Select the incorrect statement among the following:

Options

A. Increase in growth per unit time is growth rate
B. A sigmoid growth curve is a characteristic of most living organisms in their natural environment
C. Rate of growth is constant during geometrical growth
D. Exponential phase is also called as log phase

Answer

To solve the question, we need to identify the incorrect statement among the given options related to plant growth and development. Let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding Growth Rate**:
- The first statement mentions that "increase in the growth per unit time is growth rate."
- This statement is correct as growth rate is defined as the change in size or mass of an organism over a specific time period.

2. **Sigmoid Growth Curve**:
- The second statement states that "a sigmoid growth curve is characteristic of most living organisms in their natural environment."
- This statement is also correct. The sigmoid curve (S-shaped) represents the typical growth pattern of organisms, where growth is slow initially, accelerates during the middle phase, and then levels off as it reaches carrying capacity.

3. **Rate of Growth During Geometric Growth**:
- The third statement claims that "the rate of growth is constant during the geometric growth."
- This statement is incorrect. In geometric growth, the rate of growth is not constant; it increases exponentially over time.

4. **Exponential Phase**:
- The fourth statement mentions that "the exponential phase is also called the log phase."
- This statement is correct. The exponential phase, where growth accelerates, is indeed referred to as the log phase in the context of population growth.

### Conclusion:
Based on the analysis, the incorrect statement among the options is the third statement: "the rate of growth is constant during the geometric growth."

### Final Answer:
The incorrect statement is: **"The rate of growth is constant during the geometric growth."**

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