SECTION-A
Answer any twenty questions (All 25 solved for full coverage): 1 x 20 = 20
1. Define ecosystem.
An ecosystem is a structural and functional unit of the biosphere consisting of a community of living organisms interacting with their physical environment
.2. Give two examples of lentic ecosystem.
Examples of lentic (standing water) ecosystems include Ponds and Lakes
.3. What is the main source of energy in an ecosystem?
The Sun is the primary source of energy for almost all ecosystems
.4. Who coined the term 'succession'?
The term 'succession' was coined by Adolphe Dureau de la Malle
.5. What is the role of decomposers in an ecosystem?
Decomposers break down dead organic matter into simpler inorganic substances, facilitating nutrient cycling within the ecosystem
.6. Name two non-renewable resources.
Coal and Petroleum are non-renewable resources
.7. What is soil erosion?
Soil erosion is the displacement of the upper layer of soil caused by the action of water, wind, or human activities
.8. Name two commercial uses of forest.
- Timber for construction and furniture.
- Raw materials for the paper and pulp industry.
- Habitat loss and fragmentation.
- Poaching and overexploitation.
- Grazing Food Chain: Starts from green plants (e.g., Grass -> Grasshopper -> Frog -> Snake).
- Detritus Food Chain: Starts from dead organic matter (e.g., Dead leaves -> Woodlouse -> Blackbird).
- Primary Succession: Occurs in essentially lifeless areas where there is no soil (e.g., bare rock, newly formed volcanic island).
- Secondary Succession: Occurs in areas where a community that previously existed has been removed by a disturbance but the soil remains (e.g., abandoned farmland, burned forest).
- In-situ Conservation: Conserving species in their natural habitats (e.g., National Parks, Wildlife Sanctuaries, Biosphere Reserves).
- Ex-situ Conservation: Conserving species outside their natural habitats (e.g., Botanical Gardens, Zoological Parks, Seed Banks).
- Pyramid of Number: Shows the number of individual organisms at each trophic level (e.g., Upright in grasslands).
- Pyramid of Biomass: Shows the total dry weight of living matter at each level (e.g., Upright in terrestrial, but can be inverted in aquatic ecosystems).
- Pyramid of Energy: Shows the rate of energy flow. This is always upright because energy is lost as heat at each transfer.
- Himalayas: Rich in endemic species like the Snow Leopard.
- Western Ghats: High levels of endemism in amphibians and plants.
- Indo-Burma Region: Includes parts of North-East India.
- Sundaland: Includes Nicobar Islands.
- Human Health: Increased risk of skin cancer, cataracts, and weakened immune systems.
- Environment: Reduced growth of phytoplankton in oceans, damaging aquatic food chains.
- Plants: Disruption of plant physiological and developmental processes.
- Started in the early 1970s in the Uttarakhand Himalayas.
- The term 'Chipko' means 'to hug'; villagers (led by women like Gaura Devi) hugged trees to prevent contractors from felling them.
- Prominent leaders included Sunderlal Bahuguna and Chandi Prasad Bhatt.
- It was a non-violent (Satyagraha) movement that successfully led to a ban on commercial felling in the region.
- Wildlife Protection Act: 1972.
- WWF: World Wide Fund for Nature.
- CITES: Convention on International Trade in Endangered Species.
- For 8-mark questions, always include diagrams (e.g., Nitrogen cycle, Ecological Pyramids) to secure full marks.
- Differentiate clearly between primary and secondary pollutants with examples.
- Mention local examples for biodiversity questions, such as National Parks in Assam.
- Confusing 'In-situ' (natural) with 'Ex-situ' (artificial) conservation.
- Forgetting that the Pyramid of Energy is always upright.
9. What are the major types of energy resources?
Energy resources are broadly categorized into Renewable and Non-renewable resources
.10. Mention one reason for land degradation.
Deforestation is a major cause of land degradation
.11. Define biodiversity.
Biodiversity is the variety and variability of life forms on Earth, including diversity at genetic, species, and ecosystem levels
.12. Name two Wildlife Sanctuaries of Assam.
Pobitora Wildlife Sanctuary and Laokhowa Wildlife Sanctuary
.13. Write the full form of WWF.
World Wide Fund for Nature
.14. Mention two major threats to biodiversity.
15. Name two endangered plant species of North-East India.
Pitcher plant (Nepenthes khasiana) and Red Vanda
.16. What do you mean by environmental pollution?
Environmental pollution is the unfavorable alteration of our surroundings through undesirable changes in physical, chemical, or biological characteristics of air, water, and land
.17. Name the unit of noise measurement.
Decibel (dB)
.18. Define primary pollutants.
Primary pollutants are substances emitted directly into the atmosphere from a source, such as carbon monoxide from vehicle exhaust
.19. Mention two sources of soil pollution.
Industrial waste and excessive use of chemical fertilizers/pesticides
.20. When was the Wildlife Protection Act enacted?
The Wildlife Protection Act was enacted in 1972
.21. What is environmental ethics?
Environmental ethics is a branch of philosophy that studies the moral relationship of human beings to, and also the value and moral status of, the environment and its non-human contents
.22. Define deep ecology.
Deep ecology is an environmental philosophy that promotes the inherent worth of all living beings regardless of their instrumental utility to human needs
.23. Name the plant which was saved by Bishnois of Rajasthan.
The Khejri tree (Prosopis cineraria)
.24. Mention two man-made causes of landslides.
Deforestation on slopes and unscientific road construction/mining
.25. Name the instrument that can measure the intensity of earthquake.
Seismograph (The intensity is measured on the Richter scale)
.SECTION-B
Answer any five questions: 2 x 5 = 10
26. What do you mean by food chain? Mention its types with examples.
A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another
.27. Differentiate between Primary and Secondary succession.
28. What are renewable resources? Give examples.
Renewable resources are those that can be replenished naturally over short periods of time
. Examples include Solar energy, Wind energy, and Hydropower.30. Differentiate between in-situ and ex-situ conservation of biodiversity with suitable examples.
31. Write the full form of CITES. Name two National Parks of Assam.
CITES: Convention on International Trade in Endangered Species of Wild Fauna and Flora
.National Parks in Assam: Kaziranga National Park and Manas National Park
.32. Define greenhouse effect. Name two greenhouse gases found in the earth's atmosphere.
The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere
. Key gases include Carbon dioxide (CO2) and Methane (CH4).SECTION-C
Answer any five questions: 8 x 5 = 40
36. What is ecological pyramid? Discuss the different types of ecological pyramids with suitable examples. [1+7=8]
An ecological pyramid is a graphical representation of the relationship between different organisms in an ecosystem at various trophic levels
.37. Define biogeochemical cycle. Illustrate the nitrogen cycle with a diagram. [2+6=8]
A biogeochemical cycle is the movement of chemical elements and compounds between living organisms and the physical environment (atmosphere, soil, water)
.Steps of Nitrogen Cycle: Nitrogen fixation (atmospheric N2 to ammonia), Nitrification (ammonia to nitrites/nitrates), Assimilation (plants taking up nitrogen), Ammonification (conversion of waste to ammonia), and Denitrification (nitrates back to N2 gas)
.40. What is biodiversity hotspot? Discuss the biodiversity hotspots found in India. [2+6=8]
A biodiversity hotspot is a biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction
.Hotspots in India:
42. What is ozone layer depletion? What are the impacts of ozone depletion on the environment and human health? [2+6=8]
Ozone layer depletion is the thinning of the ozone layer in the stratosphere caused by the release of chemical compounds like Chlorofluorocarbons (CFCs)
.Impacts:
45. What is the aim of the environmental movement? Write a note on the Chipko Movement. [2+6=8]
Environmental movements aim to protect natural resources and ensure sustainable living by advocating for policy changes and public awareness
.Chipko Movement: