🧬
Ecology & Environment
Ecosystems, food chains, population ecology, biodiversity
Key Concepts
- Ecosystem: biotic + abiotic components interacting as a unit
- Food chain: producer → primary consumer → secondary consumer → tertiary consumer
- Only ~10% of energy is transferred between trophic levels (10% law)
- Biogeochemical cycles: nitrogen, carbon, phosphorus, water
- Biodiversity: genetic, species, ecosystem; hotspots are areas of high endemism
Important Formulae
| Net primary productivity | NPP = GPP − Respiration |
| Shannon diversity index | H = −Σ (pᵢ ln pᵢ) |
| Population growth (exponential) | dN/dt = rN |
| Population growth (logistic) | dN/dt = rN(K−N)/K |
Quick Tips
- Pyramid of numbers can be inverted (tree ecosystem); pyramid of energy is never inverted.
- Ecological succession: primary (bare rock) → pioneer species → climax community.
- Ex-situ conservation: zoos, seed banks, botanical gardens; in-situ: national parks, biosphere reserves.
Practice Questions
Practice 20 randomly selected NEET questions on Ecology & Environment. Answers are revealed after each question.
Start Practice →