MICROBIOLOGY LAB FINAL EXAM QUESTIONS AND ANSWERS 2025
What type of media would you use to allow growth of many bacterials species from the sample
enviornment? - (ANSWER)TSA
triptic soy agar
Where would you incubate a soil sample?
Mouth/touch plate?
Sample from frozen tundra why? - (ANSWER)soil - 22-25
mouth/touch- 37
Frozen tundra- 4
For proper growth to occur, the sample must be incubated/refrigerated at the temperature its usual
environment is.
Aseptic Technique: transferring cultures from liquid to plate or liquid to liquid - (ANSWER)-Hold
inoculating loop in flame for 2-3 seconds while red hot
-remove the cap from the broth culture and flame the mouth of the tube by passing it through the flame
-Insert loop and withdraw
-re-flame mouth of tube, and cap it
-touch the loop to the plate and streak it back and forth a few times
-cover plate & reflame loop
Define Resolution - (ANSWER)The ability to distinguish two small objects apart from each other.
Define Parfocal - (ANSWER)When you focus on a specimen under a low magnification, you can switch
the objective to a higher magnification and your specimen will be almost in focus.
Define Magnification - (ANSWER)-enlarging an image.
can be calculated by multiplying the magnification of the objective lens by the magnification of the eye
piece
, MICROBIOLOGY LAB FINAL EXAM QUESTIONS AND ANSWERS 2025
Eyepiece - (ANSWER)the lens or group of lens that is closest to the eye in a microscope
Objective Lens - (ANSWER)The lens or system of lens in a microscope that is nearest to the object being
viewed
Stage - (ANSWER)a small platform on a microscope where the specimen is mounted for examination
Iris Diaphragm - (ANSWER)regulates amount of light admitted to a lens
Light Source - (ANSWER)provides light to microscope
Stage control - (ANSWER)controls the stage position (up or down)
On/Off button - (ANSWER)turns microscope on and off
Coarse focus - (ANSWER)focuses the speciman on stage
Fine Focus - (ANSWER)fine tunes the focus of the specimen and various parts of the specimen
Brightness Control - (ANSWER)
What is the purpose of heat fixing after the smear has air dried? - (ANSWER)to make the bacteria adhere
to the slide
Purpose of a simple stain - (ANSWER)stains make otherwise transparent microorganisms visible under a
microscope.
It also helps determine the morphology of the bacterium.
What type of media would you use to allow growth of many bacterials species from the sample
enviornment? - (ANSWER)TSA
triptic soy agar
Where would you incubate a soil sample?
Mouth/touch plate?
Sample from frozen tundra why? - (ANSWER)soil - 22-25
mouth/touch- 37
Frozen tundra- 4
For proper growth to occur, the sample must be incubated/refrigerated at the temperature its usual
environment is.
Aseptic Technique: transferring cultures from liquid to plate or liquid to liquid - (ANSWER)-Hold
inoculating loop in flame for 2-3 seconds while red hot
-remove the cap from the broth culture and flame the mouth of the tube by passing it through the flame
-Insert loop and withdraw
-re-flame mouth of tube, and cap it
-touch the loop to the plate and streak it back and forth a few times
-cover plate & reflame loop
Define Resolution - (ANSWER)The ability to distinguish two small objects apart from each other.
Define Parfocal - (ANSWER)When you focus on a specimen under a low magnification, you can switch
the objective to a higher magnification and your specimen will be almost in focus.
Define Magnification - (ANSWER)-enlarging an image.
can be calculated by multiplying the magnification of the objective lens by the magnification of the eye
piece
, MICROBIOLOGY LAB FINAL EXAM QUESTIONS AND ANSWERS 2025
Eyepiece - (ANSWER)the lens or group of lens that is closest to the eye in a microscope
Objective Lens - (ANSWER)The lens or system of lens in a microscope that is nearest to the object being
viewed
Stage - (ANSWER)a small platform on a microscope where the specimen is mounted for examination
Iris Diaphragm - (ANSWER)regulates amount of light admitted to a lens
Light Source - (ANSWER)provides light to microscope
Stage control - (ANSWER)controls the stage position (up or down)
On/Off button - (ANSWER)turns microscope on and off
Coarse focus - (ANSWER)focuses the speciman on stage
Fine Focus - (ANSWER)fine tunes the focus of the specimen and various parts of the specimen
Brightness Control - (ANSWER)
What is the purpose of heat fixing after the smear has air dried? - (ANSWER)to make the bacteria adhere
to the slide
Purpose of a simple stain - (ANSWER)stains make otherwise transparent microorganisms visible under a
microscope.
It also helps determine the morphology of the bacterium.
