Among the biotic components of the ecosystem, the producer system is

The correct answer is D) Green Plants. Producers, or autotrophs, make their own food from inorganic substances. Green plants do this through photosynthesis, capturing solar energy and converting CO2 and water into carbohydrates. That is why they form the base of every food chain and the first trophic level.

• A) Cow: A primary consumer (herbivore). It depends on plants for energy and does not make its own food.
• B) Peacock: A consumer, feeding on insects, grains and small reptiles. It sits at a higher trophic level.
• C) Tiger: A top carnivore and tertiary consumer. It gets energy only by eating other animals.

The core concept is the trophic structure of an ecosystem and unidirectional energy flow, where only about 10 per cent of energy passes from one level to the next (Lindeman's law). This links directly to Mains questions on food security, forest-based carbon sequestration and the ecological cost of habitat loss.

Trap: Candidates sometimes read 'producer' as 'something that produces goods for humans' or pick the most familiar animal. Remember the ecological meaning: only autotrophs are producers.