FYUG EVEN SEMESTER EXAM, 2024
ECOLOGY AND ENVIRONMENTAL SCIENCE (2nd Semester)
Course No.: EESVAC-151T (Environmental Studies)
Time: 3 Hours | Full Marks: 70 | Pass Marks: 28
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
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2. Give two examples of lentic ecosystem.
Examples of lentic (standing water) ecosystems include Ponds and Lakes
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3. What is the main source of energy in an ecosystem?
The Sun is the primary source of energy for almost all ecosystems
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4. Who coined the term 'succession'?
The term 'succession' was coined by Adolphe Dureau de la Malle
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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
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6. Name two non-renewable resources.
Coal and Petroleum are non-renewable resources
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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
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8. Name two commercial uses of forest.
- Timber for construction and furniture
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- Raw materials for the paper and pulp industry
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9. What are the major types of energy resources?
Energy resources are broadly categorized into Renewable and Non-renewable resources
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10. Mention one reason for land degradation.
Deforestation is a major cause of land degradation
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11. Define biodiversity.
Biodiversity is the variety and variability of life forms on Earth, including diversity at genetic, species, and ecosystem levels
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12. Name two Wildlife Sanctuaries of Assam.
Pobitora Wildlife Sanctuary and Laokhowa Wildlife Sanctuary
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13. Write the full form of WWF.
World Wide Fund for Nature
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14. Mention two major threats to biodiversity.
- Habitat loss and fragmentation
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- Poaching and overexploitation
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15. Name two endangered plant species of North-East India.
Pitcher plant (Nepenthes khasiana) and Red Vanda
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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
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17. Name the unit of noise measurement.
Decibel (dB)
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18. Define primary pollutants.
Primary pollutants are substances emitted directly into the atmosphere from a source, such as carbon monoxide from vehicle exhaust
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19. Mention two sources of soil pollution.
Industrial waste and excessive use of chemical fertilizers/pesticides
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20. When was the Wildlife Protection Act enacted?
The Wildlife Protection Act was enacted in 1972
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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
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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
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23. Name the plant which was saved by Bishnois of Rajasthan.
The Khejri tree (Prosopis cineraria)
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24. Mention two man-made causes of landslides.
Deforestation on slopes and unscientific road construction/mining
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25. Name the instrument that can measure the intensity of earthquake.
Seismograph (The intensity is measured on the Richter scale)
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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
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- Grazing Food Chain: Starts from green plants (e.g., Grass -> Grasshopper -> Frog -> Snake)
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- Detritus Food Chain: Starts from dead organic matter (e.g., Dead leaves -> Woodlouse -> Blackbird)
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27. Differentiate between Primary and Secondary succession.
- Primary Succession: Occurs in essentially lifeless areas where there is no soil (e.g., bare rock, newly formed volcanic island)
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- 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)
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28. What are renewable resources? Give examples.
Renewable resources are those that can be replenished naturally over short periods of time
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Examples include Solar energy, Wind energy, and Hydropower.
30. Differentiate between in-situ and ex-situ conservation of biodiversity with suitable examples.
- In-situ Conservation: Conserving species in their natural habitats (e.g., National Parks, Wildlife Sanctuaries, Biosphere Reserves)
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- Ex-situ Conservation: Conserving species outside their natural habitats (e.g., Botanical Gardens, Zoological Parks, Seed Banks)
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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
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National Parks in Assam: Kaziranga National Park and Manas National Park
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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
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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
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- Pyramid of Number: Shows the number of individual organisms at each trophic level (e.g., Upright in grasslands)
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- 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)
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- Pyramid of Energy: Shows the rate of energy flow. This is always upright because energy is lost as heat at each transfer.
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)
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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)
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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
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Hotspots in India:
- Himalayas: Rich in endemic species like the Snow Leopard
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- Western Ghats: High levels of endemism in amphibians and plants
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- Indo-Burma Region: Includes parts of North-East India
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- Sundaland: Includes Nicobar Islands
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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)
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Impacts:
- Human Health: Increased risk of skin cancer, cataracts, and weakened immune systems
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- Environment: Reduced growth of phytoplankton in oceans, damaging aquatic food chains
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- Plants: Disruption of plant physiological and developmental processes
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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
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Chipko Movement:
- Started in the early 1970s in the Uttarakhand Himalayas
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- The term 'Chipko' means 'to hug'; villagers (led by women like Gaura Devi) hugged trees to prevent contractors from felling them
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- Prominent leaders included Sunderlal Bahuguna and Chandi Prasad Bhatt
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- It was a non-violent (Satyagraha) movement that successfully led to a ban on commercial felling in the region
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