Population density is the

Options

A. Number of species in an ecosystem
B. Number of individuals of a species per unit area
C. Number of births reported in a year
D. Number of individuals of a species in an ecosystem

Answer

**Step-by-Step Text Solution:**

1. **Understanding Population Density**: Population density is a term used in ecology to describe how many individuals of a particular species are present in a specific area.

2. **Defining the Concept**: The correct definition of population density is "the number of individuals of a species per unit area." This means that if you take a defined area (like a square meter or square kilometer), population density tells you how many individuals of a specific species live within that area.

3. **Examples**: For instance, if there are 100 individuals of a species living in an area of 100 square meters, the population density would be 1 individual per square meter (100 individuals / 100 square meters = 1 individual/m²).

4. **Distinguishing from Related Terms**: It’s important to differentiate population density from other ecological terms:
- **Biodiversity**: Refers to the variety of life in a particular ecosystem.
- **Crude Birth Rate**: Refers to the number of births in a population over a specific period (usually a year).
- **Species Richness**: Refers to the number of different species present in an ecosystem.

5. **Conclusion**: Therefore, the correct definition of population density is "the number of individuals of a species per unit area."

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