Assertion: Pyramid of energy can never be inverted.
Reason: When energy flows from one trophic level to the next trophic level, some energy is always lost as heat at each step.

Options

A. If both assertion and reason are true and the reason is a correct explanation of the assertion.
B. If both assertion and reason are true but reason is not a correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Analyze the Assertion
The assertion states that "Pyramid of energy can never be inverted."

- **Explanation**: The pyramid of energy represents the flow of energy through different trophic levels in an ecosystem. At each trophic level, energy is transferred from one level to the next. However, only a small portion of this energy (approximately 10%) is passed on to the next level, while the majority (about 90%) is lost as heat. This consistent loss of energy ensures that the pyramid remains upright, as the energy available decreases at each successive trophic level.

**Conclusion**: The assertion is **true**.

### Step 2: Analyze the Reason
The reason states that "When energy flows from one trophic level to the next trophic level, some energy is always lost as heat at each step."

- **Explanation**: This statement accurately describes the process of energy transfer in an ecosystem. As energy moves from producers to consumers, a significant amount of energy is lost primarily as heat due to metabolic processes. This loss of energy is a fundamental principle of thermodynamics and is crucial in understanding why energy pyramids are structured the way they are.

**Conclusion**: The reason is also **true** and provides a correct explanation for the assertion.

### Final Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the answer to the question is that both statements are true, and the reason is the correct explanation for the assertion.