MicroBio 202L Prep Guide 2025/26 | Latest
Verified Quizzes and Answers | A+ Guarantee
Gram negative bacteria have what type of peptidoglycan layer? - Thin
This bacterium is Gram-positive, produces a yellow pigment, and is beta-hemolytic? -
staphylococcus aureus
Which of the following are scenarios that help create antibiotic resistance? - Random
Mutations, Overuse of antibiotics, Used to treate viral infections
In exercise 10. we inoculated Serratia marcescens onto agar plates containing streptomycin, an
antibiotic that normally kills bacteria. However, due to ____, a very small minority of the
bacteria did survive and grow. - mutation-acquired antibiotic resistance
Even though it was developed in the 1880's the acid-fast stain is still important because it is an
aid in the diagnosis of? - Tuberculosis
What causes slide A to turn yellow? - fermentations of sugar
The Gram Stain and Acid-Fast Stain are considered ___ stains. - Differential
What is the purpose of Acid-Fast staining? - To distinguish between acid-fast and non-
acid-fast bacterial
Some microorganisms are able to enzymatically repair DNA damaged by ultraviolet radiation if
they are exposed to strong visible light. This process is called? - photoreactivation
Which statement is true? - The longer the bacteria is exposed to the UV light, the greater
the killing effect observed
Ionizing radiation is used in medical settings for what purpose? - Sterilization
Cells have no net movement of water in this type of solution (it does provide an excellent
environment for bacterial growth)? - Hypotonic, Hypertonic, Isotonic
Mannitol Salt Agar is selective for members of the genus Staphylococcus because it contains? -
a very high amount of salt (7.55 NaCl)
When bacterial cells are placed in a hypertonic solution, such as 25% sodium chloride solution,
the resulting process is called? - plasmolysis
Acid-fact bacteria have what type of cell wall? - High lipid
, Thermophile - an organism that has adapted to living in very high temperatures (heat),
such as bacteria or algae
Mesophile - bacteria that prefers moderate temperature and develops best at
temperatures between 25 C and 40 C
Nutrient + water - Nutrient Broth
Agar + Nutrient + Water - Nutrient Agar
Growth media needs to be? - Sterile and autoclave
Autoclaving - Method of sterilization using steam under pressure
Assume you have an ordinary bottle of milk (undiluted of 1:1) and you transfer 4 ml from it to a
tube containing 16 ml of sterile diluent. What is the dilution you have just made? - 1:5
List three characteristics of a coliform. - rod-shaped, gram negative, non-spore forming
bacteria that ferment lactose
You've just completed the 3 testing's steps for the bacterial examination of water (presumptive,
confirmed, completed) from Experiment 16. The results were all positive. What does this tell
you? - Coliforms are present (unable to determine whether they are fecal or non-fecal)
Which media is selective and differential for coliforms because it inhibits Gram positive bacteria
and is differential for lactose fermenters? - Eosin Methylene Blue
Which reagent is used for the Citrate test? - None
Sugar fermentation tubes contain small inverted vitals (Durham tubes) that are used to detect? -
gas production
This type of antibiotic works against both Gram (+) (-) bacteria? - Broad spectrum
A positive caseinase test can be observed by a __ on the casein agar around the bacterial
colony. - Clearing
What is the purpose of the IMVIC test? - To distinguish between fecal and non-fecal
coliforms
The purpose of serial dilution - extracellular enzymes were produced breaking down
casein
When testing for the production of a-amylase, starch hydrolysis can be determined by flooding
starch plates with? - iodine
Verified Quizzes and Answers | A+ Guarantee
Gram negative bacteria have what type of peptidoglycan layer? - Thin
This bacterium is Gram-positive, produces a yellow pigment, and is beta-hemolytic? -
staphylococcus aureus
Which of the following are scenarios that help create antibiotic resistance? - Random
Mutations, Overuse of antibiotics, Used to treate viral infections
In exercise 10. we inoculated Serratia marcescens onto agar plates containing streptomycin, an
antibiotic that normally kills bacteria. However, due to ____, a very small minority of the
bacteria did survive and grow. - mutation-acquired antibiotic resistance
Even though it was developed in the 1880's the acid-fast stain is still important because it is an
aid in the diagnosis of? - Tuberculosis
What causes slide A to turn yellow? - fermentations of sugar
The Gram Stain and Acid-Fast Stain are considered ___ stains. - Differential
What is the purpose of Acid-Fast staining? - To distinguish between acid-fast and non-
acid-fast bacterial
Some microorganisms are able to enzymatically repair DNA damaged by ultraviolet radiation if
they are exposed to strong visible light. This process is called? - photoreactivation
Which statement is true? - The longer the bacteria is exposed to the UV light, the greater
the killing effect observed
Ionizing radiation is used in medical settings for what purpose? - Sterilization
Cells have no net movement of water in this type of solution (it does provide an excellent
environment for bacterial growth)? - Hypotonic, Hypertonic, Isotonic
Mannitol Salt Agar is selective for members of the genus Staphylococcus because it contains? -
a very high amount of salt (7.55 NaCl)
When bacterial cells are placed in a hypertonic solution, such as 25% sodium chloride solution,
the resulting process is called? - plasmolysis
Acid-fact bacteria have what type of cell wall? - High lipid
, Thermophile - an organism that has adapted to living in very high temperatures (heat),
such as bacteria or algae
Mesophile - bacteria that prefers moderate temperature and develops best at
temperatures between 25 C and 40 C
Nutrient + water - Nutrient Broth
Agar + Nutrient + Water - Nutrient Agar
Growth media needs to be? - Sterile and autoclave
Autoclaving - Method of sterilization using steam under pressure
Assume you have an ordinary bottle of milk (undiluted of 1:1) and you transfer 4 ml from it to a
tube containing 16 ml of sterile diluent. What is the dilution you have just made? - 1:5
List three characteristics of a coliform. - rod-shaped, gram negative, non-spore forming
bacteria that ferment lactose
You've just completed the 3 testing's steps for the bacterial examination of water (presumptive,
confirmed, completed) from Experiment 16. The results were all positive. What does this tell
you? - Coliforms are present (unable to determine whether they are fecal or non-fecal)
Which media is selective and differential for coliforms because it inhibits Gram positive bacteria
and is differential for lactose fermenters? - Eosin Methylene Blue
Which reagent is used for the Citrate test? - None
Sugar fermentation tubes contain small inverted vitals (Durham tubes) that are used to detect? -
gas production
This type of antibiotic works against both Gram (+) (-) bacteria? - Broad spectrum
A positive caseinase test can be observed by a __ on the casein agar around the bacterial
colony. - Clearing
What is the purpose of the IMVIC test? - To distinguish between fecal and non-fecal
coliforms
The purpose of serial dilution - extracellular enzymes were produced breaking down
casein
When testing for the production of a-amylase, starch hydrolysis can be determined by flooding
starch plates with? - iodine
