Exponential growth is shown during

Options

A. Lag phase
B. Log phase
C. Maturation phase
D. Senescence phase.

Answer

### Step-by-Step Solution

1. **Understanding Phases of Bacterial Growth**: Bacterial growth is divided into four distinct phases: lag phase, log phase, maturation (stationary) phase, and senescence (death) phase. Each phase has unique characteristics that affect the growth of bacteria.

2. **Lag Phase**: In the lag phase, there is very little or no growth. This is because bacteria are adjusting to their environment and synthesizing necessary biochemicals and nutrients. Therefore, this phase does not exhibit exponential growth.

3. **Log Phase**: The log phase is where exponential growth occurs. During this phase, the number of bacterial cells doubles at an exponential rate. The bacteria have adjusted to the environmental conditions, leading to rapid division and maximum growth.

4. **Maturation (Stationary) Phase**: In this phase, the rate of cell division equals the rate of cell death. As a result, the population remains stable, and there is no exponential growth.

5. **Senescence (Death) Phase**: This phase is characterized by a decline in the bacterial population due to a lack of nutrients and the accumulation of toxic substances. Hence, there is no growth in this phase.

6. **Conclusion**: Based on the analysis of the phases, exponential growth is specifically shown during the **log phase**.

### Final Answer
Exponential growth is shown during the **log phase**.

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