BIOL 2460 Chapter 9 Exam 2026
Questions and Answers
Binary Fission - Answer -Most common form of bacteria reproduction
4 Basic Steps:
1. Growth of cell size and increase in cell components
2. Replication of DNA
3. Division of the cytoplasm (cytokinesis)
4. Septum formation and division of daughter cells
Growth Curve Pattern - Answer -1. Lag phase
2. Log (exponential) phase
3. Stationary phase
4. Death phase
Lag Phase - Answer -Inoculum cells added and adjust to culture medium; no
change in population
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, - Initial cell numbers do not change
- Cells grow larger; metabolically active
- Damaged or shocked cells undergo repair
- Duration of the lag phase determined by many factors including: genetic make-
up, media composition, initial inoculum size
Log (exponential) phase - Answer -Binary fission occurs; Cell replication > cell
death
- Generation time is genetically determined (intrinsic growth rate)
- Time vs. # of cells is exponential (semilog displays linear)
- Constant growth & uniform metabolism; good for industrial applications
- Most susceptible to disinfectants and antibiotics that affect protein, DNA, and
cell-wall synthesis
Stationary Phase - Answer -Resources become depleted
Cell replication = Cell death
- Waste accumulates; nutrients gradually used up
- Culture density is constant
- Cells enter survival mode; synthesis slows; less susceptible to antibiotics
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Questions and Answers
Binary Fission - Answer -Most common form of bacteria reproduction
4 Basic Steps:
1. Growth of cell size and increase in cell components
2. Replication of DNA
3. Division of the cytoplasm (cytokinesis)
4. Septum formation and division of daughter cells
Growth Curve Pattern - Answer -1. Lag phase
2. Log (exponential) phase
3. Stationary phase
4. Death phase
Lag Phase - Answer -Inoculum cells added and adjust to culture medium; no
change in population
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, - Initial cell numbers do not change
- Cells grow larger; metabolically active
- Damaged or shocked cells undergo repair
- Duration of the lag phase determined by many factors including: genetic make-
up, media composition, initial inoculum size
Log (exponential) phase - Answer -Binary fission occurs; Cell replication > cell
death
- Generation time is genetically determined (intrinsic growth rate)
- Time vs. # of cells is exponential (semilog displays linear)
- Constant growth & uniform metabolism; good for industrial applications
- Most susceptible to disinfectants and antibiotics that affect protein, DNA, and
cell-wall synthesis
Stationary Phase - Answer -Resources become depleted
Cell replication = Cell death
- Waste accumulates; nutrients gradually used up
- Culture density is constant
- Cells enter survival mode; synthesis slows; less susceptible to antibiotics
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
