© EVERLY 2025 ALL RIGHTS RESERVED.
TCU Microbiology Lab Exam 1 Questions
And Answers 100% Pass.
Chemically defined (synthetic) media - Answer✔media composed of precisely defined
chemicals
elements that all bacteria need - Answer✔carbon, nitrogen, phosphorus, sulfur, oxygen, and
hydrogen
minimal media - Answer✔media that contains exact nutrients needed for growth and nothing
extra
- media is useful b/c we know exactly what's in it, but few organisms are resourceful enough to
survive with only a few salts and sugars
complex media - Answer✔- it contains all the nutrients necessary for the microbes
- aka general purpose media, satisfies the nutritional requirements of bacteria with more stringent
growth requirements
- consists of mix of digests & extracts from plant or animal tissue
- nutrient rich but poorly defined with the exact nutrients unknown
- in lab we use complex media: tryptic soy media
enriched media - Answer✔complex media that contains additional "special" nutrients/additives
that are not commonly found in media
- least commonly used media
autoclave - Answer✔media is subjected to high-pressure steam at 121C at 15 lbs. of pressure to
sterilize and destroy any contaminants present
two major forms of media - Answer✔liquid and solid media
- media solidifies by adding agar (1.5%)
- agar is inert and incapable of growing by itself
what temperature do most bacterial organisms grow at? - Answer✔37C (98.6F)
colony - Answer✔A population of cells arising from a bacterial cell group or from a group of
attached bacterial cells
, © EVERLY 2025 ALL RIGHTS RESERVED.
colony forming units (cfu) - Answer✔estimate the approximate number of bacteria in a liquid
broth culture
simple microscope - Answer✔contains a single magnifying lens and is similar to a magnifying
lens
compound microscope - Answer✔consists of two singles lenses arranged one in front of the
other so that the second lens magnifies the image produced by the first
illuminator - Answer✔light emits from this
condenser - Answer✔light passes through this and concentrates the light and focuses the light
onto the specimen
parfocal - Answer✔property of a microscope which allows objectives to be changed with
minimal or no refocusing
total magnification - Answer✔objective magnification (4X, 10X, 40X, 100X) x ocular
magnification (10X)
working distance - Answer✔distance between the objective and the object being viewed
depth of focus - Answer✔thickness of specimen that can be seen in focus at one time
resolving power - Answer✔the ability of the microscope to distinguish between two closely
adjacent points; measured in distance units
refractive index - Answer✔measure of how much the speed of light is reduced inside a medium
such as glass; the refractive index of air and glass are different enough so that light waves change
direction when they cross the interface from air to glass. The necessitates that use of immersion
oil with our 100X oil-immersion oil.
aseptic technique - Answer✔transferring without causing contamination to the culture
- minimizes the chance of infection
pure culture - Answer✔a culture in which only one bacterial strain is present
What do you anticipate would occur if you forget the essential step of autoclaving when
preparing media? - Answer✔media would be contaminated
When flame-sterilizing a transfer loop, why must the transfer loop be heated from the handle-end
first? - Answer✔to avoid production of aerosols
What is the purpose of performing a streak plate? - Answer✔to isolate individual colonies
- to separate into different colonies throughout the plate
What property of our microscope allows the objectives to be changed with minimal refocusing
that we only use the fine focus adjustment when viewing with the 40x and 100x objectives? -
Answer✔Parfocal
TCU Microbiology Lab Exam 1 Questions
And Answers 100% Pass.
Chemically defined (synthetic) media - Answer✔media composed of precisely defined
chemicals
elements that all bacteria need - Answer✔carbon, nitrogen, phosphorus, sulfur, oxygen, and
hydrogen
minimal media - Answer✔media that contains exact nutrients needed for growth and nothing
extra
- media is useful b/c we know exactly what's in it, but few organisms are resourceful enough to
survive with only a few salts and sugars
complex media - Answer✔- it contains all the nutrients necessary for the microbes
- aka general purpose media, satisfies the nutritional requirements of bacteria with more stringent
growth requirements
- consists of mix of digests & extracts from plant or animal tissue
- nutrient rich but poorly defined with the exact nutrients unknown
- in lab we use complex media: tryptic soy media
enriched media - Answer✔complex media that contains additional "special" nutrients/additives
that are not commonly found in media
- least commonly used media
autoclave - Answer✔media is subjected to high-pressure steam at 121C at 15 lbs. of pressure to
sterilize and destroy any contaminants present
two major forms of media - Answer✔liquid and solid media
- media solidifies by adding agar (1.5%)
- agar is inert and incapable of growing by itself
what temperature do most bacterial organisms grow at? - Answer✔37C (98.6F)
colony - Answer✔A population of cells arising from a bacterial cell group or from a group of
attached bacterial cells
, © EVERLY 2025 ALL RIGHTS RESERVED.
colony forming units (cfu) - Answer✔estimate the approximate number of bacteria in a liquid
broth culture
simple microscope - Answer✔contains a single magnifying lens and is similar to a magnifying
lens
compound microscope - Answer✔consists of two singles lenses arranged one in front of the
other so that the second lens magnifies the image produced by the first
illuminator - Answer✔light emits from this
condenser - Answer✔light passes through this and concentrates the light and focuses the light
onto the specimen
parfocal - Answer✔property of a microscope which allows objectives to be changed with
minimal or no refocusing
total magnification - Answer✔objective magnification (4X, 10X, 40X, 100X) x ocular
magnification (10X)
working distance - Answer✔distance between the objective and the object being viewed
depth of focus - Answer✔thickness of specimen that can be seen in focus at one time
resolving power - Answer✔the ability of the microscope to distinguish between two closely
adjacent points; measured in distance units
refractive index - Answer✔measure of how much the speed of light is reduced inside a medium
such as glass; the refractive index of air and glass are different enough so that light waves change
direction when they cross the interface from air to glass. The necessitates that use of immersion
oil with our 100X oil-immersion oil.
aseptic technique - Answer✔transferring without causing contamination to the culture
- minimizes the chance of infection
pure culture - Answer✔a culture in which only one bacterial strain is present
What do you anticipate would occur if you forget the essential step of autoclaving when
preparing media? - Answer✔media would be contaminated
When flame-sterilizing a transfer loop, why must the transfer loop be heated from the handle-end
first? - Answer✔to avoid production of aerosols
What is the purpose of performing a streak plate? - Answer✔to isolate individual colonies
- to separate into different colonies throughout the plate
What property of our microscope allows the objectives to be changed with minimal refocusing
that we only use the fine focus adjustment when viewing with the 40x and 100x objectives? -
Answer✔Parfocal
