Environment & Ecology MCQs for UPSC and State PSC Exams

India General Knowledge

MODULE 9: Environment, Ecology & Biodiversity MCQs

Topic: Environment & Ecology MCQs for UPSC and State PSC Exams

The questions are systematically divided into clearly defined sub-topics and arranged in a logical–chronological sequence, ensuring conceptual clarity, syllabus alignment, and high relevance for UPSC, State PSCs, SSC, Banking, Railways, Forest Services, Teaching Eligibility Tests, University & Entrance Examinations.

Sub-Topic 1: Fundamentals of Environment & Ecology

Q1. Ecology is best defined as the study of:

A. Geological processes of Earth
B. Human population dynamics
C. Interactions between organisms and their environment
D. Atmospheric phenomena only

Correct Answer: C

Explanation:
Ecology focuses on relationships among living organisms and between organisms and their physical environment, forming the scientific basis of environmental studies.

Q2. Which of the following is a biotic component of an ecosystem?

A. Soil
B. Water
C. Air
D. Plants

Correct Answer: D

Explanation:
Biotic components include living organisms such as plants, animals, and microorganisms.

Q3. The physical and chemical surroundings of an organism are called:

A. Habitat
B. Ecosystem
C. Environment
D. Niche

Correct Answer: C

Explanation:
Environment includes all external physical, chemical, and biological factors influencing an organism.

Sub-Topic 2: Ecosystem Structure & Function

Q4. An ecosystem consists of:

A. Only plants
B. Only animals
C. Only abiotic components
D. Biotic and abiotic components

Correct Answer: D

Explanation:
An ecosystem includes living organisms interacting with non-living components such as air, water, and soil.

Q5. Producers in an ecosystem are mainly:

A. Herbivores
B. Carnivores
C. Green plants
D. Decomposers

Correct Answer: C

Explanation:
Producers synthesize food through photosynthesis, forming the base of food chains.

Q6. Which organisms recycle nutrients back into the ecosystem?

A. Producers
B. Herbivores
C. Carnivores
D. Decomposers

Correct Answer: D

Explanation:
Decomposers like bacteria and fungi break down dead matter, releasing nutrients back into the soil.

Sub-Topic 3: Food Chain, Food Web & Energy Flow

Q7. A food chain shows:

A. Energy flow in one direction
B. Circular energy movement
C. Random feeding relationships
D. Only plant-animal relations

Correct Answer: A

Explanation:
Energy flows unidirectionally from producers to consumers and decomposers.

Q8. Food webs are more stable than food chains because:

A. They have fewer organisms
B. They show multiple feeding pathways
C. Energy flow is slower
D. Producers are absent

Correct Answer: B

Explanation:
Multiple feeding links make ecosystems more resilient to disturbances.

Q9. According to the 10% law, energy transferred between trophic levels is about:

A. 1%
B. 5%
C. 10%
D. 50%

Correct Answer: C

Explanation:
Only about 10% of energy passes to the next trophic level; the rest is lost as heat.

Sub-Topic 4: Biogeochemical Cycles

Q10. Which cycle is mainly associated with photosynthesis and respiration?

A. Nitrogen cycle
B. Carbon cycle
C. Phosphorus cycle
D. Sulphur cycle

Correct Answer: B

Explanation:
The carbon cycle involves exchange of carbon through photosynthesis, respiration, and decomposition.

Q11. Which nutrient cycle lacks a gaseous phase?

A. Carbon
B. Nitrogen
C. Phosphorus
D. Oxygen

Correct Answer: C

Explanation:
The phosphorus cycle mainly occurs in rocks, soil, and water, lacking a significant gaseous phase.

Q12. Nitrogen fixation converts atmospheric nitrogen into:

A. Carbon dioxide
B. Ammonia
C. Nitrates only
D. Nitrous oxide

Correct Answer: B

Explanation:
Nitrogen-fixing bacteria convert nitrogen into ammonia, making it usable by plants.

Sub-Topic 5: Biodiversity & Its Conservation

Q13. Biodiversity refers to diversity at which levels?

A. Species level only
B. Genetic level only
C. Ecosystem level only
D. Genetic, species, and ecosystem levels

Correct Answer: D

Explanation:
Biodiversity includes genetic, species, and ecosystem diversity.

Q14. India is considered a megadiverse country because:

A. It has large deserts
B. It supports high species richness
C. It has maximum forest area
D. It has longest rivers

Correct Answer: B

Explanation:
India hosts rich biodiversity with high endemism across varied ecosystems.

Q15. In-situ conservation means:

A. Conserving species outside their habitat
B. Conserving species in their natural habitat
C. Seed banking
D. Botanical gardens

Correct Answer: B

Explanation:
In-situ conservation protects species within their natural ecosystems.

Sub-Topic 6: Environmental Pollution

Q16. Which type of pollution results from excessive nutrient enrichment of water bodies?

A. Thermal pollution
B. Marine pollution
C. Eutrophication
D. Noise pollution

Correct Answer: C

Explanation:
Eutrophication leads to algal blooms and oxygen depletion, harming aquatic life.

Q17. Major sources of air pollution in Indian cities include:

A. Forest fires only
B. Vehicular emissions and industries
C. Agriculture only
D. Volcanic activity

Correct Answer: B

Explanation:
Urban air pollution is largely due to vehicles, industries, and construction activities.

Q18. Which pollutant is responsible for acid rain?

A. Carbon monoxide
B. Sulphur dioxide
C. Methane
D. Ozone

Correct Answer: B

Explanation:
Sulphur dioxide and nitrogen oxides form acid rain, damaging ecosystems.

Sub-Topic 7: Climate Change & Global Warming

Q19. Global warming refers to:

A. Natural climate variability
B. Cooling of Earth
C. Increase in Earth’s average temperature
D. Seasonal climate change

Correct Answer: C

Explanation:
Global warming is the long-term rise in Earth’s average temperature.

Q20. The major greenhouse gas responsible for global warming is:

A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Hydrogen

Correct Answer: C

Explanation:
Carbon dioxide contributes most due to large emissions and long atmospheric life.

Q21. Climate change impacts India mainly through:

A. Stable rainfall
B. Glacier expansion
C. Extreme weather events
D. Reduced temperature variability

Correct Answer: C

Explanation:
India faces heatwaves, floods, droughts, and cyclones due to climate change.

Sub-Topic 8: Sustainable Development

Q22. Sustainable development emphasizes:

A. Economic growth only
B. Environmental protection only
C. Balance between development and environment
D. Industrial expansion

Correct Answer: C

Explanation:
It balances economic, social, and environmental needs.

Q23. The concept of sustainable development was defined in the:

A. Stockholm Declaration
B. Brundtland Report
C. Rio Declaration
D. Kyoto Protocol

Correct Answer: B

Explanation:
The Brundtland Report (1987) provided the classic definition.

Q24. Which SDG is directly related to climate action?

A. SDG 11
B. SDG 12
C. SDG 13
D. SDG 15

Correct Answer: C

Explanation:
SDG 13 focuses on combating climate change and its impacts.

Sub-Topic 9: Environmental Governance in India

Q25. Environmental protection in India is a subject under:

A. State List
B. Union List
C. Concurrent List
D. Residual powers

Correct Answer: C

Explanation:
Environment falls under the Concurrent List, involving both Centre and States.

Q26. The precautionary principle means:

A. Act only after damage occurs
B. Avoid development
C. Prevent harm even without full scientific certainty
D. Promote industrial growth

Correct Answer: C

Explanation:
It advocates preventive action in environmental protection.

Q27. The polluter pays principle implies:

A. Government pays for pollution
B. Polluters bear cost of environmental damage
C. Public pays equally
D. Industries are exempt

Correct Answer: B

Explanation:
Polluters must compensate for environmental harm they cause.

Sub-Topic 10: Integrated Environment & Ecology Perspective

Q28. Ecological balance refers to:

A. Equal number of species
B. Stable interaction among ecosystem components
C. Absence of humans
D. Maximum productivity

Correct Answer: B

Explanation:
Ecological balance maintains stability and sustainability of ecosystems.

Q29. Loss of biodiversity mainly results in:

A. Increased ecosystem resilience
B. Reduced ecosystem stability
C. Improved food chains
D. Higher productivity

Correct Answer: B

Explanation:
Biodiversity loss weakens ecosystem functioning and resilience.

Q30. Environment and ecology are important for UPSC and PSC exams because:

A. They are static topics only
B. They link science with current affairs
C. They are optional topics
D. They are rarely asked

Correct Answer: B

Explanation:
Environment & Ecology integrate science, policy, and current affairs, making them highly relevant for competitive exams.

• Environment and ecology MCQs

• UPSC environment MCQs

• State PSC environment questions

• Ecology GK MCQs for exams

• Biodiversity and ecosystem MCQs

• Climate change environment MCQs

• Sustainable development MCQs

• Indian environment GK questions

⭐ Why Environment & Ecology MCQs Are Essential for UPSC and State PSC Exams

Environment and Ecology is a core, high-scoring, and recurring area in UPSC and State PSC examinations. Questions are frequently asked from ecosystems, biodiversity, pollution, climate change, and sustainable development, often linked with current affairs.

This MCQ set offers:

• Clear coverage of static environment and ecology fundamentals

• Concept-based explanations suited for Prelims-oriented preparation

• Balanced focus on ecology, environment, and sustainability

• Ideal revision resource for UPSC, State PSCs, SSC, Banking, and Railways

Regular practice of these MCQs builds conceptual clarity, factual accuracy, and exam confidence.

❓ FAQ Section

Q1. Are Environment and Ecology important for UPSC Prelims?

Yes. Environment & Ecology questions appear every year in UPSC Prelims and often determine the cutoff.

Q2. What level of environment questions are asked in State PSC exams?

State PSC exams generally ask basic to moderate-level questions, focusing on ecology, biodiversity, pollution, and climate change.

Q3. How should beginners prepare Environment & Ecology for exams?

Start with basic concepts, revise standard terms, and practice MCQs with explanations regularly.

Q4. Are these MCQs useful for SSC and Banking exams?

Yes. SSC, Banking, and Railways exams frequently include environment and ecology questions in General Awareness sections.

Q5. Is current affairs knowledge required for environment questions?

Yes. Environment questions often link static concepts with current environmental issues and policies.

🎯 Targeted Competitive & Academic Examinations

These Environment & Ecology MCQs are designed for:

• UPSC Civil Services Examination (Prelims & Mains)

• State Public Service Commissions (APSC, BPSC, UPPSC, RPSC, MPPSC, etc.)

• SSC Exams (CGL, CHSL, MTS, GD)

• Banking Exams (IBPS, SBI, RBI, NABARD)

• Railway Exams (RRB NTPC, Group D)

• Forest Services & Environmental Exams

• Teaching Eligibility Tests (CTET & State TETs)

• University, College & Entrance Examinations

• School-level Competitive & Board Examinations