Biosphere is

Options

A. a component in the ecosystem
B. composed of the plants present in the soil
C. life in the outer space
D. composed of all living organisms present on earth which interact with the physical environment

Explanation

**Step-by-Step Solution:**

1. **Understanding the Concept of Biosphere:**
- The biosphere is the global sum of all ecosystems. It represents the zone of life on Earth, where living organisms exist and interact with each other and their physical environment.

2. **Components of the Biosphere:**
- The biosphere is composed of both biotic (living organisms) and abiotic (non-living elements) components. The biotic components include all forms of life, such as plants, animals, and microorganisms. The abiotic components include elements like soil, water, air, and climate.

3. **Interaction Between Biotic and Abiotic Factors:**
- In the biosphere, living organisms (biotic factors) interact with their physical environment (abiotic factors). This interaction is crucial for the survival of organisms and the functioning of ecosystems.

4. **Defining the Biosphere:**
- The biosphere can be defined as the part of Earth where life exists, encompassing all living organisms and their relationships with the environment. It is also referred to as the ecosphere.

5. **Evaluating the Options:**
- When presented with options regarding the definition of the biosphere, the correct choice should encompass the idea that it includes all living organisms on Earth and their interactions with the abiotic components of the environment.

6. **Conclusion:**
- The correct answer to the question "Biosphere is" would be the option that states it is composed of all living organisms present on Earth that interact with their physical environment.

**Final Answer:**
The biosphere is composed of all living organisms present on Earth, which interact with their physical environment, including abiotic factors.

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