Question

Energy flow in the ecosystem is:

• A. Unidirectional
• B. Bidirectional
• C. Multidirectional
• D. All of these

Hint:

Compare energy flow with the recycling of nutrients — energy is NOT recycled.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In an ecosystem, energy enters as sunlight, is fixed by producers, and passes to successive trophic levels (herbivores, carnivores) as organisms feed on one another.

Step 2: Why it cannot flow backwards:
At each transfer, most energy is lost as heat (respiration), obeying the second law of thermodynamics. Since lost heat cannot be reused by organisms, energy can never flow back from a higher trophic level to a lower one.

Final Answer:
Energy flow in an ecosystem is unidirectional.
Option (A) is correct.