Rate of natural increase' is :

Options

A. r
B. k
C. b
D. d

Answer

To answer the question "Rate of natural increase is:", we need to understand the concept of natural increase in populations, particularly in the context of exponential growth. Here’s a step-by-step breakdown of the solution:

### Step 1: Define Rate of Natural Increase
The rate of natural increase refers to the growth rate of a population, which is determined by the difference between the birth rate and the death rate within a given time period.

### Step 2: Understand Exponential Growth
In the context of exponential growth, the population grows rapidly when resources are unlimited. This is a theoretical model where the population can increase without constraints.

### Step 3: Identify Key Terms
- **Biotic Potential**: This is the maximum reproductive capacity of an organism under optimal environmental conditions. It is often represented by the symbol "R".
- **Birth Rate (B)**: The number of live births per 1,000 individuals in a population per year.
- **Death Rate (D)**: The number of deaths per 1,000 individuals in a population per year.

### Step 4: Calculate Rate of Natural Increase
The rate of natural increase (R) can be calculated using the formula:
\[ R = B - D \]
Where:
- R = Rate of natural increase
- B = Birth rate
- D = Death rate

### Step 5: Relate to Population Growth
In the exponential growth model, the change in population size over time can be represented by the equation:
\[ \frac{dN}{dt} = R \times N \]
Where:
- \( \frac{dN}{dt} \) = Change in population size over time
- N = Current population size

### Conclusion
Thus, the rate of natural increase is essentially the biotic potential of a population, which is calculated by subtracting the per capita death rate from the per capita birth rate.