New York City Food Protection Practice Test

Which of the following describes the Stationary phase of bacterial growth?

1. Bacterial death rate decreases

2. Growth rate exceeds death rate

3. Birth and death rates are approximately equal

4. Rapid population increase

The correct answer is: Birth and death rates are approximately equal

The stationary phase of bacterial growth is characterized by a balance between the birth and death rates of the bacteria. During this phase, the population stabilizes as the number of new cells being produced is roughly equal to the number of cells dying. This is often due to the depletion of nutrients and accumulation of waste products, which limit further growth. It is a critical phase where the environment's carrying capacity is reached, leading to this equilibrium. This understanding highlights why the other options do not accurately describe the stationary phase. During the stationary phase, bacterial death rates do not decrease drastically, nor does the growth rate exceed the death rate, which would indicate a different phase, such as the exponential phase. Additionally, a rapid population increase would be typical of the log (exponential) phase, not the stationary phase where the population size remains stable.