Certified Professional Food Safety (CP-FS) Practice Exam

What role do time and temperature play in the Lag Phase?

1. They speed up bacterial growth.

2. They help keep bacteria in a less dangerous state.

3. They have no impact on bacterial growth.

4. They eliminate bacterial presence.

The correct answer is: They help keep bacteria in a less dangerous state.

Time and temperature are critical factors during the Lag Phase of bacterial growth. During this phase, bacteria are adapting to their new environment before they enter the exponential growth phase. The conditions of time and temperature directly influence the metabolic activities of the bacteria, as they acclimate and prepare for growth. When bacteria are kept at appropriate temperatures, their metabolism slows down, which helps maintain them in a less dangerous state compared to being in environments that promote rapid growth. For instance, if the temperature is too high, it can lead to more rapid growth or spoilage, while a lower temperature can inhibit harmful bacterial activity, allowing time for adaptation. Therefore, during the Lag Phase, the appropriate control of time and temperature can prevent bacteria from causing foodborne illnesses initially by keeping them in a less active state as they acclimate. In contrast, options discussing the elimination of bacterial presence or indicating that temperature and time have no impact are misleading, as they do play a significant role in bacterial behavior during this phase. Additionally, while extreme conditions might speed up growth, this typically refers to the exponential phase rather than the Lag Phase, where the focus is on adaptation rather than multiplication.