Microbiology 2100 Exam 2 with correct
answers
What does microbial growth refer to? - ** VERIFIED ANSWERS **✔✔numbers not size
What is an example of microbial growth? - ** VERIFIED ANSWERS **✔✔Binary fission
What is generation time? - ** VERIFIED ANSWERS **✔✔Time required for microbes to divide
How often can human pathogens divide and how much? - ** VERIFIED ANSWERS **✔✔Every 20-
30 minutes, double in numbers
How long of a period does generation time occur? - ** VERIFIED ANSWERS **✔✔Usually occurs in
short period of time
Whenever bacteria are introduced into a new environment they undergo or follow a - ** VERIFIED
ANSWERS **✔✔growth curve
What are the phases of the growth curve in order? - ** VERIFIED ANSWERS **✔✔Lag
Log/Exponential Growth
Stationary
Death/Decline
What happens during the Lag phase? - ** VERIFIED ANSWERS **✔✔A new environment— some
DNA and RNA synthesizes but there is little to no cell division
What happens during Log/Exponential Growth? - ** VERIFIED ANSWERS **✔✔Max cell
replication
, Which phase is most sensitive to antibiotics and which one especially? - ** VERIFIED ANSWERS
**✔✔Log/Exponential; penicillin
What is the stationary phase a result of? - ** VERIFIED ANSWERS **✔✔Decreased availability of
nutrients
Which phase is toxin production greatest? - ** VERIFIED ANSWERS **✔✔Stationary
During the stationary phase, what is the relationship between the death rate and multiplication rate?
- ** VERIFIED ANSWERS **✔✔Death rate = multiplication rate
During the death/decline phase, what is the relationship between cell death and the multiplication
rate? - ** VERIFIED ANSWERS **✔✔Cell death exceeds the multiplication rate
What accelerates cell death in all phases of the growth curve? - ** VERIFIED ANSWERS **✔✔Heat
and disinfectants
In nature and in the human body, bacteria can occur in 2 forms: - ** VERIFIED ANSWERS
**✔✔Planktonic and biofilms
What is planktonic? Examples? - ** VERIFIED ANSWERS **✔✔free floating
ex) water, saliva, infection in blood, etc
What are biofilms and where can they form? - ** VERIFIED ANSWERS **✔✔Bacteria attached to a
surface and to each other and form a multilayer of cells
ex) form on heart valves, joint replacement, etc
Which form of bacteria can form complex microbial communities? - ** VERIFIED ANSWERS
**✔✔Biofilms
answers
What does microbial growth refer to? - ** VERIFIED ANSWERS **✔✔numbers not size
What is an example of microbial growth? - ** VERIFIED ANSWERS **✔✔Binary fission
What is generation time? - ** VERIFIED ANSWERS **✔✔Time required for microbes to divide
How often can human pathogens divide and how much? - ** VERIFIED ANSWERS **✔✔Every 20-
30 minutes, double in numbers
How long of a period does generation time occur? - ** VERIFIED ANSWERS **✔✔Usually occurs in
short period of time
Whenever bacteria are introduced into a new environment they undergo or follow a - ** VERIFIED
ANSWERS **✔✔growth curve
What are the phases of the growth curve in order? - ** VERIFIED ANSWERS **✔✔Lag
Log/Exponential Growth
Stationary
Death/Decline
What happens during the Lag phase? - ** VERIFIED ANSWERS **✔✔A new environment— some
DNA and RNA synthesizes but there is little to no cell division
What happens during Log/Exponential Growth? - ** VERIFIED ANSWERS **✔✔Max cell
replication
, Which phase is most sensitive to antibiotics and which one especially? - ** VERIFIED ANSWERS
**✔✔Log/Exponential; penicillin
What is the stationary phase a result of? - ** VERIFIED ANSWERS **✔✔Decreased availability of
nutrients
Which phase is toxin production greatest? - ** VERIFIED ANSWERS **✔✔Stationary
During the stationary phase, what is the relationship between the death rate and multiplication rate?
- ** VERIFIED ANSWERS **✔✔Death rate = multiplication rate
During the death/decline phase, what is the relationship between cell death and the multiplication
rate? - ** VERIFIED ANSWERS **✔✔Cell death exceeds the multiplication rate
What accelerates cell death in all phases of the growth curve? - ** VERIFIED ANSWERS **✔✔Heat
and disinfectants
In nature and in the human body, bacteria can occur in 2 forms: - ** VERIFIED ANSWERS
**✔✔Planktonic and biofilms
What is planktonic? Examples? - ** VERIFIED ANSWERS **✔✔free floating
ex) water, saliva, infection in blood, etc
What are biofilms and where can they form? - ** VERIFIED ANSWERS **✔✔Bacteria attached to a
surface and to each other and form a multilayer of cells
ex) form on heart valves, joint replacement, etc
Which form of bacteria can form complex microbial communities? - ** VERIFIED ANSWERS
**✔✔Biofilms
