answer-Complete hemolytic activity
Gamma hemolysis (matching) - Correct answer-no hemolytic activity
Columbia CNA agar is most closely related to which media (multiple choice) -
Correct answer-blood agar
True or False: Chocolate agar gets its brown color from cocoa to produce an
enriched media - Correct answer-false
True or False: Chocolate is not a component of chocolate agar plates - Correct
answer-true
A researcher is studying a strain of e coli currently growing on a MacConkey plate.
However, the researcher can't remember if e coli is gram positive or gram negative.
Would a gram stain be necessary to confirm? Why or why not? (short answer) -
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and Answers Graded A+
True or False: Growth media is best suited for distinguishing between two similar
species of bacteria - Correct answer-False. Growth media is designed to simply
support (and not restrict) microbial growth
A researcher is asked to determine which of two vials contains e coli and which
contains salmonella. Knowing both gram-negative while only one of them is
capable of fermenting lactose, which type of media would be best suited (multiple
choice) - Correct answer-Differential media distinguishes between two, often
related, microbes
A researcher is asked to determine if a sample contains Neisseria meningitides.
Knowing Neisseria meningitides is slow growing and other foreign microbes may
also be present in the culture, which type of media would be best suited? (multiple
choice) - Correct answer-Selective media
What are the requirements of a fastidious microbe? (short answer) - Correct
answer-A fastidious microbe is an organism with complex growth requirements
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, such that is absent it will not grow. Enriched medias thus contain these specific and
essential nutrients required for the growth of a particular subset of microorganisms.
True or False: LB agar is classified as a selective, non-differential media - Correct
answer-False
What is agar used for in microbiology? (short answer) - Correct answer-Agar is
used to create a solid, smooth surface on which microbes can grow
Alpha hemolysis (matching) - Correct answer-Incomplete hemolytic activity
Beta hemolysis (matching) - Correct answer-Complete hemolytic activity
Gamma hemolysis (matching) - Correct answer-no hemolytic activity
Columbia CNA agar is most closely related to which media (multiple choice) -
Correct answer-blood agar
True or False: Chocolate agar gets its brown color from cocoa to produce an
enriched media - Correct answer-false
True or False: Chocolate is not a component of chocolate agar plates - Correct
answer-true
A researcher is studying a strain of e coli currently growing on a MacConkey plate.
However, the researcher can't remember if e coli is gram positive or gram negative.
Would a gram stain be necessary to confirm? Why or why not? (short answer) -
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
