NBC 105 • Unit 111 min read★ High Exam Frequency
Ecosystem Structure, Food Chains, Food Webs & Pyramids
Unit 1: Environment, Ecosystems & Human Impact • Environment and Ecology
👨🏫 Professor's Mental Model: The Biosphere Operating System
Ecosystem Earth ka natural Operating System hai. Green plants (Producers) solar energy ko data me compile karte hain, Animals (Consumers) us data ko process karte hain, aur Bacteria/Fungi (Decomposers) garbage collection karke nutrients wapas soil me recycle kar dete hain!
Ecosystem Structure & Components
Abiotic: Solar radiation, temperature, water, minerals, soil nutrients.
Biotic:
1. Producers (Autotrophs): Green plants/algae doing photosynthesis.
2. Consumers (Heterotrophs): Primary (Herbivores), Secondary (Carnivores), Tertiary (Apex predators).
3. Decomposers (Saprotrophs): Bacteria and fungi breaking down detritus.
Food Chain vs Food Web
Food Chain: Single linear pathway of energy transfer (Grass -> Grasshopper -> Frog -> Snake -> Hawk).
Food Web: Complex interconnected web of multiple food chains providing resilience and stability.
Ecological Pyramids (Charles Elton)
1. Pyramid of Numbers: Can be upright or inverted (single tree with many parasites).
2. Pyramid of Biomass: Upright on land; inverted in aquatic lakes/oceans.
3. Pyramid of Energy: ALWAYS UPRIGHT (Governed by Lindeman's 10% Rule: only ~10% energy transfers to the next trophic level).
🎯 University Exam Scoring Blueprint
- State Lindeman's 10% Energy Transfer Law with a numerical example.
- Draw a Grazing Food Chain vs Detritus Food Chain.
- Explain EIA: Environmental Impact Assessment.
Top Viva Questions on Ecosystem Structure, Food Chains, Food Webs & Pyramids
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