Question 1
0 / 0 pts
What is another name for a liquid growth media, and what are the basic
components?
Your Answer:
Growth media in a liquid form is
... [Show More] often referred to as nutrient broth. Its
composition consists primarily of essential ingredients such as a rich source of
sugars, amino acids, and vitamins. A nutrient broth provides the microbe with a
source of carbon/energy, which encourages its expansion.
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.
Question 2
0 / 0 pts
What is selective media?
Your Answer:
Selective media only allows for the growth of certain microbes while restricting
the growth of all others.
Selective media allows for only the growth of certain microbes while
restricting the growth of all others.
Question 3
0 / 0 pts
What is differential media?
Your Answer:
Differential media is used to differentiate between two (or more) related microbes.
Differential media is used to distinguish between two (or more) related
microbes.
Question 4
0 / 0 pts
What are the requirements of a fastidious microbe?
Your Answer:
A fastidious microbe is an organism with complex growth requirements such that
if absent it will not grow. Enriched media thus contain these specific and
essential nutrients required for the growth of a particular subset of
microorganisms.
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.
Question 5
0 / 0 pts
What is agar?
Your Answer:
Agar is liquid growth media that has had a hardening agent added to it. Agar is
created when a polysaccharide derived from seaweed extract is added to growth
media. Agar is used to create a solid, smooth surface on which microbes can
grow.
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.
Question 6
0 / 0 pts
True or False: LB agar is classified as a non-selective, differential media.
True
Correct!
False
LB agar is both a non-selective and non-differential media. LB agar is
often used to expand unknown microbial population because it
encourages microbial growth due to the presence of universal nutrients
(non-differential) and absence of restrictive factors (non-selective).
Question 7
0 / 0 pts
What are the three forms of hemolysis found on blood agar plates?
Your Answer:
Alpha hemolysis, beta hemolysis, and gamma hemolysis
Alpha (green), Beta (clear zones) and Gamma (white/tan). Microbes
capable of alpha hemolysis present with greenish-brown color colonies
due to the incomplete (partial) lysis of red blood cells. Beta hemolysis is
classified as the 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 designates the absence or lack of
hemolytic activity and the resulting colonies are often white/tan in color
growing on the red background color of the unaffected blood agar plate.
Question 8
0 / 0 pts
What is the primary purpose of Columbia CNA agar?
Your Answer:
As it suppresses the growth of Gram- bacteria, it is used for isolation of Gram+
bacteria.
As it suppresses the growth of Gram-negative bacteria CNA agar is,
therefore, used for isolation of Gram-positive microbes.
Question 9
0 / 0 pts
Name the type of plate derived from BAP that contains lysed red blood cells.
Your Answer:
Lysed RBCs are a primary component in the formulation of Chocolate agar.
Lysed red blood cells (RBCs) are a primary component in the formulation
of Chocolate agar.
Question 10
0 / 0 pts
Define the selective and differential abilities of a MacConkey agar plate.
Your Answer:
MacConkey agar is selective in that only Gram- microbes will grow on the agar. It
is also considered differential as it distinguishes between microbes capable of
fermenting lactose (red colonies) and those that are non-fermenters (white/tan
colonies).
MacConkey agar is selective in that only Gram-negative microbes will
grow on the agar—Gram [Show Less]