Two opposite forces operating in growth and development of every population. One of them has ability to reproduce at a given rate. The opposing force is

Options

A. biotic potential
B. migration
C. vital index
D. environmental resistance

Answer

To answer the question about the two opposing forces operating in the growth and development of every population, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the First Force**: The first force mentioned in the question is the ability of a species to reproduce at a given rate. This is known as **biotic potential**. Biotic potential refers to the maximum reproductive capacity of an organism under optimal environmental conditions, where resources are abundant.

2. **Identify the Opposing Force**: The question asks for the opposing force to biotic potential. This opposing force is known as **environmental resistance**. Environmental resistance encompasses all the factors that limit the growth of a population, preventing it from reaching its biotic potential.

3. **Explain Environmental Resistance**: Environmental resistance includes various biotic and abiotic factors such as:
- **Predators**: Organisms that hunt and consume other organisms.
- **Diseases**: Illnesses that can reduce population numbers.
- **Competition**: The struggle for limited resources among individuals of the same or different species.
- **Limited Resources**: Availability of food, water, and shelter.

4. **Conclusion**: In summary, while biotic potential represents the capacity for growth under ideal conditions, environmental resistance acts as a limiting factor that prevents populations from growing indefinitely. Therefore, the correct answer to the question is **environmental resistance**.

### Final Answer:
The opposing force to the ability to reproduce at a given rate (biotic potential) is **environmental resistance**.

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