Chapter 12 of 22
Chapter 12: What if it Finishes...?
Fossil Fuels, Petroleum Refining, Vehicle Pollution & Renewable Energy | CBSE Session 2026–27
Core Pedagogical Competencies & Concepts
- Petroleum (crude oil) is a smelly, thick, dark liquid formed over millions of years from dead marine organisms buried under intense heat and pressure.
- Crude oil is refined into petrol, diesel, kerosene, LPG (cooking gas), CNG, bitumen (asphalt for roads), and wax.
- Fossil fuels are non-renewable; once depleted, they cannot be created quickly.
- Vehicular smoke releases dangerous pollutants like carbon monoxide and soot particles, causing asthma and lung diseases.
- Alternative renewable energy: solar energy, wind power, and battery-electric vehicles.
All Textbook Exercises & In-Text Tasks (22 Questions)
100% Complete Ingestion
Q1
Textbook Exercise
How was petroleum formed beneath the Earth? Why is it classified as a non-renewable natural resource?
[3 Marks]
✅ Step-by-Step Solution & Working
Petroleum was formed millions of years ago when tiny dead sea creatures and plants settled on the ocean floor and were buried under layers of sand and clay. Due to high pressure, extreme temperature, and absence of air over millions of years, the organic matter slowly transformed into crude oil.
It is non-renewable because human consumption is depleting existing reserves in decades, while nature requires millions of years to generate more.
It is non-renewable because human consumption is depleting existing reserves in decades, while nature requires millions of years to generate more.
CBSE Step-by-Step Marking Scheme
Biological formation over millions of years under heat/pressure
1.5 Marks
Non-renewable nature due to rapid depletion vs slow geological formation
1.5 Marks
Q2
Textbook Exercise
List four simple habits we can adopt to save petrol and diesel in everyday life.
[3 Marks]
✅ Step-by-Step Solution & Working
Four fuel-saving habits:
- Switch off the vehicle engine at traffic red lights and railway crossings.
- Use public transport (metro, buses, shared vans) instead of driving private cars.
- Walk or ride a bicycle for short-distance local errands.
- Carpool with friends or colleagues and maintain correct tire pressure in vehicles.
CBSE Step-by-Step Marking Scheme
Engine switch-off at signals & public transit use
1.5 Marks
Bicycles/walking & carpooling practices
1.5 Marks
Q3
Textbook Exercise
What products are obtained when crude petroleum is refined in an oil refinery? List six products and their uses.
[4 Marks]
✅ Step-by-Step Solution & Working
Crude petroleum is refined into multiple essential commercial fuels and materials:
- Petrol: Fuel for motorcycles, scooters, and cars.
- Diesel: Fuel for heavy transport (trucks, buses, tractors, trains, generators).
- LPG (Liquefied Petroleum Gas): Clean cooking gas for home kitchens.
- CNG (Compressed Natural Gas): Eco-friendly fuel for city buses and auto-rickshaws.
- Kerosene: Fuel for lamps, pressure stoves, and aviation turbojet fuel.
- Bitumen / Coal Tar & Paraffin Wax: Surfacing roads, making candles, vaseline, and ointments.
CBSE Step-by-Step Marking Scheme
Naming 6 petroleum byproducts accurately
2 Marks
Stating practical applications for each product
2 Marks
Q4
Textbook Exercise
What environmental and health problems are caused by smoke and exhaust gases emitted by millions of vehicles in cities?
[3 Marks]
✅ Step-by-Step Solution & Working
Vehicle exhaust contains toxic pollutants:
- Harmful Gases: Carbon monoxide, nitrogen oxides, sulphur dioxide, and fine particulate matter (PM2.5).
- Health Impacts: Inhaling vehicle exhaust causes burning eyes, coughing, bronchitis, asthma attacks, lung infections, and heart stress.
- Environmental Damage: Exhaust emissions form toxic smog in winter, acid rain, and contribute heavily to global warming and climate change.
CBSE Step-by-Step Marking Scheme
Listing pollutants (carbon monoxide, PM2.5, nitrogen oxides)
1.5 Marks
Health consequences (asthma, lung disease) and urban smog
1.5 Marks
Q5
Textbook Exercise
Why are solar energy and electric vehicles considered the future of clean transportation? Mention two advantages.
[3 Marks]
✅ Step-by-Step Solution & Working
Solar energy and electric vehicles (EVs) are clean, sustainable alternatives to fossil fuels:
- Zero Tailpipe Emissions: Electric vehicles do not burn petrol or diesel and emit zero exhaust smoke, drastically improving city air quality.
- Renewable & Inexhaustible: Sunlight is free, limitless, and available in abundance in India; unlike petroleum reserves, solar energy will never run out.
CBSE Step-by-Step Marking Scheme
Zero emission air quality benefit
1.5 Marks
Infinite renewable nature of solar power
1.5 Marks
Q6
Think and Discuss • Environmental Science & Ecology • What if it Finishes...?
[Textbook Activity & Question 1] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q7
Find Out and Write • Observational Field Study • What if it Finishes...?
[Textbook Activity & Question 2] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q8
Scientific Investigation • Ecosystem Relationships • What if it Finishes...?
[Textbook Activity & Question 3] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q9
Traditional Wisdom & Community Stewardship • Conservation • What if it Finishes...?
[Textbook Activity & Question 4] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q10
Survey & Data Collection • Experiential Inquiry • What if it Finishes...?
[Textbook Activity & Question 5] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q11
Health, Diet & Human Biology • Nutritional Science • What if it Finishes...?
[Textbook Activity & Question 6] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q12
Disaster Preparedness & Climate Resilience • Geography • What if it Finishes...?
[Textbook Activity & Question 7] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q13
Biodiversity & Habitat Adaptations • Wildlife Protection • What if it Finishes...?
[Textbook Activity & Question 8] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q14
Think and Discuss • Environmental Science & Ecology • What if it Finishes...?
[Textbook Activity & Question 9] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q15
Find Out and Write • Observational Field Study • What if it Finishes...?
[Textbook Activity & Question 10] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q16
Scientific Investigation • Ecosystem Relationships • What if it Finishes...?
[Textbook Activity & Question 11] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q17
Traditional Wisdom & Community Stewardship • Conservation • What if it Finishes...?
[Textbook Activity & Question 12] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q18
Survey & Data Collection • Experiential Inquiry • What if it Finishes...?
[Textbook Activity & Question 13] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q19
Health, Diet & Human Biology • Nutritional Science • What if it Finishes...?
[Textbook Activity & Question 14] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q20
Disaster Preparedness & Climate Resilience • Geography • What if it Finishes...?
[Textbook Activity & Question 15] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q21
Biodiversity & Habitat Adaptations • Wildlife Protection • What if it Finishes...?
[Textbook Activity & Question 16] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
Q22
Think and Discuss • Environmental Science & Ecology • What if it Finishes...?
[Textbook Activity & Question 17] In 'What if it Finishes...?', describe how students can conduct an empirical investigation or discussion on this topic and explain the scientific principles involved.
[3 Marks]
✅ Step-by-Step Solution & Working
Scientific Model Answer & Environmental Analysis:
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
1. Field Inquiry / Observation: In What if it Finishes...?, students examine real-world ecological relationships, habitat dependencies, and sustainable environmental practices.
2. Scientific Core Principles: Applying primary scientific methods—such as formulating a hypothesis, measuring field parameters, and recording observations in a nature journal—reveals direct linkages between human communities and natural cycles.
3. Stewardship Conclusion: Understanding these concepts cultivates empathy for living organisms and empowers students to implement eco-friendly conservation measures in daily life.
CBSE Step-by-Step Marking Scheme
Observation methodology & identification of ecological concepts
1.0 M
Scientific explanation of natural cause-and-effect processes
1.0 M
Actionable conservation recommendations stated clearly
1.0 M
🌟 NEP 2020 Competency-Based Case Study
Petroleum Depletion & Sustainable Urban Mobility
A traffic jam at an intersection in New Delhi caused thick black smoke, blaring horns, and stinging eyes among school children waiting in a bus. A digital board nearby showed that petroleum reserves will last for barely 40-50 more years at current consumption rates.
Analytical Task: Explain why petroleum is called a non-renewable fossil fuel and propose three sustainable alternatives for urban public transportation.
Evaluation & Model Answer:
Why Petroleum is Non-Renewable:
Petroleum was formed millions of years ago from the decomposed remains of prehistoric marine plants and animals buried under extreme heat and pressure beneath tectonic layers. Once extracted, nature cannot replenish these reserves in a human timeframe.
Three Sustainable Urban Transportation Solutions:
1. Electric Mass Transit: Metro rail networks and electric buses (e-buses) powered by solar or wind grid electricity produce zero street-level exhaust.
2. Compressed Natural Gas (CNG) & Green Hydrogen: Burns far cleaner than petrol and diesel, releasing minimal particulate soot.
3. Pedestrian & Bicycle Green Corridors: Developing safe cycling tracks and carpooling incentives to drastically reduce private automobile use.
Rubric: 2 Marks for fossil fuel genesis explanation + 3 Marks for three distinct sustainable transit alternatives = 5 Marks