Questions on Soil and Water (Ecology)
Multiple-Choice Questions: Soil and Water (Ecology)
1. What is the primary ecological role of soil?
A) To provide shade
B) To regulate temperature
C) To support plant growth and anchor organisms
D) To produce oxygen
E) To filter sunlight
2. Which of the following components is not typically found in soil?
A) Minerals
B) Organic matter
C) Water
D) Plastic
E) Air
3. Water is essential for living organisms primarily because:
A) It prevents gravity
B) It transports nutrients and aids cellular processes
C) It generates wind
D) It is solid at room temperature
E) It provides sunlight
4. What process causes the loss of fertile topsoil due to wind or water?
A) Photosynthesis
B) Sedimentation
C) Erosion
D) Infiltration
E) Condensation
5. The water table is defined as:
A) The water used in agriculture
B) Water flowing on the soil surface
C) The upper level of groundwater in an aquifer
D) A riverbank ecosystem
E) A water-based food web
6. What is infiltration in the context of soil and water?
A) Plants absorbing light
B) Air entering soil
C) Water seeping into the ground
D) Soil moving upward
E) Evaporation of water from soil
7. Which soil type has the best water retention?
A) Sand
B) Clay
C) Gravel
D) Silt
E) Loam
8. What is loam soil known for?
A) Having no organic matter
B) Being too dry for crops
C) A balanced mix of sand, silt, and clay
D) Poor aeration
E) Causing floods
9. Which of the following pollutes soil and water ecosystems?
A) Crop rotation
B) Composting
C) Deforestation and pesticide use
D) Natural precipitation
E) Mulching
10. The process of water cycling through the environment is known as:
A) Biodegradation
B) Hydrologic cycle
C) Nitrogen cycle
D) Fossilization
E) Mineralization
11. Soil is important for carbon storage because:
A) It releases methane
B) It traps plastics
C) Organic matter stores carbon in the ground
D) It reflects sunlight
E) It absorbs nitrogen
12. Which layer of soil is most fertile and rich in organic material?
A) Bedrock
B) Subsoil
C) Topsoil
D) Parent material
E) Claypan
13. Water that moves across the land surface instead of soaking into the ground is called:
A) Groundwater
B) Transpiration
C) Runoff
D) Percolation
E) Condensation
14. Aquifers are:
A) Underground layers that store groundwater
B) Layers of clay that block water
C) River deltas
D) Surface water sources
E) Volcanic rocks
15. Which of the following helps conserve soil?
A) Overgrazing
B) Terracing
C) Monoculture farming
D) Deforestation
E) Paving land
16. What is a major threat to freshwater availability?
A) Cloud formation
B) Glacier formation
C) Water pollution and overuse
D) Rainfall
E) Soil salinity
17. A healthy soil ecosystem contains:
A) Only sand and clay
B) Fungi, bacteria, and invertebrates
C) Mostly plastic particles
D) Heavy metals
E) No water or organic matter
18. Which process involves plants releasing water vapor into the atmosphere?
A) Condensation
B) Evaporation
C) Transpiration
D) Infiltration
E) Percolation
19. A wetland is important ecologically because it:
A) Reduces humidity
B) Blocks animal movement
C) Filters water and supports biodiversity
D) Increases desertification
E) Causes erosion
20. Which agricultural practice can reduce water and soil pollution?
A) Using synthetic fertilizers only
B) Over-irrigation
C) Integrated pest management (IPM)
D) Slash-and-burn farming
E) Ignoring crop rotation
Answer Key with Explanations
1. C – Soil supports plant growth and provides a stable environment for many organisms.
2. D – Plastic is synthetic and not a natural component of soil.
3. B – Water is vital for nutrient transport and cellular functions.
4. C – Erosion removes topsoil, which is rich in nutrients.
5. C – The water table is the top boundary of groundwater saturation.
6. C – Infiltration refers to water entering the soil.
7. B – Clay holds water well due to its small particle size.
8. C – Loam is ideal for plants due to its balanced texture.
9. C – Deforestation and chemicals harm ecosystems.
10. B – The hydrologic cycle describes water movement through Earth's systems.
11. C – Soil organic matter stores significant amounts of carbon.
12. C – Topsoil is the most nutrient-rich layer.
13. C – Runoff is surface water flow that may cause erosion or carry pollutants.
14. A – Aquifers are underground stores of water.
15. B – Terracing prevents erosion on slopes.
16. C – Pollution and overuse are major threats to freshwater sources.
17. B – A diverse soil biome maintains ecosystem health.
18. C – Transpiration is water release through plant leaves.
19. C – Wetlands act as natural filters and biodiversity hotspots.
20. C – IPM uses natural methods to reduce reliance on harmful chemical
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