Q. 2. Which of the following constitute a food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
A food chain is constituted of different trophic levels.
(b) Grass Goat
Human; constitute a food chain.
Here, the grass is a producer, the goat is the primary consumer and humans are the secondary consumer.