What is the main purpose or aim for conserving national parks, wildlife sanctuaries and biosphere reserve?

Explanation

### Step-by-Step Solution:

1. **Understanding Conservation**: The first step in answering the question is to understand what conservation means. Conservation refers to the protection and preservation of the natural environment and wildlife.

2. **Identifying What is Being Conserved**: The focus of conservation efforts is primarily on protecting various species, which can include both plants and animals. This is crucial for maintaining biodiversity.

3. **Recognizing Threatened Species**: Many species are threatened or endangered due to habitat loss, poaching, climate change, and other human activities. Conservation areas like national parks and wildlife sanctuaries specifically aim to protect these vulnerable species.

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