Which phase of a sigmoid curve explains the initial phase of growth when growth rate is very slow?

Options

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

Answer

To answer the question regarding which phase of a sigmoid curve explains the initial phase of growth when the growth rate is very slow, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Sigmoid Curve**:
- The sigmoid curve represents the growth of an organism or population over time. It typically consists of three main phases: lag phase, log phase, and stationary phase.

2. **Identify the Phases**:
- **Lag Phase**: This is the initial phase where growth is very slow. Organisms are acclimatizing to their environment and are not yet fully utilizing available resources.
- **Log Phase**: Following the lag phase, this phase is characterized by rapid growth as resources become abundant and organisms begin to grow exponentially.
- **Stationary Phase**: In this phase, growth levels off as resources become limited, and the growth rate stabilizes.

3. **Focus on the Initial Phase**:
- The question specifically asks for the phase where the growth rate is very slow. This is clearly defined as the lag phase.

4. **Conclusion**:
- Therefore, the phase of the sigmoid curve that explains the initial phase of growth when the growth rate is very slow is the **lag phase**.

### Final Answer:
The correct answer is **lag phase** (Option B).

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