Question

which of the following is true about trophic relationships between organisms in an ecosystem?
a autotrophs obtain energy from sun, primary consumers obtain energy from autotrophs and secondary consumers get energy from primary consumers.
b primary consumers obtain energy from sun, secondary consumers obtain energy from autotrophs. decomposers obtain energy from heat that is lost at all the levels of the trophic structure.
c autotrophs obtain energy from sun, decomposers obtain energy from autotrophs, and secondary consumers get energy from primary consumers.
d none of the above are true.

Explanation:

• Option A: Autotrophs (producers) use photosynthesis to get energy from the sun. Primary consumers (herbivores) eat autotrophs, and secondary consumers (carnivores/omnivores) eat primary consumers. This matches trophic energy flow.
• Option B: Primary consumers don’t get energy from the sun (autotrophs do), and secondary consumers don’t eat autotrophs (they eat primary consumers). Decomposers get energy from dead organic matter, not lost heat. So B is wrong.
• Option C: Decomposers get energy from dead organisms (not directly from autotrophs in the same way as consumers), so C is wrong.

Answer:

A. Autotrophs obtain energy from sun, primary consumers obtain energy from autotrophs and secondary consumers get energy from primary consumers.