Q1: 1. What is the primary source of energy for all life on Earth?

• A) Wind
• B) Sun
• C) Moon
• D) Earth

Q2: 2. Which gas is essential for plant photosynthesis?

• A) Oxygen
• B) Nitrogen
• C) Carbon dioxide
• D) Helium

Q3: 3. What is the role of decomposers in an ecosystem?

• A) Produce oxygen
• B) Break down dead organisms
• C) Maintain temperature
• D) Provide shelter

Q4: 4. Where is the most biodiversity found on Earth?

• A) Deserts
• B) Oceans
• C) Grasslands
• D) Rainforests

Q5: 5. Which biome has the most extreme temperature variations?

• A) Tundra
• B) Tropical rainforest
• C) Desert
• D) Taiga

Q6: 6. What is the primary function of the ozone layer in Earth's atmosphere?

• A) Absorb carbon dioxide
• B) Block harmful UV radiation
• C) Regulate temperature
• D) Produce rain

Q7: 7. Which of the following is a renewable resource?

• A) Oil
• B) Coal
• C) Wind
• D) Natural gas

Q8: 8. What is the main cause of deforestation?

• A) Urbanization
• B) Climate change
• C) Logging
• D) Agricultural expansion

Q9: 9. Which ecosystem is characterized by high salt content?

• A) Coral reefs
• B) Mangroves
• C) Estuaries
• D) Salt marshes

Q10: 10. How does urbanization impact natural habitats?

• A) Increases biodiversity
• B) Decreases pollution
• C) Destroys habitats
• D) Promotes conservation

Q11: 11. What is the term for the variety of life forms in a particular habitat or ecosystem?

• A) Abundance
• B) Diversity
• C) Uniformity
• D) Homogeneity

Q12: 12. Which of the following is an example of a keystone species?

• A) Deer
• B) Eagle
• C) Beaver
• D) Wolf

Q13: 13. How does climate change affect marine life?

• A) Increases ocean acidity
• B) Reduces sea levels
• C) Promotes coral growth
• D) Enhances fish populations

Q14: 14. What is the main factor contributing to habitat loss?

• A) Conservation efforts
• B) Human activities
• C) Natural disasters
• D) Climate change

Q15: 15. Which of the following is an example of a natural ecosystem service?

• A) Waste disposal
• B) Water purification
• C) Air pollution
• D) Deforestation

Q16: 16. How do plants contribute to the oxygen cycle?

• A) Absorb oxygen
• B) Release carbon dioxide
• C) Release oxygen
• D) Absorb carbon dioxide

Q17: 17. What is the primary cause of soil erosion?

• A) Plant roots
• B) Wind
• C) Water runoff
• D) Human activities

Q18: 18. Which of the following is an example of a non-renewable resource?

• A) Solar energy
• B) Fossil fuels
• C) Wind power
• D) Geothermal energy

Q19: 19. How does overfishing impact marine ecosystems?

• A) Increases biodiversity
• B) Promotes coral growth
• C) Reduces fish populations
• D) Enhances water clarity

Q20: 20. What is the term for the process of one species benefiting at the expense of another?

• A) Mutualism
• B) Competition
• C) Parasitism
• D) Commensalism

Q21: 21. How do wetlands help prevent flooding?

• A) Absorb excess water
• B) Increase water levels
• C) Redirect water flow
• D) Cause erosion

Q22: 22. Which of the following is a natural disaster that can impact ecosystems?

• A) Forest fires
• B) Soil erosion
• C) Pollution
• D) Climate change

Q23: 23. What is the main driver of biodiversity loss?

• A) Natural selection
• B) Habitat destruction
• C) Genetic mutations
• D) Species migration

Q24: 24. How do coral reefs contribute to marine biodiversity?

• A) Reduce fish populations
• B) Provide shelter and food
• C) Increase ocean acidity
• D) Cause water pollution

Q25: 25. What is the impact of invasive species on native ecosystems?

• A) Promotes biodiversity
• B) Improves ecosystem balance
• C) Disrupts native species
• D) Enhances natural habitats