In-text Questions — Trophic Levels and Decomposers — Our Environment

1. 13 marksNCERT Cl-10 Science, In-text Q after §13.1.1

   What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

   Hint. Each step in a food chain is one trophic level — start from the producer.

   Step 1 — Define a trophic level. Each step or level of a food chain, at which organisms feed on the level before it, forms a trophic level.

   Step 2 — Give an example food chain. Grass → Grasshopper → Frog → Snake.

   Step 3 — Name each trophic level. Grass is the producer (first trophic level), the grasshopper is the primary consumer/herbivore (second trophic level), the frog is the secondary consumer (third trophic level), and the snake is the tertiary consumer (fourth trophic level) — since each organism occupies the level right after whatever it eats.

   ✦ Answer: A trophic level is each feeding step of a food chain. Example: Grass (T1, producer) → Grasshopper (T2, primary consumer) → Frog (T3, secondary consumer) → Snake (T4, tertiary consumer).

   Where students slip. Listing organisms without an eating relationship between consecutive ones — a food chain (and its trophic levels) only makes sense if each organism actually feeds on the one before it.

2. 23 marksNCERT Cl-10 Science, In-text Q after §13.1.1

   What is the role of decomposers in the ecosystem?

   Hint. Think about what would happen to dead matter if nothing ever broke it down.

   Step 1 — Identify decomposers. Bacteria and fungi make up the decomposers.

   Step 2 — State what they do. They break down the complex organic substances present in the dead remains and waste products of organisms into simple inorganic substances.

   Step 3 — State why this matters. These simple inorganic substances go back into the soil and are used again by plants, since this replenishes the soil's nutrients and completes the cycling of matter through the ecosystem.

   ✦ Answer: Decomposers break down dead organisms and waste into simple inorganic substances, returning nutrients to the soil for reuse by producers — without them, nutrients would stay locked up in dead matter instead of cycling back through the ecosystem.

   Where students slip. Saying decomposers 'just clean up' dead matter — their real ecological role is returning nutrients to the soil, which is what keeps the whole nutrient cycle going, not just removal of waste.

Solutions written by the tuition.in editorial team and checked against the NCERT Class 10 Science textbook, Reprint 2026-27 (jesc113.pdf) — three in-text question sets (7 questions total) plus one end-of-chapter Exercise (9 questions, not the 8/13 an older manifest claimed). The chapter's own core content (ecosystems, food chains/webs, trophic levels, the 10% energy rule, biological magnification, ozone depletion, biodegradable/non-biodegradable waste) is intact. A fabricated fifth trophic level and an unverified 'Lindeman (1942)' name-drop were removed from the chapter page; content on the Chipko Movement, forest/wildlife conservation and India's environmental laws — which belongs to 'Sustainable Management of Natural Resources', the old Chapter 16 dropped entirely from the current 13-chapter book — was moved to the appendix.. Questions are referenced from the NCERT textbook for identification.