ATI NUTRITION PROCTORED ACTUAL EXAM
WITH VERIFIED CORRECT DETAILED
ANSWERS WITH RATIONALES (VERIFIED
ANSWERS)|GRADED A+ 2023-2024 BRAND
NEW!!!!!!!!!
What is another name for a liquid growth media, and what are the basic components? –
CORRECT ANSWER-Growth media in a liquid form is often referred to
as nutrient broth. As the name implies its composition consists
primarily of essential 'ingredients' such as a rich source of sugars,
amino acids, and vitamins. Together, a nutrient broth provides the
microbe with a source of carbon/energy, which, in turn, encourages its
expansion.
What is selective media?
- CORRECT ANSWER-Selective media allows for only the growth of certain
microbes while restricting the growth of all others.
What is differential media?
- CORRECT ANSWER-Differential media is used to distinguish between two (or
more) related microbes.
What are the requirements of a fastidious microbe?
- CORRECT ANSWER-A fastidious microbe is an organism with complex growth
requirements such that if absent it will not grow. Enriched Medias thus contain
these specific and essential nutrients required for the growth of a particular
subset of microorganisms.
What is agar? - CORRECT ANSWER-In its simplest form agar is liquid growth
media that has had a hardening agent added to it. Agar is created when a
polysaccharide derived from seaweed (algae) extract is added to growth media.
Agar is used to create a solid, smooth surface on which microbes can grow.
, LB agar is classified as a non-selective, differential media
True
False - CORRECT ANSWER-False
LB agar is non-selective and non-differential
What are the three forms of hemolysis found on blood agar plates?
- CORRECT ANSWER-Alpha hemolysis, beta hemolysis, and gamma hemolysis
Alpha hemolysis
- CORRECT ANSWER-Presents with greenish-brown color on blood agar due to
the partial lysis of red blood cells
Beta hemolysis - CORRECT ANSWER-Clear zones on blood agar indicate beta
hemolysis, which is the complete lysis of red blood cells
Gamma hemolysis
- CORRECT ANSWER-PRESENTS A WHITE/TAN ON BLOOD AGAR DUE TO THE
LACK OF HEMOLYTIC ACTIVITY.
What is the primary purpose of Columbia CNA agar? - correct answer-As it suppresses
the growth of Gram-negative bacteria CNA agar is, therefore, used for isolation of
Gram-positive microbes.
Name the type of plate derived from BAP that contains lysed red blood cells - correct
answer-Lysed red blood cells (RBCs) are a primary component in the formulation of
Chocolate agar.
Define the selective and differential abilities of a MacConkey agar plate - correct
answer-MacConkey agar is selective in that only Gram-negative microbes will grow on
the agar -Gram-positive microbes simply do not grow. MacConkey agar is also
considered a differential media as it distinguishes between microbes capable of
fermenting lactose (red colonies) and those that are non-fermenters (white/tan
colonies).
What colors would you expect to see on an EMB plate containing E. coli? - correct
answer-The EMB plate itself is red in color while in the presence of E. coli, the growing
colonies will take on a distinctive metallic green sheen.
What is the name of the process of spreading a bacterial culture onto a petri dish? -
correct answer-Plating. Plating microbes can be done using a sterile loop, a sterile
swab, or a sterilized wire loop. Each device is simply a means of spreading the bacteria,
most commonly in a simple back-and-forth motion, across the plate.
WITH VERIFIED CORRECT DETAILED
ANSWERS WITH RATIONALES (VERIFIED
ANSWERS)|GRADED A+ 2023-2024 BRAND
NEW!!!!!!!!!
What is another name for a liquid growth media, and what are the basic components? –
CORRECT ANSWER-Growth media in a liquid form is often referred to
as nutrient broth. As the name implies its composition consists
primarily of essential 'ingredients' such as a rich source of sugars,
amino acids, and vitamins. Together, a nutrient broth provides the
microbe with a source of carbon/energy, which, in turn, encourages its
expansion.
What is selective media?
- CORRECT ANSWER-Selective media allows for only the growth of certain
microbes while restricting the growth of all others.
What is differential media?
- CORRECT ANSWER-Differential media is used to distinguish between two (or
more) related microbes.
What are the requirements of a fastidious microbe?
- CORRECT ANSWER-A fastidious microbe is an organism with complex growth
requirements such that if absent it will not grow. Enriched Medias thus contain
these specific and essential nutrients required for the growth of a particular
subset of microorganisms.
What is agar? - CORRECT ANSWER-In its simplest form agar is liquid growth
media that has had a hardening agent added to it. Agar is created when a
polysaccharide derived from seaweed (algae) extract is added to growth media.
Agar is used to create a solid, smooth surface on which microbes can grow.
, LB agar is classified as a non-selective, differential media
True
False - CORRECT ANSWER-False
LB agar is non-selective and non-differential
What are the three forms of hemolysis found on blood agar plates?
- CORRECT ANSWER-Alpha hemolysis, beta hemolysis, and gamma hemolysis
Alpha hemolysis
- CORRECT ANSWER-Presents with greenish-brown color on blood agar due to
the partial lysis of red blood cells
Beta hemolysis - CORRECT ANSWER-Clear zones on blood agar indicate beta
hemolysis, which is the complete lysis of red blood cells
Gamma hemolysis
- CORRECT ANSWER-PRESENTS A WHITE/TAN ON BLOOD AGAR DUE TO THE
LACK OF HEMOLYTIC ACTIVITY.
What is the primary purpose of Columbia CNA agar? - correct answer-As it suppresses
the growth of Gram-negative bacteria CNA agar is, therefore, used for isolation of
Gram-positive microbes.
Name the type of plate derived from BAP that contains lysed red blood cells - correct
answer-Lysed red blood cells (RBCs) are a primary component in the formulation of
Chocolate agar.
Define the selective and differential abilities of a MacConkey agar plate - correct
answer-MacConkey agar is selective in that only Gram-negative microbes will grow on
the agar -Gram-positive microbes simply do not grow. MacConkey agar is also
considered a differential media as it distinguishes between microbes capable of
fermenting lactose (red colonies) and those that are non-fermenters (white/tan
colonies).
What colors would you expect to see on an EMB plate containing E. coli? - correct
answer-The EMB plate itself is red in color while in the presence of E. coli, the growing
colonies will take on a distinctive metallic green sheen.
What is the name of the process of spreading a bacterial culture onto a petri dish? -
correct answer-Plating. Plating microbes can be done using a sterile loop, a sterile
swab, or a sterilized wire loop. Each device is simply a means of spreading the bacteria,
most commonly in a simple back-and-forth motion, across the plate.
