FYUG Even Semester Examination, 2025
Ecology and Environmental Science
(Environmental Studies)

Paper Metadata & Examination Details

Instructions: Figures in the margin indicate full marks for the questions. Complete solutions for all alternative choices are provided below to ensure full syllabus coverage.

UNIT-I

Question 1: Answer any four of the following questions (1 Mark each)

(a) Who coined the term 'succession'?

The term 'succession' (specifically ecological succession) was first coined by the French naturalist Adolphe Dureau de la Malle in 1825. Later, the concept was thoroughly developed by Henry Chandler Cowles and Frederic Clements.

(b) Define ecosystem.

An ecosystem is a structural and functional unit of the biosphere consisting of a community of living organisms (biotic component) interacting with their non-living physical environment (abiotic component) through energy flows and nutrient cycles.

(c) Give two examples of lentic ecosystem.

Lentic ecosystems refer to standing or still water habitats. Two examples are:

• Ponds
• Lakes

(d) Name the main source of energy in an ecosystem.

The main source of energy in almost all ecosystems is Solar Energy (the Sun).

(e) Give an example of gaseous type of biogeochemical cycle.

An example of a gaseous biogeochemical cycle is the Carbon Cycle (or the Nitrogen Cycle), where the primary reservoir is the atmosphere.

Question 2: Answer any one question of the following (2 Marks)

(a) What is food web? Give example.

A food web is a network of interconnected, interlocking food chains operating within an ecosystem. Unlike a simple linear food chain, a food web illustrates that consumers can feed on multiple trophic levels, providing stability to the ecosystem.

Example: In a terrestrial ecosystem, grass is eaten by grasshoppers, rabbits, or mice. The mouse may be eaten by an owl, a hawk, or a snake. This web of pathways forms a food web.

(b) Differentiate between primary and secondary successions.

Question 3: Answer any one question of the following (8 Marks)

Note: As per standard structural distribution, this block addresses detailed landscape and energy ecology concepts. All sub-options are completed.

(a) What is ecological pyramid? Discuss its types with examples.

An ecological pyramid is a graphical representation designed to show the biomass, biological productivity, or total energy content at each trophic level in a given ecosystem. The concept was introduced by Charles Elton.

Types of Ecological Pyramids:

1. Pyramid of Numbers: It shows the total number of individual organisms at each trophic level.
   • Upright Example: Grassland ecosystem (many grass individuals support fewer herbivores, which support even fewer carnivores).
   • Inverted Example: Parasitic food chain (a single tree supports many herbivorous birds, which support thousands of parasites).
2. Pyramid of Biomass: It represents the total dry weight of living organic matter at each trophic level.
   • Upright Example: Forest ecosystem (the massive dry weight of trees diminishes progressively up to primary and secondary consumers).
   • Inverted Example: Aquatic ecosystem (the small standing crop of phytoplankton supports a much larger biomass of zooplankton and fish due to rapid turnover rates).
3. Pyramid of Energy: It illustrates the total amount of energy available at each trophic level per unit area and time.
   • Characteristics: Always Upright, conforming to Lindeman's 10% law, which states that only about 10% of the energy is transferred to the next higher level; the rest is lost as metabolic heat.

(b) Write short notes on the following (4 + 4 = 8 Marks):

(i) Forest ecosystem

A forest ecosystem is a complex terrestrial community dominated by trees, shrubs, woody vegetation, and a wide array of fauna. Abiotic variables like precipitation, temperature, and soil topography dictate whether the forest is tropical, temperate, or boreal. Biotically, trees act as primary producers, herbivores (like deer and insects) function as primary consumers, and carnivores (like tigers or wolves) represent higher trophic levels. Decomposers recycle essential organic content back into the rich forest forest floor soil.

(ii) Pond ecosystem

A pond ecosystem is a classic example of a small, self-sustaining lentic freshwater habitat. It displays clear vertical stratification based on light penetration. The producers include macroscopic aquatic plants (macrophytes) along the shallow edges and microscopic floating phytoplankton in the open water. Primary consumers comprise zooplankton and benthic organisms, which are consumed by small fish (secondary consumers) and larger predatory fish or birds (tertiary consumers). Bacteria and fungi on the pond floor break down dead organic matter.

UNIT-II

Question 4: Answer any four of the following questions (1 Mark each)

(Questions captured focus on core definitions of land degradation and resource categorization)

(a) What is land degradation?

Land degradation is the decline in the productive capacity, soil fertility, and economic value of land caused by human-induced processes or natural phenomena like soil erosion, salinization, and deforestation.

(b) What causes soil erosion?

Soil erosion is primarily caused by natural agents like heavy rainfall running off surfaces, strong winds blowing over bare lands, and accelerated human activities such as deforestation, overgrazing, and unscientific agricultural practices.

(c) Give one example of a non-renewable resource.

Coal (or Petroleum) is a classic non-renewable resource that takes millions of years to form and cannot be replenished once consumed.

(d) Name two commercial uses of forest.

• Provision of timber for building materials, construction, and furniture manufacturing.
• Supply of wood pulp for paper and cellulose-based industries.

(e) Name two types of energy resources.

• Renewable Energy Resources (e.g., Solar, Wind)
• Non-renewable Energy Resources (e.g., Coal, Natural Gas)

Question 5: Answer any one question of the following (2 Marks)

(a) Differentiate between renewable and non-renewable resources with example.

Renewable resources are infinite assets that can replenish themselves naturally over short periods of time. Example: Solar energy, wind energy.
Non-renewable resources exist in fixed, finite quantities and are depleted through use because their natural geological generation cycles take millions of years. Example: Fossil fuels, uranium minerals.

(b) What are the causes of deforestation?

Deforestation is driven by several human-induced factors:

• Expansion of agricultural land for commercial farming and livestock ranching.
• Infrastructure developments such as highways, dams, and rapid urban sprawl.

Question 6: Answer any one question of the following (8 Marks)

(a) Give a detailed account on the use of surface and groundwater.

Water resources are fundamentally divided into surface water (rivers, lakes, reservoirs) and groundwater (aquifers tapped via wells). Both are vital assets across global sectors.

1. Sectors of Utilization:

• Agricultural Sector: The largest global consumer of water. Surface channels divert river networks, while tube wells pump deep groundwater to irrigate crops.
Industrial Sector: Used heavily for manufacturing, chemical processing, cleaning, and cooling thermal power plants.
• Domestic and Municipal Use: Purified surface water supplies urban centers for drinking, cooking, and sanitation. Areas lacking surface networks rely entirely on groundwater.

2. Issues and Over-exploitation Impacts:

• Aquifer Depletion: Pumping groundwater faster than natural rainwater recharge lowers water tables, forcing deeper drilling.
• Land Subsidence: Excessive extraction collapses empty underground pore spaces, causing the ground above to sink.
• Saltwater Intrusion: Over-extracting coastal aquifers pulls dense marine saltwater into clean freshwater zones, permanently spoiling the water source.

(b) Give a note on alternative sources of energy resources.

To combat the depletion of fossil fuels and reduce greenhouse gas emissions, transitioning to alternative, clean energy resources is paramount.

Key Alternative Sources:

• Solar Energy: Utilizing photovoltaic (PV) cells to directly convert sunlight into electricity or using solar thermal collectors for heating. It is abundant and clean.
• Wind Energy: Kinetic energy from wind drives massive wind turbines connected to electrical generators. It requires a minimal physical footprint once built.
• Hydroelectric Power: Harvesting the gravitational potential energy of falling or flowing water through dams to spin turbines. It offers a reliable baseline grid power.
• Geothermal Energy: Tapping into high-temperature heat reservoirs beneath the Earth's crust to generate steam and electricity. It operates continuously regardless of weather conditions.
• Biomass Energy: Deriving fuel from organic materials like agricultural residues, wood wastes, and specialized energy crops to create biofuels.

UNIT-III

Question 7: Answer any four questions of the following (1 Mark each)

(a) Define biodiversity.

Biodiversity refers to the variety and variability of all living organisms across different organizational levels, categorized into genetic diversity, species diversity, and ecosystem diversity.

(b) Name one Wildlife Sanctuary of Assam.

The Pobitora Wildlife Sanctuary (famous for the Indian one-horned rhinoceros) or the Garampani Wildlife Sanctuary.

(c) Write the full form of WWF.

The full form of WWF is the World Wide Fund for Nature (originally World Wildlife Fund).

(d) Name two endemic animal species of North-East India.

• Hoolock Gibbon (India's only ape species)
• Pygmy Hog

(e) What is the full form of IUCN?

The full form of IUCN is the International Union for Conservation of Nature.

Question 8: Answer any one question of the following (2 Marks)

(a) Name two biodiversity hotspots found in the Indian subcontinent.

• The Eastern Himalayas
• The Western Ghats

(b) What are the main threats to biodiversity?

The primary threats are often grouped under the acronym HIPPCO:

• Habitat Loss and Fragmentation: Driven by expanding agriculture and urban sprawl.
• Poaching and Overexploitation: Illegal wildlife trade and over-hunting of vulnerable species.

Question 9: Answer any one question of the following (8 Marks)

(a) Give a detailed account on human-wildlife conflict in India.

Human-Wildlife Conflict (HWC) arises when the needs of wildlife overlap directly with human activities, creating negative impacts for both populations, infrastructure, and native animal habitats.

1. Main Causes of Conflict:

• Encroachment and Habitat Fragmentation: The construction of railways, linear highways, and expanding agricultural zones cuts through ancient animal corridors.
• Depletion of Natural Prey Base: Degradation of interior forests reduces herbivore populations, forcing large carnivores to seek domestic cattle along forest boundaries.
• Attractants on Farm Edges: Highly palatable crops like sugarcane and sweet grains draw wild elephant herds out of nearby protected parks.

2. Ecological and Economic Impacts:

• Loss of Human Lives and Property: Attacks by large carnivores or trampling by elephants cause human casualties, crop destruction, and severe financial losses for farmers.
• Retaliatory Killings: Local populations often poison or electrocute animals like leopards, tigers, and elephants to protect their community and livelihood.

3. Mitigation Strategies:

• Building physical barriers like solar-powered electric fencing and deep trenches around villages.
• Constructing eco-bridges and underpasses across highways running through wildlife pathways.
• Using early warning systems using community alerts, camera traps, and radio telemetry.

(b) Write short notes on the following (4 + 4 = 8 Marks):

(i) In Situ conservation

In Situ conservation means protecting plants and animals within their natural habitats. This approach preserves the entire ecosystem alongside the targeted species, allowing natural evolutionary processes to continue uninterrupted. Key legal designations under this method include National Parks, Wildlife Sanctuaries, and Biosphere Reserves. It is the most effective way to sustain large populations of diverse species concurrently.

(ii) Ex Situ conservation

Ex Situ conservation involves removing endangered species from their natural, threatened habitats to be managed in artificial, controlled environments. This method provides direct care for species facing imminent extinction in the wild. Key examples include Zoological Parks, Botanical Gardens, Seed Banks, and Cryopreservation labs. While highly controlled, it can be costly and limits natural evolutionary adaptation to changing wild environments.

UNIT-IV

Question 10: Answer any four of the following questions (1 Mark each)

(a) What is noise pollution?

Noise pollution is defined as the presence of unwanted, excessive, or disruptive sound in the environment that poses hazards to human health, physiological well-being, and wildlife behavioral patterns.

(b) Name one secondary air pollutant.

Ozone (O₃) (specifically ground-level ozone) or Peroxyacetyl Nitrate (PAN), which form through reactions between primary pollutants and atmospheric gases.

(c) What is climate change?

Climate change refers to long-term, significant shifts in global or regional climate patterns, particularly changes in temperature, precipitation, and wind patterns, driven largely by human greenhouse gas emissions.

(d) Give one source of soil pollution.

Excessive application of chemical fertilizers and synthetic pesticides in modern agricultural practices, or industrial toxic chemical leaks.

(e) Name two greenhouse gases present in the atmosphere.

• Carbon Dioxide (CO₂)
• Methane (CH₄)

Question 11: Answer any one question of the following (2 Marks)

(a) What is solid waste?

Solid waste refers to the broad spectrum of discarded, useless, or unwanted solid materials resulting from domestic, commercial, industrial, and agricultural operations. It includes municipal garbage, plastics, food scraps, and industrial slag.

(b) What are the effects of acid rain on environment?

• Soil Acidification: Leaches out vital soil nutrients like calcium and potassium while releasing toxic aluminum ions that damage plant roots.
• Aquatic Destruction: Lowers the pH of lakes and streams, causing reproductive failure in fish and killing sensitive aquatic organisms.

Question 12: Answer any one question of the following (8 Marks)

(a) What is ozone layer depletion? Discuss the impacts of ozone layer depletion on environment. (2 + 6 = 8 Marks)

Ozone layer depletion is the gradual thinning and destruction of the stratospheric ozone layer caused by the release of human-made chemical compounds containing chlorine and bromine, known as Ozone Depleting Substances (ODSs), such as Chlorofluorocarbons (CFCs) and Halons.

When these compounds reach the stratosphere, solar UV radiation breaks them down to release free chlorine atoms. A single chlorine atom can break apart thousands of ozone molecules via a catalytic chain reaction:

Cl + O₃ → ClO + O₂
ClO + O → Cl + O₂

Impacts on the Environment:

• Effects on Human Health: Increased exposure to harmful Ultraviolet-B (UV-B) rays leads to higher rates of skin cancers (melanoma), cataracts, and suppressed immune system function.
• Damage to Terrestrial Plant Life: Disrupts essential physiological and developmental processes in crops, altering plant growth dynamics and reducing agricultural yields.
• Disruption of Aquatic Ecosystems: High UV levels penetrate shallow waters, killing phytoplankton and zooplankton, which forms the foundation of marine food webs.
• Degradation of Materials: Synthetic polymers, plastics, and fabrics break down and age much faster under intense UV-B radiation, causing economic losses.

(b) Give a detailed account on the causes and effects of global warming.

Global warming is the long-term rise in the average temperature of Earth's climate system, driven primarily by human actions that amplify the greenhouse effect.

Primary Causes:

• Combustion of Fossil Fuels: Burning coal, oil, and natural gas for power generation and transportation releases vast amounts of Carbon Dioxide (CO₂).
• Deforestation: Cutting down forests reduces the planet's natural carbon sinks, leaving more CO₂ in the atmosphere.
• Agricultural Practices: Flooded rice paddies and enteric fermentation in livestock release significant quantities of Methane (CH₄).
• Industrial Emissions: Processes that release fluorinated gases like Hydrofluorocarbons (HFCs) with high global warming potentials.

Major Effects:

• Melting of Ice Caps and Glaciers: Triggers rapid retreat of alpine glaciers and polar ice sheets, causing sea levels to rise.
• Sea-Level Rise: Coastal cities face increased flooding risks, erosion, and permanent saltwater intrusion into freshwater supplies.
• Extreme Weather Events: Increases the frequency and severity of severe droughts, intense heatwaves, and powerful tropical cyclones.
• Ecological Shift and Extinctions: Many species cannot adapt or migrate fast enough to changing temperature zones, leading to biodiversity loss.

UNIT-V

Question 13: Answer any four of the following questions (1 Mark each)

(a) Define deep ecology.

Deep ecology is an environmental philosophy that recognizes the inherent worth of all living beings regardless of their instrumental utility to human needs, advocating for a radical restructuring of modern human societies.

(b) Who was the founder of the Bishnoi Movement?

The Bishnoi Movement was founded in the 15th century by Guru Jambheshwar (also known as Guru Jambhoji).

(c) Name the instrument used to measure the intensity of an earthquake.

An earthquake's intensity is assessed using the Modified Mercalli Scale (while its ground motion is recorded by a Seismograph).

(d) Mention one right of animal.

The right to live free from unnecessary cruelty, exploitation, and suffering caused by human activities.

(e) Write two causes of flood.

• Intense, prolonged cloudbursts and heavy monsoon rainfall.
• Siltation of river beds that reduces their water-carrying capacity.

Question 14: Answer any one question of the following (2 Marks)

(a) What is ecofeminism?

Ecofeminism is a philosophical and social movement that links feminism with environmentalism. It highlights parallels between society's domination and exploitation of nature and the oppression and marginalization of women.

(b) Write two principles of environmental ethics.

• Principle of Intergenerational Equity: The responsibility to preserve natural resources for future human generations.
• Principle of Biocentrism: Respecting all forms of life, acknowledging that humans are part of nature rather than its masters.

Question 15: Answer any one question of the following (8 Marks)

(a) Discuss the causes and effects of earthquake. Write the mitigation measures of earthquake.

An earthquake is a sudden shaking of the Earth's surface caused by a release of energy in the lithosphere that creates seismic waves.

1. Causes of Earthquakes:

• Tectonic Movements: The primary cause. Stress builds along tectonic plate boundaries and fault lines until it overcomes friction, snapping the rocks and releasing energy.
• Volcanic Activity: Magma movement beneath an active volcano can cause localized crustal shaking.
• Anthropogenic Triggers: Large reservoir-induced seismicity (from massive dams), deep-well fluid injection, and underground mining or nuclear testing.

2. Effects of Earthquakes:

• Structural Destruction: Collapses buildings, bridges, highways, and utility networks, leading to human casualties.
• Ground Displacements and Landslides: Triggers mass movements of rock and soil on steep hillsides.
• Liquefaction: Shaking causes loose, water-saturated soils to temporarily act like a liquid, undermining building foundations.
• Tsunamis: Undersea tectonic displacements can generate massive, destructive ocean waves.

3. Mitigation Measures:

• Enforcing strict seismic-resistant building codes and structural designs.
• Developing micro-zonation maps to avoid building critical infrastructure on high-risk fault zones.
• Conducting regular community drills and creating clear emergency response protocols.

(b) Give a detailed note on the Chipko Movement.

The Chipko Movement is a historic socio-ecological movement that began in the early 1970s in the Garhwal region of Uttarakhand (then part of Uttar Pradesh), India. The word 'Chipko' literally translates to "to hug" or "to cling to."

1. Origins and Key Drivers:

The movement was sparked by widespread anger over the government allocating large forest areas to commercial logging companies while denying local communities access to wood for basic tools. When loggers arrived, local villagers, led by pioneering figures like Sundarlal Bahuguna, Chandi Prasad Bhatt, and Gaura Devi, stepped forward to protect the trees.

2. Core Philosophy and Methods:

Villagers physically hugged the trees to form human shields, preventing loggers from cutting them down. The movement was strictly non-violent, drawing inspiration from Gandhian satyagraha principles. It highlighted that healthy forests are vital for preventing landslides and floods, shifting the focus from commercial profit to ecological balance.

3. Significance and Global Impact:

• It led to a 15-year ban on commercial green tree logging in the Himalayan forests, issued by Prime Minister Indira Gandhi.
• It marked a turning point by highlighting the central role women play in environmental conservation and resource management.
• It inspired numerous future environmental movements across India, such as the Appiko Movement in Karnataka.