🪵 Organisms and Populations (Adaptations & Interactions)
| Category / Interaction | NCERT Examples | Key High-Yield Feature |
|---|---|---|
| Morphological Adaptation | Kangaroo rat (North American desert) | Internal fat oxidation provides water; concentrates urine. |
| Anatomical Adaptation | Opuntia (Cactus), Hydrophytes (Hydrilla) | Opuntia: Thick cuticle, sunken stomata, leaves modified to spines. |
| Behavioral Adaptation | Desert Lizard | Basks in sun when body temp drops; moves to shade when hot. |
| Physiological Adaptation | Altitude Sickness relief (Rohtang Pass) | Body increases RBC production and decreases Hb binding affinity. |
| Mutualism (+ / +) | • Lichens (Algae + Fungi) • Mycorrhizae (Glomus + Roots of higher plants) • Fig tree and Pollinator Wasp • Mediterranean Orchid (Ophrys) and Bee | Ophrys employs sexual deceit (pseudocopulation) with a male bee. |
| Competition (- / -) | • Abingdon tortoise and Goats (Galapagos) • Balanus and Chthamalus (Scotland) | Goats outcompeted tortoises for food. Competitive release seen in barnacles. |
| Predation (+ / -) | Prickly pear cactus and Cactus-feeding moth | Moth acted as a biological control agent in Australia. |
| Parasitism (+ / -) | • Ectoparasites: Lice on humans, Ticks on dogs, Cuscuta on hedge plants, Copepods on marine fish. • Endoparasites: Liver fluke, Plasmodium. • Brood Parasitism: Cuckoo (Koel) and Crow. | Cuscuta is a parasitic plant that has lost its chlorophyll and leaves. |
| Commensalism (+ / 0) | • Orchid growing on a Mango branch • Barnacles on the back of a Whale • Egret bird and Grazing Cattle • Sea Anemone and Clown Fish | The host (Mango, Whale, Cattle, Anemone) derives zero benefit or harm. |
| Amensalism (- / 0) | Penicillium (mould) and Staphylococcus (bacteria) | The mould secretes penicillin which kills bacteria without hurting itself. |
🌾 Ecosystem (Structure, Productivity & Pyramids)
| Category / Concept | NCERT Examples | Key Dynamic / Value / Exception |
|---|---|---|
| Primary Productivity Value | Global Annual Net Primary Productivity | 170 Billion Tons (dry weight) of organic matter. |
| Ocean Productivity Value | Oceans (despite covering 70% of Earth) | Only 55 Billion Tons (due to nitrogen limitation). |
| Detritivores | Earthworm | Breaks down detritus into smaller particles (Fragmentation). |
| Inverted Pyramid of Biomass | Sea / Marine Ecosystem | Phytoplankton (small biomass) supports a larger biomass of fish. |
| Inverted Pyramid of Numbers | A single large tree ecosystem | One tree supports many herbivorous birds and even more parasites. |
| Primary Succession Sites | Newly cooled lava, bare rock, newly created pond | Extremely slow process; takes thousands of years to build soil. |
| Secondary Succession Sites | Abandoned farm lands, burned or cut forests, flooded lands | Faster than primary succession because soil is already present. |
| Pioneer Species | • On Rocks: Lichens • In Water: Phytoplankton | Lichens secrete acids to dissolve rock and help form soil. |
| Climax Community | Mesophytic Forest | Stable, self-sustaining, and in near equilibrium with environment. |
🐼 Biodiversity and Conservation (Data & Case Studies)
| Category / Concept | NCERT Species Counts & Examples | High-Yield Concept / Value |
|---|---|---|
| Species Wealth Indication | • Ants: > 20,000 species • Beetles: > 300,000 species • Orchids: > 20,000 species • Fishes: > 28,000 species | Demonstrates the immense scale of global biodiversity. |
| Genetic Diversity | Rauwolfia vomitoria (Himalayan range) | Shows variation in the potency/concentration of active chemical reserpine. |
| Species Diversity | Western Ghats vs. Eastern Ghats | Western Ghats have greater amphibian species diversity. |
| Alexander von Humboldt | Species-Area Relationship | Equation: \(\log S = \log C + Z \log A\). Slope (Z) for frugivorous birds = 1.15. |
| Recent Extinctions | • Dodo (Mauritius) • Quagga (Africa) • Thylacine (Australia) • Steller's Sea Cow (Russia) • Three subspecies of Tiger (Bali, Javan, Caspian) | Direct consequence of human exploitation and habitat loss. |
| Habitat Loss & Fragmentation | Amazon Rain Forest ("Lungs of the planet") | Being cut and cleared for cultivating soya beans or beef cattle grasslands. |
| Alien Species Invasion | • Nile Perch introduced into Lake Victoria (East Africa) • Invasive weeds: Parthenium (carrot grass), Lantana, Eichhornia (Water hyacinth) • Clarias gariepinus (African catfish) | • Nile Perch caused extinction of > 200 species of cichlid fish. • African catfish poses a threat to indigenous catfishes. |
| Co-extinctions | Host fish and its unique parasites | When host fish goes extinct, its unique parasite assembly vanishes too. |
| In-Situ Conservation | Biosphere Reserves (14), National Parks (90), Wildlife Sanctuaries (448), Sacred Groves | Sacrod Groves: Khasi & Jaintia Hills (Meghalaya), Aravalli (Rajasthan). |
| Ex-Situ Conservation | Zoological Parks, Botanical Gardens, Wildlife Safari Parks | Cryopreservation (-196°C in liquid nitrogen), In-vitro fertilization, Seed Banks. |
| The Earth Summit (1992) | Held in Rio de Janeiro | Called upon nations for biodiversity conservation and sustainable utility. |
| The World Summit (2002) | Held in Johannesburg, South Africa | 190 countries pledged to significantly reduce biodiversity loss by 2010. |