©JUSTTRACY EXAM SOLUTIONS
21/11/202410:20AM
Microbiology Lab Midterm Barbosa
Exam Questions And Improved
Responses
parfocal - answers✔✔only a little fine adjustment is needed to bring a specimen into focus
when switching from low to high power
iris diaphragm - answers✔✔used to vary the illumination of the object being viewed
rheostat - answers✔✔changes the intensity of the light beam
aseptic technique - answers✔✔prevent the contamination of the culture and spreading of
microorganisms into the environment
How can bacterial culture media be distinguished? - answers✔✔composition, consistency,
and purpose
Advantages of Solid Media - answers✔✔allows for isolation of bacteria as pure culture;
mixed bacteria can be separated
agar - answers✔✔bacteriologically inert
semisolid media - answers✔✔useful for the cultivation of microaerophilic bacteria or
determination of bacterial motility
all purpose media - answers✔✔TSA (tryptic soy agar) and TSB (tryptic soy broth)
turbid - answers✔✔diffusion uniform throughout the broth
sediment - answers✔✔settles at the bottom
, ©JUSTTRACY EXAM SOLUTIONS
21/11/202410:20AM
pellicle - answers✔✔flocculent growth, some may float to the top
endospores - answers✔✔not readily killed by many antimicrobial treatments (may be central,
terminal, or subterminal)
germination - answers✔✔not a reproductive process, but a process of differentiation
gram stain - answers✔✔1. crystal violet
2. iodine mordant
3. ethanol decolorizer
4. safranin counterstain
example of gram positive bacteria - answers✔✔M. luteus
example of gram negative bacteria - answers✔✔E. coli
endospore staining - answers✔✔1. malachite green
2. steaming mordant
3. water decolorizer
4. safranin counterstain
microbial metabolism - answers✔✔the means by which a microorganism obtains the energy
and nutrients it needs to live and reproduce
cellular metabolism - answers✔✔sum of all metabolic processes (catabolism and anabolism)
fermentation - answers✔✔cells partially break down carbohydrates to obtain energy, occurs
after glycolysis when there is a deficiency in oxygen
21/11/202410:20AM
Microbiology Lab Midterm Barbosa
Exam Questions And Improved
Responses
parfocal - answers✔✔only a little fine adjustment is needed to bring a specimen into focus
when switching from low to high power
iris diaphragm - answers✔✔used to vary the illumination of the object being viewed
rheostat - answers✔✔changes the intensity of the light beam
aseptic technique - answers✔✔prevent the contamination of the culture and spreading of
microorganisms into the environment
How can bacterial culture media be distinguished? - answers✔✔composition, consistency,
and purpose
Advantages of Solid Media - answers✔✔allows for isolation of bacteria as pure culture;
mixed bacteria can be separated
agar - answers✔✔bacteriologically inert
semisolid media - answers✔✔useful for the cultivation of microaerophilic bacteria or
determination of bacterial motility
all purpose media - answers✔✔TSA (tryptic soy agar) and TSB (tryptic soy broth)
turbid - answers✔✔diffusion uniform throughout the broth
sediment - answers✔✔settles at the bottom
, ©JUSTTRACY EXAM SOLUTIONS
21/11/202410:20AM
pellicle - answers✔✔flocculent growth, some may float to the top
endospores - answers✔✔not readily killed by many antimicrobial treatments (may be central,
terminal, or subterminal)
germination - answers✔✔not a reproductive process, but a process of differentiation
gram stain - answers✔✔1. crystal violet
2. iodine mordant
3. ethanol decolorizer
4. safranin counterstain
example of gram positive bacteria - answers✔✔M. luteus
example of gram negative bacteria - answers✔✔E. coli
endospore staining - answers✔✔1. malachite green
2. steaming mordant
3. water decolorizer
4. safranin counterstain
microbial metabolism - answers✔✔the means by which a microorganism obtains the energy
and nutrients it needs to live and reproduce
cellular metabolism - answers✔✔sum of all metabolic processes (catabolism and anabolism)
fermentation - answers✔✔cells partially break down carbohydrates to obtain energy, occurs
after glycolysis when there is a deficiency in oxygen
