Which of the following is a major cause of loss of biodiversity ?

Options

A. Habitat loss and fragmentation
B. Over-exploitation
C. Alien species invasion
D. Co-extinction

Answer

To determine the major cause of loss of biodiversity from the given options, we can analyze each option step by step.

### Step-by-Step Solution

1. **Understanding Biodiversity Loss**: Biodiversity loss refers to the decline in the variety and variability of life forms on Earth. It can be caused by various factors, including habitat destruction, overexploitation, introduction of alien species, and co-extinction.

2. **Analyzing the Options**:
- **Option A: Habitat Loss and Fragmentation**: This refers to the destruction of natural habitats due to human activities such as urban development, agriculture, and industrialization. It is widely recognized as a primary driver of biodiversity loss because it directly impacts the living conditions of many species.

- **Option B: Overexploitation**: This involves the excessive use of species for resources (e.g., overfishing, logging). While it contributes to biodiversity loss, it is not as significant as habitat loss.

- **Option C: Alien Species Invasion**: This occurs when non-native species are introduced into an ecosystem, often leading to competition with native species. Although it can cause biodiversity loss, it is generally considered a secondary factor compared to habitat loss.

- **Option D: Co-extinction**: This is the extinction of one species leading to the extinction of another species that depends on it. While it plays a role in biodiversity loss, it is not a major cause.

3. **Conclusion**: After analyzing all the options, it is clear that **habitat loss and fragmentation** (Option A) is the major cause of biodiversity loss. This is due to the direct impact it has on the survival of numerous species by destroying their natural environments.

### Final Answer
The major cause of loss of biodiversity is **habitat loss and fragmentation**.

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