MPESB Group · Bite-size lessons
Environment
About 5 min · General Knowledge · English
Time worked out from the lesson's 294 words at 150 words a minute, plus a minute for each question.
The topic bridges pure science with current affairs, making it a high-value scoring area for candidates who understand core concepts.
Key ideas
- Ecosystem = Biotic (living organisms) + Abiotic (soil, water, air, sunlight) components interacting in a defined area. Energy flows one-way; nutrients cycle.
- Food Chain vs Food Web: Chain is linear (grass → deer → tiger); web is interconnected chains. Only 10% energy transfers between trophic levels (10% Rule).
- Ecological Pyramids: Pyramid of Energy is always upright. Pyramid of Biomass can be inverted in aquatic ecosystems. Pyramid of Numbers varies by ecosystem.
- Biodiversity Hotspots: India has 4 of world's 36 hotspots—Himalayas, Western Ghats, Indo-Burma, Sundaland. Hotspot = high endemism + habitat loss exceeding 70%.
- In-situ vs Ex-situ Conservation: In-situ = protecting species in natural habitat (national parks, sanctuaries). Ex-situ = outside natural habitat (zoos, seed banks, botanical gardens).
Quick reference
- 10% Rule: Only 10% energy passes to next trophic level
- MP has maximum tigers in India (as per recent census)
- 4 Indian Biodiversity Hotspots: Himalayas, Western Ghats, Indo-Burma, Sundaland
- AQI Severe Level: Above 400 (health emergency)
- CPCB: Central Pollution Control Board constituted in September 1974 under the Water (Prevention and Control of Pollution) Act, 1974
Check yourself: 3 questions
1. Which of the following gases is primarily responsible for the depletion of the ozone layer in the stratosphere?
2. The term 'biodiversity hotspot' refers to a region that must meet which two criteria?
3. Which international agreement, adopted in 2015, aims to limit global temperature rise to well below 2 degrees Celsius above pre-industrial levels?
This lesson is cut from the topic's note, not rewritten. Fact-checked on 17 Oct 2026: an AI-assisted check of this note against cited sources; the errors it found were corrected that day. Some errors may remain. The questions are from Shishya's validated question bank.
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