Biology · Ecosystems · NEET
Grass is the producer (first trophic level). The Goat eats grass, so it is a primary consumer or herbivore (second trophic level). Man eats the Goat, so Man is a secondary consumer (third trophic level). Energy flows in one direction: Grass to Goat to Man. This is a grazing food chain because it starts with a living green plant.
A food chain starts with a producer because only green plants (autotrophs) can trap sunlight and make their own food by photosynthesis. Animals cannot make food; they depend on plants directly or indirectly. So plants are the entry point of energy into every food chain. For NEET, remember: no producer means no food chain.
A trophic level is the position or step an organism occupies in a food chain based on what it eats. Producers are the first trophic level, herbivores (primary consumers) are the second, primary carnivores (secondary consumers) are the third, and so on. In Grass to Goat to Man, there are three trophic levels.
In Grass to Goat to Man, Man eats the Goat (a herbivore), so Man is a secondary consumer here. But if Man eats grass or fruit directly, Man becomes a primary consumer. The label depends on the exact food chain, not on the animal itself. NEET often tests this shift.
A food chain is a single straight path (Grass to Goat to Man). A food web is many food chains linked together, showing that one organism can be eaten by several others and can eat several foods. In nature, food webs are real; food chains are the simple building blocks. This distinction is a common NEET point.
Yes. Primary consumers feed directly on producers (plants), so they are always herbivores, such as insects, birds, mammals, and molluscs in water. Carnivores that eat herbivores are secondary consumers. NEET 2026 directly asked this: primary consumers are herbivores.
Which of the following are primary consumers in a food chain?
Match the trophic levels (grassland ecosystem) in Column I with the correct species in Column II: (a) First trophic level (b) Second trophic level (c) Third trophic level (d) Fourth trophic level; Species: (i) Crow (ii) Vulture (iii) Rabbit (iv) Grass
Try the real previous-year questions from this chapter — each with the answer and a full solution.
A food chain is a path that shows who eats whom, and how energy moves from one living thing to the next. It always begins with a producer (a green plant) and moves up to consumers. Example: Grass to Goat to Man.
Producers (plants that make food), consumers (animals that eat plants or other animals), and decomposers (bacteria and fungi that break down dead matter). In Grass to Goat to Man, Grass is the producer and Goat and Man are consumers.
It is a grazing food chain because it starts with a living green plant (grass). A detritus food chain instead starts with dead organic matter (detritus), not living plants.
Energy flows in one direction only, from the Sun to producers to consumers, and is lost as heat at each step. It never returns to the previous level, so the flow is unidirectional. NEET 2025 tested this directly.
Most food chains have three to four trophic levels. The number is limited because a lot of energy is lost as heat at each step (about 90% is lost), so little energy is left to support many levels.
