🌍 Environment & Ecology MCQ Questions
Set – 2 | Competitive Examinations
Best for exams where Environment & Ecology has high relevance
Q11. Which human activity contributes most to ecological imbalance?
- (A) Deforestation
- (B) Social forestry
- (C) Afforestation
- (D) Vanamahotsav celebrations
Show Answer ▼
Correct answer is Deforestation. Cutting forests disrupts ecological balance and biodiversity.
Q12. The main role of trees in the environment is to:
- (A) Absorb noise
- (B) Release oxygen
- (C) Add carbon dioxide
- (D) Pollute air
Show Answer ▼
Correct answer is Release oxygen. Trees absorb CO₂ and release oxygen, supporting life.
Q13. In a food chain, the highest trophic level is occupied by:
- (A) Herbivores
- (B) Carnivores
- (C) Omnivores
- (D) Decomposers
Show Answer ▼
Correct answer is Carnivores. They are top predators in most ecosystems.
Q14. The main component of Earth’s atmosphere is:
- (A) Oxygen
- (B) Nitrogen
- (C) Carbon dioxide
- (D) Hydrogen
Show Answer ▼
Correct answer is Nitrogen. Nitrogen makes up about 78% of the air we breathe.
Q15. Which gas is essential for plant photosynthesis?
- (A) Carbon dioxide
- (B) Oxygen
- (C) Nitrogen
- (D) Hydrogen
Show Answer ▼
Correct answer is Carbon dioxide. Plants use CO₂ to produce glucose during photosynthesis.
Q16. Optimum concentration of carbon dioxide in the atmosphere for natural balance is:
- (A) 0.02%
- (B) 0.04%
- (C) 0.05%
- (D) 0.03%
Show Answer ▼
Correct answer is 0.04%. This is considered the safe atmospheric CO₂ concentration.
Q17. Which gas decreases if all plants vanish from Earth?
- (A) Oxygen
- (B) Carbon dioxide
- (C) Nitrogen
- (D) Water vapour
Show Answer ▼
Correct answer is Oxygen. Without plants, oxygen production stops, affecting all aerobic life.
Q18. Which process does NOT release carbon dioxide into the atmosphere?
- (A) Photosynthesis
- (B) Respiration
- (C) Decay of organic matter
- (D) Volcanic action
Show Answer ▼
Correct answer is Photosynthesis. Plants consume CO₂ in this process instead of releasing it.
Q19. Which cycle is directly driven by solar radiation?
- (A) Water cycle
- (B) Carbon cycle
- (C) Nitrogen cycle
- (D) Phosphorus cycle
Show Answer ▼
Correct answer is Water cycle. Solar energy drives evaporation and precipitation.
Q20. Biodiversity conservation helps primarily in:
- (A) Increasing pollution
- (B) Maintaining ecological balance
- (C) Reducing sunlight
- (D) Reducing rainfall
Show Answer ▼
Correct answer is Maintaining ecological balance. Protecting biodiversity ensures ecosystem stability.
🌿 Click “Show Score” after answering all Environment MCQs (Set-2)!
🌱🌎
🌱 Great work! Ready for Environment MCQs Set-3?
Keep exploring environmental concepts! Every set strengthens your understanding of sustainability. 🌎🌱
🧬 More General Science Questions and Answer
Explore exam-style MCQs for Physics, Chemistry, Enviroment-Ecology and Biology from competitive exams worldwide.
