Microbiology LAB Exam 1 2025 Common Questions and Answers

Microbiology LAB Exam 1 2025:Cmmon Questions and Answers
= How many decimel places, to the right of base - ansSix places --- .000 000



6.02x 10 = moving the decimel over how many spaces? - ans23



An example of a producer is what? - ansAlgae are producers that are found in a pond.



At what temperature, pressure, and time was required to sterilize our TSA medium using the
autoclave? - ansThe autoclave will reach 121˚C at 15 pounds of pressure. 15 minutes is required to
sterilize a normal load (however if larger amounts of liquid are being sterilized, more time may be required.)



Compare and contrast these three techniques by pattern of growth on the surface - ansStreak plates require
dilution by flaming the loop after streaking each quadrant and only taking 3 streaks from the previous quadrant
into the new quadrant. By doing this, each quadrant is more dilute than the previous quadrant. The 4th
quadrant should always be dilute enough to contain isolated colonies.

Pour plates have isolated colonies of bacteria evenly spread throughout the medium (not just on the surface,
but all throughout the agar.). In the Pour Plate procedure, the bacteria is diluted in sterile "water blanks" prior
to plating the bacteria and pouring agar over the bacteria. The bacteria sample that is dilute enough will
produce isolated colonies throughout the medium (rather than just on the surface.)

Spread Plate procedure is similar, to the pour plate in that the bacteria is diluted prior to inoculation on the
plate. The bacteria sample is placed on an agar plate and then spread evenly across the surface of the agar
(rather than throughout the medium).



Compare and contrast these three techniques by where bacteria grow in the media - ansStreak Plate - bacteria
grow only on the surface

Pour Plate - bacteria grow throughout the media

Spread Plate - bacteria grow only on the surface



Convert Celsius to Fahrenheit - ansF = (9xC)/5 +32

, Convert Fahrenheit to Celsius - ansC = 5/9 (F - 32)



define and identify the following agar slant growth patterns -Arborescent- - ansbranched growth from the
original streak



define and identify the following agar slant growth patterns -Beaded - ansIsolated colonies toward the top of
the slant



define and identify the following agar slant growth patterns -Echinulate - anspointed (spiny) edge of growth



define and identify the following agar slant growth patterns -Filiform - ansEvenly distributed on slant (only
where streaked).



define and identify the following agar slant growth patterns -Rhizoid - ansRoot like distribution of growth
(larger branches coming from the streak).



define and identify the following agar slant growth patterns -Spreading - ansGrowth has spread out beyond the
original streak



define and identify the following broth culture growth patterns -Flocculant - ansclumps of growth throughout



define and identify the following broth culture growth patterns -Pellicle - ansA film of growth at the top of the
broth



define and identify the following broth culture growth patterns -Sediment - ansPrecipitate that falls to the
bottom of the tube



define and identify the following broth culture growth patterns -Turbidity- - ansGrowth evenly distributed
throughout.