Chapter 11: Nature's Treasures

Let us enhance our learning

1. Match the jumbled words with their corresponding natural resources shown in Fig. 11.9. Classify them as renewable or non-renewable.

• ocrk: Rock (Non-renewable)
• refost: Forest (Renewable)
• ndiw: Wind (Renewable)
• atwre: Water (Renewable)

2. State whether the following statements are True [T] or False [F]. If False, correct them.

• (i) Nature has all the resources to meet human needs. [T]
• (ii) Machines are a resource found in nature. [F] (Correction: Machines are human-made resources, not found in nature.)
• (iii) Natural gas is a non-renewable resource. [T]
• (iv) Air is a renewable resource. [T]

3. Fill in the blanks using the most appropriate option—

• (i) A fuel that is commonly used in two wheelers like scooters or bikes is: (b) Petrol
• (ii) An example of a renewable resource is: (b) Water

4. Classify the following as renewable or non-renewable resources—coal, natural gas, forests and minerals.

• Renewable: Forests
• Non-renewable: Coal, Natural gas, Minerals

5. Why do we say that petroleum is a non-renewable resource? Petroleum is considered a non-renewable resource because it takes millions of years to form from the remains of organisms buried deep inside the Earth. Once exhausted, it cannot be replenished within a reasonable period of time.

6. It is difficult to regrow forests. Justify this statement. Regrowing forests is difficult because it takes many years for a variety of trees, shrubs, and herbs to reach maturity and restore the complex ecosystem that supports a diversity of wild animals, birds, and insects.

7. Make a list of five daily activities in which you use natural resources. Suggest ways by which you can reduce their use.

1. Drinking water: Turn off the tap while brushing teeth.
2. Using electricity: Switch off lights and fans when not in use.
3. Using vehicles: Use public transport, walk, or cycle for short distances.
4. Cooking: Use energy-efficient stoves or solar cookers.
5. Using paper: Use both sides of a paper and recycle old books.

8. List four activities that are possible due to the presence of air.

1. Breathing (survival of living beings).
2. Generating electricity using windmills.
3. Flying birds and airplanes.
4. Dispersion of seeds and pollination.

9. How can you contribute towards enhancing the green cover of your locality? Make a list of actions to be taken.

• Planting native trees and shrubs in the community.
• Participating in Van Mahotsav programs.
• Ensuring that plants in the neighborhood are watered and protected.
• Raising awareness about the importance of forests.

10. Answer the following questions based on the illustration where food is being cooked in a solar cooker:

• (i) What type of energy is being used for cooking? Solar energy (heat from the Sun).
• (ii) Name one benefit and one drawback of using this type of energy for cooking.
  • Benefit: It is a free, renewable, and non-polluting source of energy.
  • Drawback: It can only be used during sunny days and takes longer to cook than conventional methods.

11. Cutting down trees on a large scale impacts the quality of the soil. Why do you think it is so? Trees prevent soil erosion as their roots hold the soil particles together. Without trees, the top fertile layer of the soil is easily washed away by rain or wind. Also, decaying leaves from trees enrich the soil with nutrients, which stops when trees are removed.

12. Explain two ways in which human activities pollute the air. Propose one action which can help in reducing air pollution.

• Human Activities: Burning fossil fuels in vehicles and industries, and burning of waste.
• Proposed Action: Transitioning to electric vehicles (EVs) or using public transport to reduce the amount of smoke and pollutants released into the air.

13. A family uses solar panels, a gas stove, and a windmill. What would happen if there were no sunlight for a week? If there were no sunlight for a week:

1. The solar panels would not be able to generate electricity.
2. The family would have to rely on alternative sources of electricity.
3. The gas stove would still work as it uses fossil fuel (LPG/Natural gas).
4. The windmill would continue to function as long as there is wind, which is independent of direct sunlight.

14. Fill up the blanks using the following terms—

• (Natural Resources → Renewable Resources (e.g. Water, Forest, Air) → Non-renewable Resources (e.g. Fossil fuels like Coal, Petroleum, and Natural Gas))

15. Discuss the felling of trees for industrial/housing requirements. Felling trees on a large scale for industries or housing is not entirely justified because it leads to habitat loss, soil erosion, and climate change. Sustainable development should focus on building without destroying the existing green cover or ensuring compensatory afforestation.

16. Propose a plan to use less water in your school.

• Plan: Install sensor-based taps to prevent wastage, implement a rainwater harvesting system to water the school garden, and conduct awareness workshops for students on the importance of saving every drop.
• Effect: This would reduce the school's dependence on freshwater sources and help conserve a vital natural resource for the future.