Food Microbiology exam queries and
answers graded A+
FSIS (Food Safety and Inspection Service) is the agency in charge of HACCP regulation for seafood
and juice products
T or F - ANS✅✅False
E. coli and coliforms can be used as indicator microorganisms because:
a. Their growth and numbers have a direct negative correlation with product quality
b. Their enumeration period is usually fast, and colonies can be counted after 1 hour of incubation
c. Their growth and numbers have a direct positive correlation with product quality
d. they are not good indicators. Your instructor just loves E. coli - ANS✅✅c. Their growth and
numbers have a direct positive correlation with product quality
Agricultural water and biological soil amendments are requirements for which FSMA rule:
a. Imported Food
b. Preventive Controls for Food for Animal
c. Preventive Controls for Human Food
d. Produce Safety
e. It is not required by and FSMA rule - ANS✅✅d. Produce Saftey
The ability of a given cell to grow size of a macroscopic colony depends on many things such as? -
ANS✅✅the cells physiological state, the growth medium used, incubation temperature
How many cells are there in one CFU?
a. 10^19 cells
b. 1 cell
c. 79,000 cells
d. we can't say an exact number; the assumption is that one colony originates from one cell -
ANS✅✅d. we can't say an exact number; the assumption is that one colony originates from one
cell
,You are given and enriched sample known to contain a specific bacterial pathogen. You have been
asked to perform a test for confirmation of the target pathogen. You know that your sample
contains less than 10^2 CFU/g of that pathogen. Which method will be more accurate to confirm this
microorganism?
a. Immunological method
b. Molecular method
c. Standard plating
d. Gram stain - ANS✅✅b. Molecular method
The main purpose of fermentation for microorganisms is:
a. Make energy/energy conservation
b. Obtain nutrients
c. Change texture of foods
d. Decrease pH of foods - ANS✅✅a. Make energy/energy conservation
A nationwide collaboration that enables all levels of public health (local, state, territorial, federal,
and international) to share notifiable disease related health information. Public health uses this
information to monitor, control and prevent the occurrence and spread of state-reportable and
nationally notifiable infectious and noninfectious diseases and conditions. This refers to:
a. HACCP
b. Healthy People 2020
c. FoodNet
d. National Notifiable Diseases Surveillance System - ANS✅✅d. National Notifiable Diseases
Surveillance System
The CFU per gram values derived from plate counts are also influenced by? - ANS✅✅intrinsic
factors
MPN methods (most probable number) are used to? - ANS✅✅estimate the MPN of organisms in a
sample when only low levels <30 CFU/ml are present.
There is a zero tolerance for which two bacteria in ready to eat foods? - ANS✅✅E. coli O157:H7
and Salmonella L. monocytigenes and listeria monocytogenes
, What do growth curve graphs represent? - ANS✅✅the state of microbial population rather than
individual microbes
In a growth curve graph both the lag phase and stationary phase of growth represent what? -
ANS✅✅Represent periods when the growth rate equals the death rate to produce no net change
in cell numbers.
During the lag phase what do the cells do? - ANS✅✅cells adjust to their environment by turning
genes on or off, replicating their genes and differentiating into vegetative cells.
What happens to cells in the log/exponential phase? - ANS✅✅Bacteria reproduce by binary
fission.
(one cell divided into two cells that divide into four and then into eight and so on)
What are the phases in a growth curve graph? - ANS✅✅Lag, Log, Stationary and death
What are some environmental effects on microbial growth? - ANS✅✅temperature, oxygen, ph
and water availability
What are some microbial growth nutrients? - ANS✅✅Macronutrients and Micronutrients
List some Macronutrients. - ANS✅✅Carbon, Nitrogen, Iron, Phosphate, Potassium, Magnesium
and Calcium
List some Micronutrients - ANS✅✅Chromium, Cobalt, Copper, zinc,manganese
What are some microbial growth factors? - ANS✅✅Vitamins, Amino Acids,Purines and Pyrimidines
Bacteria can be classified according to how temperature influences growth.
What are psychrophiles? - ANS✅✅Cold loving bacteria with optimum growth temperature of-20C
to +10C
Bacteria can be classified according to how temperature influences growth.
What are psychrotrophs - ANS✅✅cold tolerant bacteria with optimum growth temp of 15 to 20C
answers graded A+
FSIS (Food Safety and Inspection Service) is the agency in charge of HACCP regulation for seafood
and juice products
T or F - ANS✅✅False
E. coli and coliforms can be used as indicator microorganisms because:
a. Their growth and numbers have a direct negative correlation with product quality
b. Their enumeration period is usually fast, and colonies can be counted after 1 hour of incubation
c. Their growth and numbers have a direct positive correlation with product quality
d. they are not good indicators. Your instructor just loves E. coli - ANS✅✅c. Their growth and
numbers have a direct positive correlation with product quality
Agricultural water and biological soil amendments are requirements for which FSMA rule:
a. Imported Food
b. Preventive Controls for Food for Animal
c. Preventive Controls for Human Food
d. Produce Safety
e. It is not required by and FSMA rule - ANS✅✅d. Produce Saftey
The ability of a given cell to grow size of a macroscopic colony depends on many things such as? -
ANS✅✅the cells physiological state, the growth medium used, incubation temperature
How many cells are there in one CFU?
a. 10^19 cells
b. 1 cell
c. 79,000 cells
d. we can't say an exact number; the assumption is that one colony originates from one cell -
ANS✅✅d. we can't say an exact number; the assumption is that one colony originates from one
cell
,You are given and enriched sample known to contain a specific bacterial pathogen. You have been
asked to perform a test for confirmation of the target pathogen. You know that your sample
contains less than 10^2 CFU/g of that pathogen. Which method will be more accurate to confirm this
microorganism?
a. Immunological method
b. Molecular method
c. Standard plating
d. Gram stain - ANS✅✅b. Molecular method
The main purpose of fermentation for microorganisms is:
a. Make energy/energy conservation
b. Obtain nutrients
c. Change texture of foods
d. Decrease pH of foods - ANS✅✅a. Make energy/energy conservation
A nationwide collaboration that enables all levels of public health (local, state, territorial, federal,
and international) to share notifiable disease related health information. Public health uses this
information to monitor, control and prevent the occurrence and spread of state-reportable and
nationally notifiable infectious and noninfectious diseases and conditions. This refers to:
a. HACCP
b. Healthy People 2020
c. FoodNet
d. National Notifiable Diseases Surveillance System - ANS✅✅d. National Notifiable Diseases
Surveillance System
The CFU per gram values derived from plate counts are also influenced by? - ANS✅✅intrinsic
factors
MPN methods (most probable number) are used to? - ANS✅✅estimate the MPN of organisms in a
sample when only low levels <30 CFU/ml are present.
There is a zero tolerance for which two bacteria in ready to eat foods? - ANS✅✅E. coli O157:H7
and Salmonella L. monocytigenes and listeria monocytogenes
, What do growth curve graphs represent? - ANS✅✅the state of microbial population rather than
individual microbes
In a growth curve graph both the lag phase and stationary phase of growth represent what? -
ANS✅✅Represent periods when the growth rate equals the death rate to produce no net change
in cell numbers.
During the lag phase what do the cells do? - ANS✅✅cells adjust to their environment by turning
genes on or off, replicating their genes and differentiating into vegetative cells.
What happens to cells in the log/exponential phase? - ANS✅✅Bacteria reproduce by binary
fission.
(one cell divided into two cells that divide into four and then into eight and so on)
What are the phases in a growth curve graph? - ANS✅✅Lag, Log, Stationary and death
What are some environmental effects on microbial growth? - ANS✅✅temperature, oxygen, ph
and water availability
What are some microbial growth nutrients? - ANS✅✅Macronutrients and Micronutrients
List some Macronutrients. - ANS✅✅Carbon, Nitrogen, Iron, Phosphate, Potassium, Magnesium
and Calcium
List some Micronutrients - ANS✅✅Chromium, Cobalt, Copper, zinc,manganese
What are some microbial growth factors? - ANS✅✅Vitamins, Amino Acids,Purines and Pyrimidines
Bacteria can be classified according to how temperature influences growth.
What are psychrophiles? - ANS✅✅Cold loving bacteria with optimum growth temperature of-20C
to +10C
Bacteria can be classified according to how temperature influences growth.
What are psychrotrophs - ANS✅✅cold tolerant bacteria with optimum growth temp of 15 to 20C
