UTA Microbiology Exam 2 Questions and Answers
Already Passed
4 Basic Steps of binary fission - ANSWER 1. Growth of cell size
2. Replication of DNA
3. Division of cytoplasm
4. Septum formation & cell division
Z Ring Assembly - ANSWER FtsZ assembles Z ring to form divisome
Generation Time - ANSWER time it takes to double the population
Lag Phase - ANSWER Cells adjust to culture medium; no change in population
What factors determine the duration of the lag phase? - ANSWER Genetic
makeup, media composition, initial inoculum size
During which phase of the growth curve is it most appropriate for the use of
antibiotics? - ANSWER Log phase
Following the death phase of the growth curve, ____ cells are considered the
surviving cells & are considered clinically important due to their association with
chronic infections, such as Tuberculosis. - ANSWER Persisters
Log Phase - ANSWER Binary fission occurs; cell replication > cell death
Stationary Phase - ANSWER Resources become depleted; cell respiration=cell
death
Death Phase - ANSWER Endospores can form; cell replication < cell death
Close System Cultures - ANSWER Have finite resources
Open System Cultures - ANSWER -Nutrients and air are replenished
-Dead cells and waste are removed
-Beneficial for industrial microbiology
Microscopic Cell Count - ANSWER Cells are counted under a microscope using a
laser etched slide
In using the direct microscopic cell count method, you will be able to distinguish
between live vs dead cells. - ANSWER False
Fluorescence Staining - ANSWER Cells are counted under a microscope or flow
cytometer
, In fluorescent staining, the end product results in live cells staining ___________? -
ANSWER Green
In fluorescent staining, the end product results in dead cells staining ___________? -
ANSWER Red
Coulter counting - ANSWER Detects electrical resistance change due to cell
density
Viable Cell Counts - ANSWER Samples are diluted and grown on solid media
What type of cells are counted when using the viable plate count method? -
ANSWER Living
Countable Range - ANSWER 30-300 CFU/ml
Optical Density - ANSWER -Measured with spectrophotometer
-Light is passed thru culture and measured on other side
Which method of measuring growth is considered an indirect approach? -
ANSWER Optical density
Which method of measuring growth can be used on living or dead cells? -
ANSWER Fluorescent stain
How is the pour plate technique set up? - ANSWER The sample is mixed with a
warm agar ranging from 45-50 C, poured onto sterile plated and swirled to mix
How is the spread plate technique set up? - ANSWER The sample is poured onto
a solid medium and spread using a L spreader
What cell counting method is used for counting colonies from drinking water? -
ANSWER Membrane filtration
What method of measuring growth is used in food/water testing? - ANSWER MPN
(most probable number)
Steps of Biofilm Formation - ANSWER 1. Attachment of planktonic cells
2. Cells become sessile
3. Growth & Division on substrate
4. Production of extracellular polymeric substance
5. Attachment of secondary colonizers & dispersion
Quorum Sensing - ANSWER Cell to cell communication regarding cell density
What is the term that refers to the small molecules that allow microbes to detect cell
density in a biofilm? - ANSWER Autoinducers
What is EPS composed of? - ANSWER Hydrated polysaccharide gel, other macros
& channels
Already Passed
4 Basic Steps of binary fission - ANSWER 1. Growth of cell size
2. Replication of DNA
3. Division of cytoplasm
4. Septum formation & cell division
Z Ring Assembly - ANSWER FtsZ assembles Z ring to form divisome
Generation Time - ANSWER time it takes to double the population
Lag Phase - ANSWER Cells adjust to culture medium; no change in population
What factors determine the duration of the lag phase? - ANSWER Genetic
makeup, media composition, initial inoculum size
During which phase of the growth curve is it most appropriate for the use of
antibiotics? - ANSWER Log phase
Following the death phase of the growth curve, ____ cells are considered the
surviving cells & are considered clinically important due to their association with
chronic infections, such as Tuberculosis. - ANSWER Persisters
Log Phase - ANSWER Binary fission occurs; cell replication > cell death
Stationary Phase - ANSWER Resources become depleted; cell respiration=cell
death
Death Phase - ANSWER Endospores can form; cell replication < cell death
Close System Cultures - ANSWER Have finite resources
Open System Cultures - ANSWER -Nutrients and air are replenished
-Dead cells and waste are removed
-Beneficial for industrial microbiology
Microscopic Cell Count - ANSWER Cells are counted under a microscope using a
laser etched slide
In using the direct microscopic cell count method, you will be able to distinguish
between live vs dead cells. - ANSWER False
Fluorescence Staining - ANSWER Cells are counted under a microscope or flow
cytometer
, In fluorescent staining, the end product results in live cells staining ___________? -
ANSWER Green
In fluorescent staining, the end product results in dead cells staining ___________? -
ANSWER Red
Coulter counting - ANSWER Detects electrical resistance change due to cell
density
Viable Cell Counts - ANSWER Samples are diluted and grown on solid media
What type of cells are counted when using the viable plate count method? -
ANSWER Living
Countable Range - ANSWER 30-300 CFU/ml
Optical Density - ANSWER -Measured with spectrophotometer
-Light is passed thru culture and measured on other side
Which method of measuring growth is considered an indirect approach? -
ANSWER Optical density
Which method of measuring growth can be used on living or dead cells? -
ANSWER Fluorescent stain
How is the pour plate technique set up? - ANSWER The sample is mixed with a
warm agar ranging from 45-50 C, poured onto sterile plated and swirled to mix
How is the spread plate technique set up? - ANSWER The sample is poured onto
a solid medium and spread using a L spreader
What cell counting method is used for counting colonies from drinking water? -
ANSWER Membrane filtration
What method of measuring growth is used in food/water testing? - ANSWER MPN
(most probable number)
Steps of Biofilm Formation - ANSWER 1. Attachment of planktonic cells
2. Cells become sessile
3. Growth & Division on substrate
4. Production of extracellular polymeric substance
5. Attachment of secondary colonizers & dispersion
Quorum Sensing - ANSWER Cell to cell communication regarding cell density
What is the term that refers to the small molecules that allow microbes to detect cell
density in a biofilm? - ANSWER Autoinducers
What is EPS composed of? - ANSWER Hydrated polysaccharide gel, other macros
& channels
