NCERT Solutions for Class 9 Science Chapter 14 Natural Resources

1. Why is the atmosphere essential for life?

Answer: Atmosphere is important because –

• It keeps average temperature of earth constant.
• Prevents sudden change in temperature due to heat of the sun.
• It prevent heat escape from the earth’s atmosphere into outer space.

2. Why is water essential for life?

Answer:

1. Water is essential for transportation of biological processes inside the body.
2. In the body various biological reaction takes place when substances are dissolved in water. Moreover, all cellular process needs water as a medium.

3. How are living organisms dependent on the soil? Are organisms that live in water totally independent of soil as a resource?

Answer: Almost all organisms are dependent on the soil directly or indirectly. Plants grow in soil and acquire nutrients from the soil. Animals and other living organisms consume plants. Organisms living under water are not directly dependent on sol. However, these organisms are dependent on aquatic plants with are dependent on soil.

4. You have seen weather reports on television and in newspapers. How do you think we are able to predict the weather?

Answer: Weather department of government collect data on various parameter like temperature, humidity, wind speed and rainfall. This data is gathered from various instruments. Minimum and maximum temperature is predicted using thermometer. Rainfall is predicted using rain gauge. Wind speed is measured using anemometer and humidity is measured using psychrometer.

5. We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?

Answer: Yes, isolating human activities to specific and limited areas will help in reducing pollution. For example, setting up industries and factories in isolated region will reduce air pollution. Also it will prevent contamination of water sources, land fertility, etc.

6. Write a note on how forests influence the quality of our air, soil and water resources.

Answer: Following are some ways how forest influence the quality of our air, soil and water resources.

• Forests take carbon dioxide thereby reducing air pollution. This carbon dioxide is used by plants in forest for various processes and in return it releases large amount of oxygen into the atmosphere.
• Forest prevents soil erosion, as roots of trees in forest holds soil firmly.
• Helps in replenishing water resources. Transpiration releases lots of water vapor in the atmosphere, which forms clouds and thereby further causing rainfall that recharges water bodies.

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