BIO 250 MICROBIOLOGY LAB 1 2026
PRACTICE LAB QUESTIONS AND SOLUTIONS
GUARANTEED PASS
◉ an antibiotic is a synthetic drug produced in a laboratory. Answer:
false
◉ ______ is a genus that produces antibiotics. Answer: all of the
above: Bacillys, Cephalosporium, and Streptomyces
◉ penicillin is produced by a ____. Answer: mold
◉ novobiocin is a bacteriostatic, narrow-spectrum antibiotic.
Answer: true
◉ gentamicin is synthesized by a ___. Answer: gram-positive bacteria
◉ bacteriocidal agents kill bacteria by _____. Answer: cell wall lysis
◉ resistant bacteria will exhibit ____ during a kirby-bauer diffusion
test. Answer: no zone of inhibition
,◉ a spreader is used when inoculating a kirby-bauer diffusion plate
to ___. Answer: create a uniform bacterial lawn
◉ zones of inhibition should be measured after they exceed 25 mm.
Answer: false
◉ the diagram below illustrates resistance to drug ___ (nothing
around A, little around B, large around C). Answer: A
◉ ______ are asexually produced spores of the penicillum fungus.
Answer: conidia
◉ describes individual colonies on a plate's surface. Answer: colony
forming unit
◉ the number of individuals doubles each generation. Answer:
exponential growth
◉ cloudiness of a fluid caused by large numbers of
particles/organisms. Answer: turbidity
◉ the measure of the light intensity absorbed by a sample. Answer:
absorbance
, ◉ asexual reproduction resulting in two daughter cells. Answer:
binary fission
◉ order the steps for performing a dilution series. Answer: 1.
determine the dilutions of the dilution tubes
2. determine which plate is the countable plate
3. calculate the concentration in the original tube
◉ binary fission is a method of sexual reproduction where a single
cell (parent cell) will split into four cells (daughter cells). Answer:
false
◉ plates with ____ colonies per plate are used to calculate CFUs.
Answer: 30-300
◉ if the 1:100 plate contained 50 colonies, the 1:1000 plate
contained 200 colonies, and the 1:10000 dilution plate contained
1000 colonies which plate would you use to determine the original
culture concentrations?. Answer: the 1:100 plate
◉ in binary fission bacterial cells grow ___. Answer: exponentially
◉ when one bacterial cell undergoes binary fission, there will be ___
cells present on the 5th generation. Answer: 16
PRACTICE LAB QUESTIONS AND SOLUTIONS
GUARANTEED PASS
◉ an antibiotic is a synthetic drug produced in a laboratory. Answer:
false
◉ ______ is a genus that produces antibiotics. Answer: all of the
above: Bacillys, Cephalosporium, and Streptomyces
◉ penicillin is produced by a ____. Answer: mold
◉ novobiocin is a bacteriostatic, narrow-spectrum antibiotic.
Answer: true
◉ gentamicin is synthesized by a ___. Answer: gram-positive bacteria
◉ bacteriocidal agents kill bacteria by _____. Answer: cell wall lysis
◉ resistant bacteria will exhibit ____ during a kirby-bauer diffusion
test. Answer: no zone of inhibition
,◉ a spreader is used when inoculating a kirby-bauer diffusion plate
to ___. Answer: create a uniform bacterial lawn
◉ zones of inhibition should be measured after they exceed 25 mm.
Answer: false
◉ the diagram below illustrates resistance to drug ___ (nothing
around A, little around B, large around C). Answer: A
◉ ______ are asexually produced spores of the penicillum fungus.
Answer: conidia
◉ describes individual colonies on a plate's surface. Answer: colony
forming unit
◉ the number of individuals doubles each generation. Answer:
exponential growth
◉ cloudiness of a fluid caused by large numbers of
particles/organisms. Answer: turbidity
◉ the measure of the light intensity absorbed by a sample. Answer:
absorbance
, ◉ asexual reproduction resulting in two daughter cells. Answer:
binary fission
◉ order the steps for performing a dilution series. Answer: 1.
determine the dilutions of the dilution tubes
2. determine which plate is the countable plate
3. calculate the concentration in the original tube
◉ binary fission is a method of sexual reproduction where a single
cell (parent cell) will split into four cells (daughter cells). Answer:
false
◉ plates with ____ colonies per plate are used to calculate CFUs.
Answer: 30-300
◉ if the 1:100 plate contained 50 colonies, the 1:1000 plate
contained 200 colonies, and the 1:10000 dilution plate contained
1000 colonies which plate would you use to determine the original
culture concentrations?. Answer: the 1:100 plate
◉ in binary fission bacterial cells grow ___. Answer: exponentially
◉ when one bacterial cell undergoes binary fission, there will be ___
cells present on the 5th generation. Answer: 16
