BIOL 2051 LAB QUIZZES 1-4. EXAM 2025
QUESTIONS AND ANSWERS
What method of sterilization is used to sterilize the media you use in the lab?
Select one:
a. electromagnetic radiation
b. gas
c. filtration
d. moist heat sterilization - ANS d. moist heat sterilization
Allergies have been bothering you lately. As you were inoculating your streak plate with E. coli
you sneeze. With a plate in one hand and an inoculating loop in the other you were unable to
quickly cover your mouth. You tried to sneeze into your arm but your unstifled sneeze was
greater than your arm could shield. Following incubation of your plate, what do you expect to
see on the plate next lab?
Select one or more:
a. Nothing because you did not inoculate the plate.
b. There will be E. coli along with bacteria from your mouth on the plate.
c. Nothing because the media in the plate was sterilized.
d. Microorganisms are in the air transiently so there could be growth from contaminates in the
air. - ANS b. There will be E. coli along with bacteria from your mouth on the plate.
d. Microorganisms are in the air transiently so there could be growth from contaminates in the
air.
Which of the following term describe the optical properties of a colony?
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,Select one:
a. translucent
b. dull
c. shiny
d. irregular - ANS a. translucent
Which of the following terms describe the whole colony shape of a colony?
Select one:
a. umbonate
b. lobate
c. filamentous
d. round - ANS d. round
Which of following is used to determine colony morphology of a microorganism?
Select one or more:
a. your eye
b. a colony
c. a microscope
d. a broth culture - ANS a. your eye
b. a colony
When you calculate population standard deviation, you divide the squared differences by the
total number of population observations.
Select one:
True
False - ANS True
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, What is the correct order of events in demonstrating aseptic technique to prepare a smear
from a broth culture? (You may use an answer choice more than once if needed. Your answer
needs to be written with no spaces between letters; for example: abcdefgh)
a. Replace the cap on the test tube;
b. Allow loop to cool;
c. Remove a loopful of microorganisms from the broth;
d. Heat the loop and wire until red hot;
e. Place a loopful of microorganisms onto the slide;
f. Flame the mouth of the culture tube;
g. Gently shake the broth culture to suspend the microorganisms;
h. Remove the cap from the tube. - ANS gdbhfcfaed
In preparing most smears, heat fixation is done before staining. What does heat fixation do to
the bacteria placed on the microscope slide?
Select one or more:
a. Sticks the bacteria to the slide
b. Kills the bacteria
c. Lyses the bacteria
d. Allows enzymes and other cellular processes to continue - ANS a. Sticks the bacteria to the
slide
b. Kills the bacteria
A smear can be made from
Select one:
a. Bacteria growing on a solid medium
b. A broth culture
c. A colony on a plate
d. All of the above - ANS d. All of the above
3 @COPYRIGHT THESTAR 2025/2026
QUESTIONS AND ANSWERS
What method of sterilization is used to sterilize the media you use in the lab?
Select one:
a. electromagnetic radiation
b. gas
c. filtration
d. moist heat sterilization - ANS d. moist heat sterilization
Allergies have been bothering you lately. As you were inoculating your streak plate with E. coli
you sneeze. With a plate in one hand and an inoculating loop in the other you were unable to
quickly cover your mouth. You tried to sneeze into your arm but your unstifled sneeze was
greater than your arm could shield. Following incubation of your plate, what do you expect to
see on the plate next lab?
Select one or more:
a. Nothing because you did not inoculate the plate.
b. There will be E. coli along with bacteria from your mouth on the plate.
c. Nothing because the media in the plate was sterilized.
d. Microorganisms are in the air transiently so there could be growth from contaminates in the
air. - ANS b. There will be E. coli along with bacteria from your mouth on the plate.
d. Microorganisms are in the air transiently so there could be growth from contaminates in the
air.
Which of the following term describe the optical properties of a colony?
1 @COPYRIGHT THESTAR 2025/2026
,Select one:
a. translucent
b. dull
c. shiny
d. irregular - ANS a. translucent
Which of the following terms describe the whole colony shape of a colony?
Select one:
a. umbonate
b. lobate
c. filamentous
d. round - ANS d. round
Which of following is used to determine colony morphology of a microorganism?
Select one or more:
a. your eye
b. a colony
c. a microscope
d. a broth culture - ANS a. your eye
b. a colony
When you calculate population standard deviation, you divide the squared differences by the
total number of population observations.
Select one:
True
False - ANS True
2 @COPYRIGHT THESTAR 2025/2026
, What is the correct order of events in demonstrating aseptic technique to prepare a smear
from a broth culture? (You may use an answer choice more than once if needed. Your answer
needs to be written with no spaces between letters; for example: abcdefgh)
a. Replace the cap on the test tube;
b. Allow loop to cool;
c. Remove a loopful of microorganisms from the broth;
d. Heat the loop and wire until red hot;
e. Place a loopful of microorganisms onto the slide;
f. Flame the mouth of the culture tube;
g. Gently shake the broth culture to suspend the microorganisms;
h. Remove the cap from the tube. - ANS gdbhfcfaed
In preparing most smears, heat fixation is done before staining. What does heat fixation do to
the bacteria placed on the microscope slide?
Select one or more:
a. Sticks the bacteria to the slide
b. Kills the bacteria
c. Lyses the bacteria
d. Allows enzymes and other cellular processes to continue - ANS a. Sticks the bacteria to the
slide
b. Kills the bacteria
A smear can be made from
Select one:
a. Bacteria growing on a solid medium
b. A broth culture
c. A colony on a plate
d. All of the above - ANS d. All of the above
3 @COPYRIGHT THESTAR 2025/2026
