BIOD 171 Portage Learning Exam 4
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What is another name for a liquid growth media, what are the basic components? - CORRECT
ANSWER - Nutrient broth. The basic components are sugar, amino acids, and vitamins.
What is selective media? - CORRECT ANSWER - Selective media is when you only
allow certain microbes to grow while restricting the growth of the other microbes.
What is differential media? - CORRECT ANSWER - Differential media is used to
differentiate between two or more related microbes.
What are the requirements of a fastidious media? - CORRECT ANSWER - Fastidious
media has complex growth requirements. If it is absent, it will not grow.
What is agar? - CORRECT ANSWER - It is a liquid growth media that has a hardening
agent. It is used to allow microbes to grow.
True or False: LB agar is classified as non-selective, differential media. - CORRECT
ANSWER - False
What are the three forms of hemolysis found on blood agar plates? - CORRECT
ANSWER - Alpha hemolysis: Are greenish, brown due to incomplete lysis of red blood
cells.
Beta hemolysis: Capacity of a microbe to completely lyse red blood cells. The resulting lysis
presents as a distinct zone of clearing around the growing colony
Gamma hemolysis: White/tan in color with red background.
, What is the primary purpose of Columbia CNA agar? - CORRECT ANSWER - It is sued
to isolate Gram-positive microbes.
Name the type of plate derived from BAP that contains lysed red blood cells. - CORRECT
ANSWER - Lysed red blood cells.
Define the selective and differential abilities of a MacConkey agar plate. - CORRECT
ANSWER - It is selective because it only allows Gram-negative microbes to grow. It is
differential because it is capable of distinguishing between microbes capable of fermenting
lactose and those that don't.
What colors would you expect to see on an EMB plate containing E. coli.? - CORRECT
ANSWER - A green sheen.
What is the name of the process of spreading a bacterial culture onto a Petri dish? - CORRECT
ANSWER - Plating.
What is the primary advantage of plating a bacterial culture as opposed to having it grow in
solution? - CORRECT ANSWER - The advantage is that it holds the cells in place.
What is the purpose of the quadrant streak approach? - CORRECT ANSWER - To
generate an individual colony so a single pure culture can be picked.
In a three-phased dilution gradient, which phase most likely contains individual colonies: phase 1
or phase 3? - CORRECT ANSWER - Phase 3 streaks.
A
Sorbitol- MacConkey Agar: PINK, TO detect the presence of the pathogenic strain or E.coli.
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What is another name for a liquid growth media, what are the basic components? - CORRECT
ANSWER - Nutrient broth. The basic components are sugar, amino acids, and vitamins.
What is selective media? - CORRECT ANSWER - Selective media is when you only
allow certain microbes to grow while restricting the growth of the other microbes.
What is differential media? - CORRECT ANSWER - Differential media is used to
differentiate between two or more related microbes.
What are the requirements of a fastidious media? - CORRECT ANSWER - Fastidious
media has complex growth requirements. If it is absent, it will not grow.
What is agar? - CORRECT ANSWER - It is a liquid growth media that has a hardening
agent. It is used to allow microbes to grow.
True or False: LB agar is classified as non-selective, differential media. - CORRECT
ANSWER - False
What are the three forms of hemolysis found on blood agar plates? - CORRECT
ANSWER - Alpha hemolysis: Are greenish, brown due to incomplete lysis of red blood
cells.
Beta hemolysis: Capacity of a microbe to completely lyse red blood cells. The resulting lysis
presents as a distinct zone of clearing around the growing colony
Gamma hemolysis: White/tan in color with red background.
, What is the primary purpose of Columbia CNA agar? - CORRECT ANSWER - It is sued
to isolate Gram-positive microbes.
Name the type of plate derived from BAP that contains lysed red blood cells. - CORRECT
ANSWER - Lysed red blood cells.
Define the selective and differential abilities of a MacConkey agar plate. - CORRECT
ANSWER - It is selective because it only allows Gram-negative microbes to grow. It is
differential because it is capable of distinguishing between microbes capable of fermenting
lactose and those that don't.
What colors would you expect to see on an EMB plate containing E. coli.? - CORRECT
ANSWER - A green sheen.
What is the name of the process of spreading a bacterial culture onto a Petri dish? - CORRECT
ANSWER - Plating.
What is the primary advantage of plating a bacterial culture as opposed to having it grow in
solution? - CORRECT ANSWER - The advantage is that it holds the cells in place.
What is the purpose of the quadrant streak approach? - CORRECT ANSWER - To
generate an individual colony so a single pure culture can be picked.
In a three-phased dilution gradient, which phase most likely contains individual colonies: phase 1
or phase 3? - CORRECT ANSWER - Phase 3 streaks.
A
Sorbitol- MacConkey Agar: PINK, TO detect the presence of the pathogenic strain or E.coli.
