Microbio 150 Lab exam 1 PVCC
Questions and Answers 100% Pass
When preparing to view a specimen on a compound microscope in the lab, one should
__________ begin with the 4x objective - ✔✔Always
Where should used gloves be disposed of in the microbiology lab - ✔✔In the bio-hazard
waste container
Before putting a dust cover over the microscope and placing it in the cabinet, which
objective lens should be rotated over the stage - ✔✔4x
On the microscope, what concentrates the light on the specimen? - ✔✔Condenser lens
On the microscope, what bends light passing through the specimen to create a real
image - ✔✔Objective lens
On the microscope, what allows for more or less light to be directed onto the specimen -
✔✔Iris diaphragm
On the microscope, what gives you clarity of the image - ✔✔Resolution
Katelyn Whitman, All Rights Reserved © 2025 1
, Why is desiccating your inoculating loop important? When should this be done? -
✔✔To ensure it is sterilized, done so no cross contamination happens
During an aseptic transfer, when do you pass the mouth of the test tube through the
flame? - ✔✔Before and after dipping loop in
During the broth to slide aseptic transfer, a __________ was used to obtain a pure
culture from a __________. - ✔✔Loop, broth
Prior to staining, smears of microorganisms are heat-fixed in order to - ✔✔Attach it
firmly to the slide
The term that refers to the purposeful addition of microorganisms into a nutrient
medium is - ✔✔Inoculation
True or false: In the microbiology lab, it is acceptable to move your loop around while
waiting for it to dry. - ✔✔False
Which stain was used during the negative staining procedure? - ✔✔Nigrosin
Which stain was used during the simple staining procedure? - ✔✔Methylene blue
True or false: During a negative stain, the bacteria are heat fixed. - ✔✔False
Bacteria in the Mycobacterium genus have the presence of what component in the cell
wall that causes them to be acid-fast? - ✔✔Peptidoglycan
Katelyn Whitman, All Rights Reserved © 2025 2
Questions and Answers 100% Pass
When preparing to view a specimen on a compound microscope in the lab, one should
__________ begin with the 4x objective - ✔✔Always
Where should used gloves be disposed of in the microbiology lab - ✔✔In the bio-hazard
waste container
Before putting a dust cover over the microscope and placing it in the cabinet, which
objective lens should be rotated over the stage - ✔✔4x
On the microscope, what concentrates the light on the specimen? - ✔✔Condenser lens
On the microscope, what bends light passing through the specimen to create a real
image - ✔✔Objective lens
On the microscope, what allows for more or less light to be directed onto the specimen -
✔✔Iris diaphragm
On the microscope, what gives you clarity of the image - ✔✔Resolution
Katelyn Whitman, All Rights Reserved © 2025 1
, Why is desiccating your inoculating loop important? When should this be done? -
✔✔To ensure it is sterilized, done so no cross contamination happens
During an aseptic transfer, when do you pass the mouth of the test tube through the
flame? - ✔✔Before and after dipping loop in
During the broth to slide aseptic transfer, a __________ was used to obtain a pure
culture from a __________. - ✔✔Loop, broth
Prior to staining, smears of microorganisms are heat-fixed in order to - ✔✔Attach it
firmly to the slide
The term that refers to the purposeful addition of microorganisms into a nutrient
medium is - ✔✔Inoculation
True or false: In the microbiology lab, it is acceptable to move your loop around while
waiting for it to dry. - ✔✔False
Which stain was used during the negative staining procedure? - ✔✔Nigrosin
Which stain was used during the simple staining procedure? - ✔✔Methylene blue
True or false: During a negative stain, the bacteria are heat fixed. - ✔✔False
Bacteria in the Mycobacterium genus have the presence of what component in the cell
wall that causes them to be acid-fast? - ✔✔Peptidoglycan
Katelyn Whitman, All Rights Reserved © 2025 2
