Assertion : Recycling of materials is must for the maintenance of biosphere .
Reason : Because energy flows unidirctionally in a food chain.

Options

A. If both Assertion and Reason are true and Reason is correct explanation of Assertion.
B. If both Assertion and Reason is not correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false.

Answer

**Step-by-Step Solution:**

1. **Identify the Assertion and Reason**:
- Assertion: "Recycling of materials is a must for the maintenance of the biosphere."
- Reason: "Because energy flows unidirectionally in a food chain."

2. **Evaluate the Assertion**:
- The assertion states that recycling of materials is essential for maintaining the biosphere. This is true because recycling helps to sustain ecosystems by returning nutrients to the environment, which supports plant growth and overall ecosystem health.

3. **Evaluate the Reason**:
- The reason given is that energy flows unidirectionally in a food chain. This statement is also true. In a food chain, energy is transferred from one trophic level to another, but it is not recycled; instead, it is lost as heat at each level.

4. **Determine the Relationship**:
- While both the assertion and the reason are true, the reason does not explain the assertion. The assertion is about the necessity of recycling materials, while the reason discusses the flow of energy, which is a separate concept.

5. **Choose the Correct Option**:
- Based on the evaluation, the correct option is: "Both assertion and reason are true, and the reason is not a correct explanation of the assertion."

**Final Answer**: The correct option is that both the assertion and reason are true, but the reason is not a correct explanation of the assertion.

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