What is extent of biosphere ?

Explanation

### Step-by-Step Solution:

1. **Definition of Biosphere**: The biosphere is defined as the global sum of all ecosystems. It is the zone of life on Earth, a closed system, and largely self-regulating.

2. **Components of the Biosphere**: The biosphere consists of three main components: land (terrestrial ecosystems), water (aquatic ecosystems), and air (atmosphere). These elements are essential for sustaining life.

3. **Extent of the Biosphere**: The extent of the biosphere refers to the limits or boundaries within which life can exist.

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