Question

Given below are two statements:
Statement I: In an ecosystem, there is unidirectional flow of energy of sun from producers to consumers.
Statement II: Ecosystems are exempted from the law of thermodynamics.

• A. Both Statement I and Statement II are incorrect.
• B. Statement I is correct but Statement II is incorrect.
• C. Statement I is incorrect but Statement II is correct.
• D. Both Statement I and Statement II are correct.

Hint:

Energy flows one way. Thermodynamics applies to everything!

Answer 1

The Correct Option is B

Statement I is correct: Energy flow in an ecosystem is unidirectional. It originates from the sun, is captured by producers (photosynthesis), and then flows through different trophic levels (consumers). Energy is lost as heat at each level, so it cannot cycle back to producers in the same way nutrients do.
Statement II is incorrect: Ecosystems are \textit{not} exempt from the laws of thermodynamics. The second law, in particular, is relevant: energy transformations are never 100\% efficient, and some energy is always lost as heat. This explains the unidirectional flow of energy in ecosystems.