MCB3020: EXAM 2- Bacusmo UF Final
Questions and All Correct Answers
2026 Updated.
What is the most common mechanism for bacterial cell division? - Answer Binary Fission
List the four steps of the mechanism above. - Answer 1. Elongation of the cell
2. Replication of the chromosome
3. Separation of the chromosomes into the two parts of the cell
4. Formation of septum in the middle (Cytokinesis, or septation)
Define 'Origin of replication'. - Answer Where replication begins
How many Origins of replication do bacterial chromosomes have? - Answer One
What is Cytokinesis? Include a brief overview of its four steps. - Answer The division of the
cell into two via formation of a cross wall between the two daughter cells.
Define the following terms and their role in cell division:
Penicillin-binding protein (PBP): - Answer Group of proteins that hydrolyze bonds in existing
peptidoglycan strands and link together new strands.
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM): - Answer Major components
of peptidoglycan that bind to a membrane protein called bactoprenol.
Autolysins: - Answer Degrade polypeptide where new units are to be added, and the new
NAM-NAG units can then be inserted into the peptidoglycan layer.
What is crescentin? - Answer A homologue of eukaryotic intermediate filaments
What are the other forms of asexual reproduction? Define each - Answer -Budding: Budding
off daughter cells; seen in Listeria monocytogenes
-Baeocyte formation (multiple fission): Multiple rounds of cell division; seen in Cyanobacteria
-Spore formation: Form multinucleoid filaments that ultimately divide to produce spores with a
single nucleus.
,Know the Bacterial Growth Curve - Answer lag,log,stationary,dead
List and define each phase of the above curve. - Answer -Lag Phase: No net growth because,
although the nutrients are abundant, the bacteria are adjusting to new conditions.
-Log (Exponential) Phase: Nutrients are abundant, and bacteria divide at their highest rate.
-Stationary Phase: Number of viable microorganisms is stable because the nutrients level off
and waste products accumulate
-Death Phase: Nutrients are depleted, and levels of waste products and toxins are high, so the
number of viable microorganisms decreases
-Long-term Stationary Phase: Nutrients are depleted, and waves of genetic variants come and
go
True or False: When nutrient levels are low, the limitation of microbial growth occurs as a result
of the saturation of transport proteins for nutrient uptake. - Answer False; should be when
levels are high
What is generation time (GT)? - Answer The time it takes the population to double
What phase is it best to calculate GT? - Answer Log Phase (aka Exponential Phase)
True or False: Cells typically exist in aqueous conditions. - Answer true
Define hypertonic and hypotonic. - Answer Hypertonic: One solution has higher
concentration of solutes than another
Hypotonic: One solution has lower concentration of solutes than another
If a cell is in a hypertonic solution it will ____, while in a hypotonic solution it will ____. - Answer
Shrink; Burst
What are the three distinct cardinal growth temperatures for organisms? - Answer 1.
Minimum growth temperature: Lowest temperature at which an organism can grow and survive
2. Maximum growth temperature: Highest temperature at which an organism can grow and
survive
3. Optimal growth temperature: Most suitable temperature for bacterial growth
Know the following microbial adaptations. Define each.
Halophiles - Answer Grow best in extremely salty environments
, b. Xerophiles: - Answer Grow best in dry conditions
c. Psychrophiles: - Answer Grow between 0C and 20C - refrigeration temperatures
d. Mesophiles: - Answer Grow between 20C and 45C
e. Thermophiles: - Answer Grow between 55C and 85C
f. Hyperthermophiles: - Answer Grow between 85C and 113C - usually archaens
g. Aerobe: - Answer Grow in presence of atmospheric oxygen
h. Obligate Aerobes: - Answer Require oxygen for growth and die without it
i. Anaerobe: - Answer Grow in absence of oxygen
j. Obligate Anaerobes: - Answer Cannot survive in presence of oxygen
k. Facultative Anaerobes: - Answer Grow better with oxygen than without it (not needed)
l. Barotolerant: - Answer Survive increased pressures
True or False: Most human pathogens are Mesophiles. - Answer TRUE
When does food spoilage occur? - Answer Occurs when nutritional value, texture, or flavor of
food is changed due to presence of food spoilage organisms.
True or False: Only a select few of our foods contain food spoilage microorganisms. - Answer
False; All of our foods do
What are the three most common food spoilage organisms? - Answer Bacteria, yeasts, and
molds
How is food spoilage controlled? - Answer By manipulating temperature
Questions and All Correct Answers
2026 Updated.
What is the most common mechanism for bacterial cell division? - Answer Binary Fission
List the four steps of the mechanism above. - Answer 1. Elongation of the cell
2. Replication of the chromosome
3. Separation of the chromosomes into the two parts of the cell
4. Formation of septum in the middle (Cytokinesis, or septation)
Define 'Origin of replication'. - Answer Where replication begins
How many Origins of replication do bacterial chromosomes have? - Answer One
What is Cytokinesis? Include a brief overview of its four steps. - Answer The division of the
cell into two via formation of a cross wall between the two daughter cells.
Define the following terms and their role in cell division:
Penicillin-binding protein (PBP): - Answer Group of proteins that hydrolyze bonds in existing
peptidoglycan strands and link together new strands.
N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM): - Answer Major components
of peptidoglycan that bind to a membrane protein called bactoprenol.
Autolysins: - Answer Degrade polypeptide where new units are to be added, and the new
NAM-NAG units can then be inserted into the peptidoglycan layer.
What is crescentin? - Answer A homologue of eukaryotic intermediate filaments
What are the other forms of asexual reproduction? Define each - Answer -Budding: Budding
off daughter cells; seen in Listeria monocytogenes
-Baeocyte formation (multiple fission): Multiple rounds of cell division; seen in Cyanobacteria
-Spore formation: Form multinucleoid filaments that ultimately divide to produce spores with a
single nucleus.
,Know the Bacterial Growth Curve - Answer lag,log,stationary,dead
List and define each phase of the above curve. - Answer -Lag Phase: No net growth because,
although the nutrients are abundant, the bacteria are adjusting to new conditions.
-Log (Exponential) Phase: Nutrients are abundant, and bacteria divide at their highest rate.
-Stationary Phase: Number of viable microorganisms is stable because the nutrients level off
and waste products accumulate
-Death Phase: Nutrients are depleted, and levels of waste products and toxins are high, so the
number of viable microorganisms decreases
-Long-term Stationary Phase: Nutrients are depleted, and waves of genetic variants come and
go
True or False: When nutrient levels are low, the limitation of microbial growth occurs as a result
of the saturation of transport proteins for nutrient uptake. - Answer False; should be when
levels are high
What is generation time (GT)? - Answer The time it takes the population to double
What phase is it best to calculate GT? - Answer Log Phase (aka Exponential Phase)
True or False: Cells typically exist in aqueous conditions. - Answer true
Define hypertonic and hypotonic. - Answer Hypertonic: One solution has higher
concentration of solutes than another
Hypotonic: One solution has lower concentration of solutes than another
If a cell is in a hypertonic solution it will ____, while in a hypotonic solution it will ____. - Answer
Shrink; Burst
What are the three distinct cardinal growth temperatures for organisms? - Answer 1.
Minimum growth temperature: Lowest temperature at which an organism can grow and survive
2. Maximum growth temperature: Highest temperature at which an organism can grow and
survive
3. Optimal growth temperature: Most suitable temperature for bacterial growth
Know the following microbial adaptations. Define each.
Halophiles - Answer Grow best in extremely salty environments
, b. Xerophiles: - Answer Grow best in dry conditions
c. Psychrophiles: - Answer Grow between 0C and 20C - refrigeration temperatures
d. Mesophiles: - Answer Grow between 20C and 45C
e. Thermophiles: - Answer Grow between 55C and 85C
f. Hyperthermophiles: - Answer Grow between 85C and 113C - usually archaens
g. Aerobe: - Answer Grow in presence of atmospheric oxygen
h. Obligate Aerobes: - Answer Require oxygen for growth and die without it
i. Anaerobe: - Answer Grow in absence of oxygen
j. Obligate Anaerobes: - Answer Cannot survive in presence of oxygen
k. Facultative Anaerobes: - Answer Grow better with oxygen than without it (not needed)
l. Barotolerant: - Answer Survive increased pressures
True or False: Most human pathogens are Mesophiles. - Answer TRUE
When does food spoilage occur? - Answer Occurs when nutritional value, texture, or flavor of
food is changed due to presence of food spoilage organisms.
True or False: Only a select few of our foods contain food spoilage microorganisms. - Answer
False; All of our foods do
What are the three most common food spoilage organisms? - Answer Bacteria, yeasts, and
molds
How is food spoilage controlled? - Answer By manipulating temperature
