Microbiology Lab - Exam 2 Questions
and Answers 100% Pass
medium - ✔✔a mixture of nutritional substances on or in which
microorganisms grow
autotroph - ✔✔nutritionally deficient mutants that have lost the ability to
synthesize a particular enzyme
many microorganisms in this group:
- can carry out photosynthesis
- usually do not cause disease
- synthesize organic compounds to obtain energy
heterotroph - ✔✔an organism that uses compounds to produce
biomolecules
1
100% Pass Guarantee Katelyn Whitman, All Rights
,autoclave - ✔✔an instrument for sterilization by means of moist heat under
pressure
Autoclaving combines ____ and ____ to destroy high resistant bacteria. -
✔✔high temp and high pressure
What are six basic nutritional requirements of every living thing? -
✔✔Water, carbon, nitrogen, metallic elements, energy and growth factors
such as vitamins
general purpose media - ✔✔Designed to grow a broad spectrum of
microbes that do not have special growth requirements
enriched media - ✔✔medium that contains special additives that could
promote certain metabolic activities. (ex. trypticase soy agar, blood agar,
yeast extract broth)
- especially used for fastidious bacteria
selective media - ✔✔is a nutrient that inhibits the growth of a certain type
of microorganisms (ex. Gram + bacteria) while permitting the growth of a
different type (in this example, Gram - )
2
100% Pass Guarantee Katelyn Whitman, All Rights
, differential media - ✔✔medium which will differentiate between bacteria
based on how they change the medium or their appearance on the medium
EMB and HE are both ____ and ____. - ✔✔selective and differential
EMB and HE are selective for ____ and differential for ____. - ✔✔selective
for gram-negative bacteria and differential for lactose fermenters.
What do lactose fermenters and nonfermenters look like on each media? -
✔✔- Organisms which quickly ferment lactose will give dark-green to
black colonies on this medium; these colonies have a metallic sheen (Ecoli)
- Organisms that are slow fermenters of lactose will give pink to maroon
colonies on this medium. Those organisms that cannot ferment lactose at
all give white (colorless) colonies on EMB agar (since nonfermenters of
lactose are often high pathogenic, this is a useful way to identify potential
pathogens)
What is Shigella associated with? - ✔✔a genus associated with bacillary
dysentery
3
100% Pass Guarantee Katelyn Whitman, All Rights
and Answers 100% Pass
medium - ✔✔a mixture of nutritional substances on or in which
microorganisms grow
autotroph - ✔✔nutritionally deficient mutants that have lost the ability to
synthesize a particular enzyme
many microorganisms in this group:
- can carry out photosynthesis
- usually do not cause disease
- synthesize organic compounds to obtain energy
heterotroph - ✔✔an organism that uses compounds to produce
biomolecules
1
100% Pass Guarantee Katelyn Whitman, All Rights
,autoclave - ✔✔an instrument for sterilization by means of moist heat under
pressure
Autoclaving combines ____ and ____ to destroy high resistant bacteria. -
✔✔high temp and high pressure
What are six basic nutritional requirements of every living thing? -
✔✔Water, carbon, nitrogen, metallic elements, energy and growth factors
such as vitamins
general purpose media - ✔✔Designed to grow a broad spectrum of
microbes that do not have special growth requirements
enriched media - ✔✔medium that contains special additives that could
promote certain metabolic activities. (ex. trypticase soy agar, blood agar,
yeast extract broth)
- especially used for fastidious bacteria
selective media - ✔✔is a nutrient that inhibits the growth of a certain type
of microorganisms (ex. Gram + bacteria) while permitting the growth of a
different type (in this example, Gram - )
2
100% Pass Guarantee Katelyn Whitman, All Rights
, differential media - ✔✔medium which will differentiate between bacteria
based on how they change the medium or their appearance on the medium
EMB and HE are both ____ and ____. - ✔✔selective and differential
EMB and HE are selective for ____ and differential for ____. - ✔✔selective
for gram-negative bacteria and differential for lactose fermenters.
What do lactose fermenters and nonfermenters look like on each media? -
✔✔- Organisms which quickly ferment lactose will give dark-green to
black colonies on this medium; these colonies have a metallic sheen (Ecoli)
- Organisms that are slow fermenters of lactose will give pink to maroon
colonies on this medium. Those organisms that cannot ferment lactose at
all give white (colorless) colonies on EMB agar (since nonfermenters of
lactose are often high pathogenic, this is a useful way to identify potential
pathogens)
What is Shigella associated with? - ✔✔a genus associated with bacillary
dysentery
3
100% Pass Guarantee Katelyn Whitman, All Rights
