Growth plotted against time gives a

Options

A. Parabolic curve
B. Sigmoid curve
C. Upright line
D. Horizontal line

Answer

To solve the question "Growth plotted against time gives a:", we will analyze the options provided and understand the concept of growth phases in biological organisms.

### Step-by-Step Solution:

1. **Understanding Growth Phases**:
- Biological growth can be divided into distinct phases: lag phase, log (exponential) phase, stationary phase, and death phase. Each of these phases represents a different rate of growth.

2. **Lag Phase**:
- In the lag phase, the growth rate is slow as the cells are preparing for division. This phase is characterized by little to no increase in cell number.

3. **Log Phase**:
- The log phase is where the growth rate accelerates. Cells are actively dividing, and the population increases exponentially. This is the phase where maximum growth occurs.

4. **Stationary Phase**:
- In the stationary phase, the growth rate slows down and stabilizes. The number of new cells created is equal to the number of cells dying, resulting in a constant population size.

5. **Death Phase**:
- In the death phase, the number of dying cells exceeds the number of new cells being produced, leading to a decline in the overall population.

6. **Plotting Growth Against Time**:
- When we plot growth (on the y-axis) against time (on the x-axis), the resulting graph reflects these phases. The curve starts slowly during the lag phase, rises steeply during the log phase, levels off during the stationary phase, and then declines in the death phase.

7. **Identifying the Curve Type**:
- The resulting graph is an S-shaped curve, known as a sigmoid curve. This shape reflects the different phases of growth over time.

8. **Conclusion**:
- Therefore, when growth is plotted against time, it gives a sigmoid curve.

### Final Answer:
The correct answer is: **Sigmoid curve** (Option 2).