Looking for reliable SEBA Class 9 Science Chapter 14 (Natural Resources) extra questions and answers for the 2026–27 academic year? Access essential additional practice questions, biogeochemical cycle diagrams, environmental impact notes, short conceptual answers, and important exam questions to score top marks in your annual exams.
Extra question and answer
1. What is the atmosphere and why is it important for life?
Answer: The atmosphere is the blanket of air around the Earth.
It keeps the temperature steady, protects us from harmful rays, and provides oxygen for breathing.
2. How is the Earth’s atmosphere different from that of Venus and Mars?
Answer: Earth has oxygen and moderate CO₂, which support life.
Venus and Mars have 95–97% carbon dioxide, no oxygen, and extreme temperatures, so no life exists.
3. Why does air act like a blanket for Earth?
Answer: Air is a poor conductor of heat, so it prevents sudden temperature changes.
It keeps days cooler and nights warmer.
4. Why does the moon have extreme temperatures?
Answer: The Moon has no atmosphere.
So, heat is not controlled → very cold nights (–190°C) and very hot days (110°C).
5. Why does the composition of air remain balanced?
Answer: Plants use CO₂ for photosynthesis and release oxygen.
Animals use oxygen and release CO₂. This cycle keeps air composition stable.
6. What is the role of water vapour in the atmosphere?
Answer: It helps in cloud formation and controls humidity.
It also absorbs heat and influences weather.
7. How do marine animals help maintain CO₂ balance?
Answer: They use dissolved carbonates to make shells.
This removes CO₂ from water, keeping the balance stable.
8. What is air pollution?
Answer: Addition of harmful gases and particles (SO₂, NOₓ, smoke) makes air impure.
It causes diseases, smog, and environmental damage.
9. What is smog and how is it formed?
Answer: Smog = smoke + fog.
It forms in winter due to pollutants in cold air and reduces visibility.
10. List any three effects of air pollution.
Answer:
• Breathing problems like asthma
• Acid rain
• Damage to plants and buildings
SEBA Class 9 Science Chapter 14 Extra Questions
11. What causes the movement of air (winds)?
Answer: Uneven heating of land and water creates pressure differences.
Air moves from high pressure to low pressure → winds.
12. How does uneven heating generate local winds?
Answer: Land heats and cools faster than water.
This creates sea breeze (day) and land breeze (night).
13. What is a sea breeze?
Answer: During daytime, land heats faster.
Warm air rises → cool air from sea moves to land.
14. What is a land breeze?
Answer: At night, land cools faster.
Warm air over sea rises → cool air from land moves to sea.
15. Why do winds change direction in different places?
Answer: Because of Earth’s rotation and obstacles like mountains.
These factors bend or block wind flow.
16. How do mountains affect wind patterns?
Answer: They block the wind, forcing it to rise or move around.
This affects rainfall and temperature in nearby areas.
17. Why does air rise when heated?
Answer: Warm air becomes lighter and expands.
So it rises upwards forming convection currents.
18. What are convection currents?
Answer: Upward movement of warm air and downward movement of cool air form circular currents.
19. Why is weather prediction possible?
Answer: Weather satellites and instruments measure temperature, pressure, humidity and wind.
These data help predict weather changes.
20. How does the atmosphere help in climate control?
Answer: It absorbs and reflects heat, maintains stable temperature, and prevents extreme conditions.
Class 9 Science Chapter 14 Important Questions SEBA 2026-27
21. How are clouds formed?
Answer: Warm air rises and cools.
Water vapour condenses on dust particles forming tiny droplets → clouds.
22. What is evaporation?
Answer: Heating of water turns it into water vapour, which rises into the atmosphere.
23. What is condensation?
Answer: Cooling of water vapour into tiny droplets forms clouds.
24. How does rainfall occur?
Answer: Cloud droplets join to become heavy.
When they cannot stay suspended, they fall as rain.
25. Why are rainfall patterns different in different areas?
Answer: Because of wind directions, mountains, and monsoon patterns.
26. What is the water cycle?
Answer: Continuous process of evaporation, condensation, and rainfall.
It maintains water supply on Earth.
27. What is infiltration?
Answer: Rainwater that seeps into the soil and becomes groundwater.
28. How is snow formed?
Answer: If upper atmosphere is very cold, water droplets freeze and fall as snow.
29. How do monsoon winds bring rain to India?
Answer: South-west monsoon brings moisture-rich winds from the sea.
When they hit mountains, they release rain.
30. What is humidity?
Answer: Amount of water vapour present in the air.
High humidity makes weather feel hotter.
Natural Resources Class 9 SEBA Extra Question Answer
31. Why is fresh water important?
Answer: Chemical reactions in our body need water.
It helps transport substances and remove wastes.
32. Why can’t humans drink salty water?
Answer: High salt content harms cells and affects kidneys.
Fresh water is necessary for life processes.
33. Why is fresh water limited on Earth?
Answer: Most water is salty.
Only a small part is in rivers, lakes and groundwater.
34. Name three causes of water pollution.
Answer:
• Industrial chemicals
• Fertilizers & pesticides
• Sewage and microbes
35. How does hot water from factories harm aquatic life?
Answer: Hot water reduces dissolved oxygen.
Fish and other organisms can’t survive.
36. Why does low dissolved oxygen kill fish?
Answer: Fish need oxygen dissolved in water to breathe.
Pollution or heat reduces oxygen levels.
37. What is an algal bloom?
Answer: Excess nutrients cause algae to grow fast.
They use up oxygen and kill aquatic life.
38. How does water pollution affect humans?
Answer: It spreads diseases like cholera, diarrhea and skin infections.
It also contaminates drinking water.
39. How does water scarcity affect biodiversity?
Answer: Areas with less rainfall have fewer plants and animals.
Very dry regions support very few species.
40. What is groundwater?
Answer: Water stored below the soil in spaces between rocks.
We obtain it through wells and pumps.
SEBA Class 9 Science Chapter 14 Practice Notes
41. What is soil and why is it important?
Answer: Soil is a mixture of rock particles, humus and microorganisms.
It supports plant life and provides habitat for organisms.
42. How does the Sun help in soil formation?
Answer: Heat causes rocks to expand and contract.
Over time, cracks form and rocks break down into soil.
43. How does water help in soil formation?
Answer: Water freezes in rock cracks and breaks rocks.
Flowing water rubs rocks and carries particles that become soil.
44. How does wind help in soil formation?
Answer: Strong winds rub against rocks and break them.
Wind also carries soil particles to new places.
45. How do living organisms help in soil formation?
Answer: Lichens produce chemicals that break rocks.
Roots grow into cracks and widen them.
46. What is humus?
Answer: Decayed remains of plants and animals.
It increases soil fertility.
47. What is soil erosion?
Answer: Removal of top fertile soil by wind or water.
48. Name three causes of soil erosion.
Answer:
• Deforestation
• Overgrazing
• Heavy rainfall and floods
49. How can soil erosion be prevented?
Answer:
• Planting trees
• Terrace farming
• Building embankments
50. What is soil pollution?
Answer: Addition of chemicals like fertilizers and pesticides that kill soil organisms and reduce fertility.
Class 9 Science Natural Resources Important Questions
51. What is the nitrogen cycle?
Answer: Conversion of atmospheric nitrogen into usable compounds by bacteria and lightning.
Plants use these to make proteins.
52. Why can’t plants use nitrogen directly from the air?
Answer: Nitrogen gas is very stable.
Plants need nitrates or nitrites formed by bacteria.
53. What is nitrogen fixation?
Answer: Process of converting nitrogen gas into usable compounds by bacteria or lightning.
54. What is the carbon cycle?
Answer: Movement of carbon between atmosphere, plants, animals and soil.
55. How do plants help maintain carbon balance?
Answer: They absorb CO₂ during photosynthesis and release oxygen.
56. How does respiration add carbon dioxide to air?
Answer: Plants and animals release CO₂ when they break down food for energy.
57. How does burning fossil fuels affect the carbon cycle?
Answer: It adds extra CO₂ which increases global warming.
58. What is the greenhouse effect?
Answer: Process by which greenhouse gases (CO₂, methane) trap heat and keep Earth warm.
59. What causes global warming?
Answer: Excess greenhouse gases trap too much heat, raising Earth’s temperature.
60. What is the oxygen cycle?
Answer: Plants release oxygen during photosynthesis.
Organisms use oxygen for respiration and produce CO₂.
61. How is oxygen used in nature?
Answer:
• Respiration
• Burning
• Formation of oxides
62. What is ozone and where is it found?
Answer: Ozone is a gas (O₃) found in the upper atmosphere.
It protects us from harmful UV rays.
63. What damages the ozone layer?
Answer: CFCs from refrigerators, sprays and industrial gases.
64. Why is the ozone layer important for life?
Answer: It absorbs harmful ultraviolet radiation which can cause skin cancer and blindness.
65. Why are natural cycles important for life?
Answer: They recycle nutrients like carbon, nitrogen and oxygen.
This maintains balance in nature and supports life.
🔬 Updated Extra Questions Guide Notice: This page features an extensive collection of SEBA Class 9 Science Chapter 14 (Natural Resources) Extra Questions and Detailed Answers updated for the 2026–27 academic session. All nitrogen cycle steps, soil formation processes, water conservation notes, and environmental pollution concepts strictly follow the latest revised Assam Board (SEBA) curriculum.
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