Which of the following is the characteristics of a biological community ?

Options

A. Stratification
B. Natality
C. Mortality
D. Sex ratio

Answer

To determine the characteristics of a biological community, we need to analyze the options provided and understand the definition of a biological community.

### Step-by-Step Solution:

1. **Understanding Biological Community**: A biological community is defined as a group of different species that live together in a specific area and interact with each other. They can exist independently but also engage in various interactions.

2. **Evaluating the Options**:
- **Option 1: Stratification**: This refers to the layering of different species within a community, often seen in ecosystems like forests where different species occupy different layers (e.g., canopy, understory). This is indeed a characteristic of a biological community.

- **Option 2: Natality**: This term refers to the birth rate within a population. While it is important for population dynamics, it does not specifically describe a characteristic of a biological community as a whole.

- **Option 3: Mortality**: Similar to natality, mortality refers to the death rate within a population. Again, this is more about population dynamics rather than a defining characteristic of a biological community.

- **Option 4: Sex Ratio**: This indicates the ratio of males to females in a population. While it can be relevant to the population structure, it does not define a biological community.

3. **Conclusion**: Based on the analysis, the only option that represents a characteristic of a biological community is **Stratification** (Option 1). The other options pertain to population dynamics rather than defining features of a community.

### Final Answer:
The characteristic of a biological community is **Stratification** (Option 1).