Question 1(a) [3 marks]

Write short note: Ecological pyramid.

Answer:

Table: Types of Ecological Pyramids

Type	Description	Example
Pyramid of Numbers	Shows number of organisms at each level	Trees → Insects → Birds
Pyramid of Biomass	Shows total mass of organisms	Large at producer level
Pyramid of Energy	Shows energy flow through levels	Always upright

Energy Transfer: Only 10% energy transfers to next level
Trophic Levels: Producers, primary consumers, secondary consumers
Always Upright: Energy pyramid never inverts

Mnemonic: "Number-Biomass-Energy flows UP"

Question 1(b) [4 marks]

Describe global ecological overshoot.

Answer:

Global ecological overshoot occurs when humanity's demand exceeds Earth's regenerative capacity.

Key Components:

Factor	Description
Earth Overshoot Day	Date when annual resource consumption exceeds regeneration
Ecological Footprint	Human demand on natural resources
Biocapacity	Earth's ability to regenerate resources

Current Status: Using 1.7 Earth's worth of resources annually
Consequences: Climate change, biodiversity loss, resource depletion
Solutions: Sustainable consumption, renewable energy adoption

Mnemonic: "Demand Exceeds Supply = Overshoot"

Question 1(c) [7 marks]

What are the Bio-geochemical cycle? Describe any two cycle of them.

Answer:

Bio-geochemical cycles are natural processes that recycle essential elements through biotic and abiotic components.

Carbon Cycle:

graph LR
    A[Atmosphere CO2] --> B[Plants Photosynthesis]
    B --> C[Animals Respiration]
    C --> A
    B --> D[Decomposition]
    D --> A
    A --> E[Ocean Absorption]
    E --> A

Nitrogen Cycle:

Stage	Process	Organisms
Nitrogen Fixation	N2 → NH3	Rhizobium bacteria
Nitrification	NH3 → NO3	Nitrosomonas, Nitrobacter
Denitrification	NO3 → N2	Denitrifying bacteria

Importance: Essential for protein synthesis and DNA formation
Human Impact: Fertilizers disrupt natural balance
Conservation: Reduce chemical fertilizer use

Mnemonic: "Bacteria Fix Nitrogen, Plants Use It"

Question 1(c) OR [7 marks]

Describe the forest ecosystem state and explain the effects of deforestation and suggest the methods to conserve forest ecosystem.

Answer:

Forest Ecosystem Components:

Component	Examples
Producers	Trees, shrubs, herbs
Primary Consumers	Deer, rabbits, insects
Secondary Consumers	Carnivores, birds
Decomposers	Bacteria, fungi

Effects of Deforestation:

graph TD
    A[Deforestation] --> B[Climate Change]
    A --> C[Biodiversity Loss]
    A --> D[Soil Erosion]
    A --> E[Water Cycle Disruption]

Conservation Methods:

Afforestation: Planting trees in new areas
Reforestation: Replanting in deforested areas
Protected Areas: National parks and sanctuaries
Sustainable Harvesting: Controlled logging practices

Mnemonic: "Plant, Protect, Practice Sustainability"

Question 2(a) [3 marks]

Write definition on pollution and pollutant.

Answer:

Definitions:

Term	Definition
Pollution	Addition of harmful substances to environment
Pollutant	Substance causing environmental contamination

Sources: Industrial, domestic, agricultural activities
Types: Air, water, soil, noise pollution
Effects: Health problems, ecosystem damage

Mnemonic: "Pollutants cause Pollution"

Question 2(b) [4 marks]

Explain short note on gravity settling chamber equipment to control air pollution.

Answer:

Gravity Settling Chamber:

+------------------+
|  Dirty Air  -->  |
|                  |
|   Particles      |
|      ↓           |
|  Collection      |
|    Chamber       |
|                  |
|  Clean Air  -->  |
+------------------+

Working Principle:

Parameter	Description
Mechanism	Gravitational settling of particles
Efficiency	50-70% for particles >50 μm
Velocity	Low gas velocity allows settling

Applications: Cement, mining, metallurgy industries
Advantages: Simple design, low maintenance cost
Limitations: Ineffective for fine particles

Mnemonic: "Gravity Settles Heavy Particles"

Question 2(c) [7 marks]

Describe solid waste management.

Answer:

Solid Waste Management Hierarchy:

graph LR
    A[Reduce] --> B[Reuse]
    B --> C[Recycle]
    C --> D[Recovery]
    D --> E[Disposal]

Management Methods:

Method	Description	Advantages
Landfill	Controlled burial	Simple, cost-effective
Incineration	High-temperature burning	Volume reduction
Composting	Biological decomposition	Nutrient-rich fertilizer
Recycling	Material recovery	Resource conservation

Components:

Collection: Door-to-door pickup systems
Transportation: Efficient vehicle routing
Treatment: Sorting, processing, disposal
Monitoring: Regular quality checks

Mnemonic: "Collect, Transport, Treat, Monitor"

Question 2(a) OR [3 marks]

Write effect on noise pollution.

Answer:

Effects of Noise Pollution:

Type	Effects
Health Effects	Hearing loss, stress, hypertension
Psychological	Irritation, sleep disorders, anxiety
Environmental	Wildlife disruption, ecosystem damage

Sources: Traffic, industries, construction, aircraft
Measurement: Decibel (dB) scale
Control: Sound barriers, noise regulations

Mnemonic: "Noise Harms Health and Habitat"

Question 2(b) OR [4 marks]

What is water pollution? Write list of main water pollutant?

Answer:

Water Pollution Definition: Contamination of water bodies by harmful substances making it unsuitable for use.

Major Water Pollutants:

Category	Examples
Chemical	Heavy metals, pesticides, fertilizers
Biological	Bacteria, viruses, parasites
Physical	Suspended solids, thermal pollution
Radioactive	Nuclear waste materials

Sources: Industrial discharge, domestic sewage, agricultural runoff
Effects: Disease transmission, ecosystem disruption
Control: Treatment plants, pollution prevention

Mnemonic: "Chemical, Biological, Physical, Radioactive"

Question 2(c) OR [7 marks]

What is E-waste? Write impact of E-waste on environment and human health. How to recycle E-waste?

Answer:

E-waste Definition: Electronic waste includes discarded electrical and electronic devices.

Environmental Impact:

graph TD
    A[E-waste] --> B[Soil Contamination]
    A --> C[Water Pollution]
    A --> D[Air Pollution]
    A --> E[Resource Depletion]

Health Impact:

Toxic Material	Health Effects
Lead	Nervous system damage
Mercury	Brain and kidney damage
Cadmium	Cancer, lung damage

E-waste Recycling Process:

Collection: Designated collection centers
Dismantling: Manual separation of components
Recovery: Extraction of valuable materials
Disposal: Safe handling of toxic substances

Mnemonic: "Collect, Dismantle, Recover, Dispose Safely"

Question 3(a) [3 marks]

What is BOD? Give a importance of BOD.

Answer:

BOD (Biochemical Oxygen Demand):

Parameter	Description
Definition	Oxygen required by microorganisms to decompose organic matter
Unit	mg/L or ppm
Test Period	5 days at 20°C

Importance:

Water Quality: Indicates organic pollution level
Treatment Efficiency: Monitors treatment plant performance
Environmental Health: Assesses aquatic ecosystem condition

Mnemonic: "Bacteria Oxygen Demand measures pollution"

Question 3(b) [4 marks]

Give a comparison of conventional and Non conventional energy sources.

Answer:

Energy Sources Comparison:

Parameter	Conventional	Non-Conventional
Examples	Coal, oil, natural gas	Solar, wind, biomass
Availability	Limited reserves	Unlimited/renewable
Environment	High pollution	Environment friendly
Cost	Initially cheap	High initial cost
Sustainability	Non-sustainable	Sustainable

Conventional: Depleting rapidly, cause greenhouse gases
Non-conventional: Clean, abundant, future energy solution
Transition: Global shift towards renewable energy

Mnemonic: "Conventional Pollutes, Renewable Sustains"

Question 3(c) [7 marks]

Give classification of wind turbines and explain horizontal axis wind turbine.

Answer:

Wind Turbine Classification:

graph TD
    A[Wind Turbines] --> B[Horizontal Axis - HAWT]
    A --> C[Vertical Axis - VAWT]
    B --> D[Upwind]
    B --> E[Downwind]
    C --> F[Darrieus]
    C --> G[Savonius]

Horizontal Axis Wind Turbine (HAWT):

Components:

Component	Function
Rotor Blades	Convert wind energy to rotational motion
Nacelle	Houses generator and gearbox
Tower	Supports turbine at optimal height
Foundation	Provides structural stability

Working Principle:

Wind Direction: Parallel to rotor axis
Blade Design: Aerodynamic lift principle
Power Generation: Variable speed operation
Efficiency: 35-45% energy conversion

Advantages:

High Efficiency: Better power coefficient
Mature Technology: Well-established design
Cost Effective: Lower maintenance costs

Mnemonic: "Horizontal High Efficiency"

Question 3(a) OR [3 marks]

Explain need for renewable energy.

Answer:

Need for Renewable Energy:

Reason	Description
Energy Security	Reduce import dependence
Environmental Protection	Zero carbon emissions
Economic Benefits	Job creation, cost reduction

Fossil Fuel Depletion: Limited reserves, increasing prices
Climate Change: Urgent need to reduce greenhouse gases
Sustainable Development: Meet present needs without compromising future

Mnemonic: "Security, Environment, Economy need Renewables"

Question 3(b) OR [4 marks]

Write a short note on Geo thermal energy.

Answer:

Geothermal Energy:

Heat energy stored beneath Earth's surface used for power generation.

Types:

Type	Temperature	Application
High Temperature	>150°C	Power generation
Medium Temperature	90-150°C	Direct heating
Low Temperature	<90°C	Heat pumps

Sources: Hot springs, geysers, underground reservoirs
Advantages: Continuous availability, low emissions
Applications: Electricity generation, space heating, industrial processes

Mnemonic: "Earth's Heat Powers Homes"

Question 3(c) OR [7 marks]

Explain the principal and working of solar photovoltaic cell. Give its uses.

Answer:

Solar Photovoltaic Cell Principle:

Converts sunlight directly into electricity using photovoltaic effect.

Working Process:

graph LR
    A[Sunlight] --> B[Silicon Cell]
    B --> C[Electron Movement]
    C --> D[Electric Current]
    D --> E[DC Power]
    E --> F[Inverter]
    F --> G[AC Power]

Cell Structure:

Layer	Material	Function
Top Layer	N-type silicon	Excess electrons
Bottom Layer	P-type silicon	Electron holes
Junction	P-N junction	Electric field creation

Working Steps:

Photon Absorption: Light energy absorbed by silicon
Electron Excitation: Electrons gain energy and move
Current Generation: Electron flow creates electricity
External Circuit: Current flows through load

Applications:

Residential: Rooftop solar systems
Commercial: Solar farms, street lighting
Industrial: Remote power supply, satellites
Transportation: Solar vehicles, charging stations

Advantages:

Clean Energy: No emissions during operation
Low Maintenance: Minimal moving parts
Modular: Scalable installation

Mnemonic: "Sun Strikes Silicon, Sparks Current"

Question 4(a) [3 marks]

Explain Green house effect.

Answer:

Greenhouse Effect:

Natural process where certain gases trap heat in Earth's atmosphere.

Mechanism:

Step	Process
Solar Radiation	Sun's energy reaches Earth
Surface Absorption	Earth absorbs and heats up
Re-radiation	Earth emits infrared radiation
Gas Trapping	Greenhouse gases trap heat

Natural Effect: Maintains Earth's temperature for life
Enhanced Effect: Human activities increase greenhouse gases
Result: Global warming and climate change

Mnemonic: "Gases Trap Heat, Earth Heats"

Question 4(b) [4 marks]

Write international protocol to prevent climate change management.

Answer:

International Climate Protocols:

Protocol	Year	Objective
Kyoto Protocol	1997	Reduce greenhouse gas emissions
Paris Agreement	2015	Limit global warming to 1.5°C
Montreal Protocol	1987	Protect ozone layer

Key Features:

Emission Targets: Binding commitments for developed countries
Clean Development: Technology transfer to developing nations
Carbon Trading: Market-based emission reduction mechanisms
Monitoring: Regular reporting and verification systems

Mnemonic: "Kyoto, Paris, Montreal Protect Climate"

Question 4(c) [7 marks]

Explain biogas plant with neat sketch.

Answer:

Biogas Plant:

    Gas Outlet
        ↑
+---[Gas Holder]---+
|                  |
|  Slurry Chamber  |
|                  |
+--------+---------+
         |
    Inlet Tank
         ↓
    Organic Waste

Components:

Component	Function
Inlet Tank	Receives organic waste
Digester	Anaerobic decomposition occurs
Gas Holder	Stores produced biogas
Outlet	Removes spent slurry

Working Process:

Loading: Organic waste mixed with water
Digestion: Bacteria decompose waste anaerobically
Gas Production: Methane and CO2 generated
Collection: Gas stored in holder for use

Raw Materials:

Animal Waste: Cow dung, poultry droppings
Plant Waste: Agricultural residues, kitchen waste
Water: Maintains proper consistency

Products:

Biogas: 50-70% methane for cooking/heating
Slurry: Excellent organic fertilizer

Advantages:

Renewable: Continuous gas production
Waste Management: Converts waste to energy
Rural Development: Suitable for villages

Mnemonic: "Waste In, Gas Out, Fertilizer Bonus"

Question 4(a) OR [3 marks]

Write short note on green house gases.

Answer:

Greenhouse Gases:

Gas	Source	Contribution
Carbon Dioxide	Fossil fuels, deforestation	76%
Methane	Agriculture, landfills	16%
Nitrous Oxide	Fertilizers, combustion	6%
Fluorinated Gases	Industrial processes	2%

Properties: Absorb and emit infrared radiation
Impact: Trap heat causing global warming
Control: Reduce emissions, use alternatives

Mnemonic: "CO2, CH4, N2O, F-gases Heat Earth"

Question 4(b) OR [4 marks]

Explain ozone layer depletion.

Answer:

Ozone Layer Depletion:

Reduction of ozone concentration in stratosphere due to human activities.

Causes:

Substance	Source	Effect
CFCs	Refrigerants, aerosols	Break down ozone molecules
Halons	Fire extinguishers	Catalytic ozone destruction
Methyl Bromide	Pesticides	Ozone layer thinning

Process:

UV Breakdown: UV radiation breaks CFC molecules
Chlorine Release: Free chlorine atoms released
Ozone Destruction: Chlorine destroys ozone molecules
Chain Reaction: One CFC molecule destroys many ozone molecules

Effects: Increased UV radiation, skin cancer, crop damage

Mnemonic: "CFCs Climb, Chlorine Chops Ozone"

Question 4(c) OR [7 marks]

Explain the term "climate changes and state its causes and effects"

Answer:

Climate Change Definition: Long-term shifts in global weather patterns and temperatures.

Causes:

graph TD
    A[Climate Change Causes] --> B[Natural]
    A --> C[Human Activities]
    B --> D[Solar Variations]
    B --> E[Volcanic Eruptions]
    C --> F[Greenhouse Gas Emissions]
    C --> G[Deforestation]
    C --> H[Industrial Activities]

Human Causes:

Activity	Contribution
Fossil Fuel Burning	65% of CO2 emissions
Deforestation	15% of emissions
Industrial Processes	20% of emissions

Effects:

Environmental Effects:

Temperature Rise: Global average temperature increase
Sea Level Rise: Thermal expansion and ice melting
Weather Extremes: More frequent droughts, floods

Biological Effects:

Species Migration: Animals moving to cooler regions
Ecosystem Disruption: Food chain alterations
Biodiversity Loss: Species extinction rates increase

Human Effects:

Agriculture: Crop yield changes, food security issues
Health: Heat stress, disease vector changes
Economy: Infrastructure damage, adaptation costs

Mitigation Strategies:

Renewable Energy: Transition from fossil fuels
Energy Efficiency: Reduce consumption
Carbon Sequestration: Forest conservation, tree planting
International Cooperation: Global agreements and policies

Mnemonic: "Human Actions Heat Earth, Everyone Affected"

Question 5(a) [3 marks]

Explain "Khet Talavadi".

Answer:

Khet Talavadi (Farm Pond):

Small water harvesting structure in agricultural fields for irrigation.

Features:

Parameter	Description
Size	20m x 20m x 3m depth
Capacity	1200 cubic meters
Cost	Subsidized by government

Purpose: Rainwater collection, irrigation during dry periods
Benefits: Increased crop yield, groundwater recharge
Construction: Lined with plastic sheets or cement

Mnemonic: "Farm Pond Stores Rain for Crops"

Question 5(b) [4 marks]

Give goal and advantage of green building.

Answer:

Green Building Goals:

Goal	Description
Energy Efficiency	Reduce energy consumption
Water Conservation	Minimize water usage
Material Efficiency	Use sustainable materials
Indoor Environment	Improve air quality

Advantages:

Environmental: Reduced carbon footprint, waste minimization
Economic: Lower operating costs, increased property value
Health: Better indoor air quality, natural lighting
Social: Enhanced occupant comfort, productivity

Green Building Features:

Solar Panels: Renewable energy generation
Rainwater Harvesting: Water conservation
Green Roofs: Insulation and air purification

Mnemonic: "Green Goals: Energy, Water, Materials, Environment"

Question 5(c) [7 marks]

Explain various methods of rain water harvesting.

Answer:

Rainwater Harvesting Methods:

Surface Methods:

graph TD
    A[Rainwater Harvesting] --> B[Surface Methods]
    A --> C[Groundwater Methods]
    B --> D[Ponds and Tanks]
    B --> E[Check Dams]
    C --> F[Percolation Pits]
    C --> G[Recharge Wells]

Detailed Methods:

Method	Description	Application
Rooftop Harvesting	Collect water from building roofs	Urban areas
Surface Runoff	Capture water from ground surface	Rural areas
Check Dams	Small barriers across streams	Hilly regions
Percolation Tanks	Allow water to seep underground	Groundwater recharge

System Components:

Catchment Area: Surface collecting rainwater
Conveyance System: Gutters, pipes for transport
Storage System: Tanks, ponds for holding water
Filter System: Remove debris and contaminants

Rooftop Harvesting Process:

Collection: Rain falls on roof surface
Conveyance: Water flows through gutters and downspouts
First Flush: Initial dirty water diverted
Storage: Clean water stored in tanks
Distribution: Water used for various purposes

Benefits:

Water Security: Reduce dependence on external supply
Flood Control: Reduce surface runoff and flooding
Groundwater Recharge: Replenish underground aquifers
Cost Savings: Reduce water bills

Design Considerations:

Rainfall Data: Annual precipitation patterns
Catchment Area: Available roof/ground area
Storage Capacity: Based on demand and supply
Water Quality: Treatment requirements

Mnemonic: "Catch, Convey, Store, Filter, Use"

Question 5(a) OR [3 marks]

What is Life cycle analysis (LCA)?

Answer:

Life Cycle Analysis (LCA):

Systematic evaluation of environmental impacts of a product throughout its entire life cycle.

LCA Stages:

Stage	Description
Raw Material	Resource extraction
Manufacturing	Production processes
Use Phase	Product utilization
End of Life	Disposal or recycling

Purpose: Identify environmental hotspots, compare alternatives
Applications: Product design, policy decisions, consumer choices

Mnemonic: "Life Cycle: Raw, Make, Use, Dispose"

Question 5(b) OR [4 marks]

Give main features of the biological diversity Act, 2002

Answer:

Biological Diversity Act, 2002:

Main Features:

Feature	Description
Three-tier Structure	National, State, Local Biodiversity Boards
Prior Approval	Required for bio-resource access
Benefit Sharing	Equitable sharing with local communities
Bio-piracy Prevention	Protect traditional knowledge

Key Provisions:

Access Regulation: Control over biological resources
Sustainable Use: Conservation through utilization
Community Rights: Recognize local community contributions
Penalties: Strict punishment for violations

Objectives: Conservation, sustainable use, equitable benefit sharing

Mnemonic: "Biodiversity Act: Access, Benefit, Conserve, Protect"

Question 5(c) OR [7 marks]

Explain 5R.

Answer:

5R Concept:

Waste management hierarchy for environmental sustainability.

The 5Rs:

graph TD
    A[5R Hierarchy] --> B[1. Refuse]
    A --> C[2. Reduce]
    A --> D[3. Reuse]
    A --> E[4. Repurpose]
    A --> F[5. Recycle]

Detailed Explanation:

R	Definition	Examples	Benefits
Refuse	Avoid unnecessary items	Plastic bags, disposables	Prevent waste generation
Reduce	Minimize consumption	Energy, water, materials	Lower resource demand
Reuse	Use items multiple times	Containers, clothing	Extend product life
Repurpose	Find new uses for items	Tire planters, bottle crafts	Creative waste diversion
Recycle	Process into new products	Paper, plastic, metals	Material recovery

Implementation Strategies:

Personal Level:

Refuse: Say no to single-use plastics
Reduce: Buy only necessary items
Reuse: Repurpose containers and materials
Repurpose: Creative DIY projects
Recycle: Proper sorting and disposal

Community Level:

Awareness Programs: Education about 5R principles
Infrastructure: Recycling facilities and collection systems
Policies: Regulations promoting waste reduction
Incentives: Rewards for sustainable practices

Industrial Level:

Design for Durability: Long-lasting products
Material Selection: Recyclable and biodegradable materials
Circular Economy: Closed-loop production systems
Extended Producer Responsibility: Manufacturer accountability

Environmental Benefits:

Resource Conservation: Reduced raw material extraction
Energy Savings: Lower production energy requirements
Pollution Reduction: Decreased waste generation
Climate Protection: Reduced greenhouse gas emissions

Economic Benefits:

Cost Savings: Lower disposal and material costs
Job Creation: Green jobs in recycling and reuse sectors
Innovation: Development of sustainable technologies
Market Opportunities: New business models

Social Benefits:

Community Engagement: Collective environmental action
Health Improvement: Cleaner environment
Education: Environmental awareness and responsibility
Cultural Change: Sustainable lifestyle adoption

Challenges:

Behavior Change: Overcoming consumption habits
Infrastructure: Adequate recycling facilities
Economic Barriers: Initial investment requirements
Policy Support: Government regulations and incentives

Success Stories:

Zero Waste Cities: San Francisco, Kamikatsu
Corporate Initiatives: Company 5R programs
School Programs: Student environmental education
Community Projects: Local waste reduction efforts

Mnemonic: "Really Reduce Reuse Repurpose Recycle"