New York City Food Protection Practice Test

Which of the following is NOT one of the four phases of bacterial growth?

1. Log phase

2. Death phase

3. Growth phase

4. Stationary phase

The correct answer is: Growth phase

The four recognized phases of bacterial growth are the lag phase, log (or exponential) phase, stationary phase, and death (or decline) phase. Each of these phases describes a different stage in the growth cycle of bacteria as they adapt to their environment, reproduce, and ultimately face limitations due to depletion of resources or accumulation of waste products. The log phase is characterized by rapid cell division and exponential growth of the bacterial population. The stationary phase occurs when the growth rate slows and stabilizes due to nutrient depletion or accumulation of waste, resulting in a balance between cell division and cell death. The death phase follows when the number of dying cells exceeds that of new cells being produced, leading to a decrease in the overall population. The term "growth phase" is not a specific stage recognized in the standard bacterial growth model, making it an inaccurate choice in this context. It is often used informally to refer to either the log phase or the preceding lag phase, but it does not stand as a distinct phase on its own. Therefore, the correct answer identifies that growth phase does not fit within the established framework of bacterial growth phases.