Geographic limit within which a population exists is called

Options

A. Biome
B. Ecosystem
C. Niche
D. Habitate

Answer

To solve the question, "Geographic limit within which a population exists is called," we need to analyze the given options one by one.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the term that describes the geographic limit within which a specific population exists.

2. **Analyzing the Options**:
- **Option 1: Biome**: A biome is a large geographical area characterized by specific climate conditions and the types of plants and animals that live there. It encompasses multiple ecosystems, so it does not refer to a single population. Therefore, this option is incorrect.

- **Option 2: Ecosystem**: An ecosystem includes all the living organisms (plants, animals, microbes) in a particular area, along with the non-living components (air, water, soil) that interact with them. While ecosystems can contain multiple populations, they do not specifically refer to the geographic limit of a single population. Thus, this option is also incorrect.

- **Option 3: Niche**: A niche refers to the role or function of an organism within its environment, including its interactions with other organisms. It encompasses the species' habitat, resource use, and interactions, but does not define a geographic limit for a single population. Hence, this option is incorrect as well.

- **Option 4: Habitat**: A habitat is defined as the natural environment in which a particular species or population lives. It is the geographic limit within which a single population exists. This makes habitat the correct answer to the question.

3. **Conclusion**: Based on the analysis, the correct answer is **Option 4: Habitat**.

### Final Answer:
The geographic limit within which a population exists is called **Habitat**.