Chapter 14 . Natural Resources

Class 9 Science Chapter 14 . Natural Resources Internal Questions and Answers :

Internal Questions :

1. How is our atmosphere different from the atmospheres on Venus and Mars?

Answer : Our atmosphere has more oxygen and is suitable for humans. Venus has a thick, hot, and poisonous atmosphere, while Mars has a thin, cold atmosphere with little oxygen.
2. How does the atmosphere act as a blanket?

Answer : The atmosphere acts like a blanket by trapping heat from the sun, keeping Earth warm enough for life.
3. What causes winds?

Answer : Winds are caused by the movement of air, driven by differences in temperature and pressure.
4. How are clouds formed?

Answer : Clouds are formed when water vapor in the air cools and condenses around tiny particles like dust or ice crystals.
5. List any three human activities that you think would lead to air pollution.

Answer : Three human activities that can lead to air pollution are:

(i) Burning fossil fuels (like in cars and factories)

(ii) Industrial emissions

(iii) Deforestation and land-use changes

Internal Questions :

1. Why do organisms need water?

Answer : Organisms need water to live because it's essential for their survival, helps control their temperature, and allows them to move nutrients and waste in their bodies.
2. What is the major source of fresh water in the city/town/village where you live?

Answer : The main source of fresh water in most places is rivers or underground wells.
3. Do you know of any activity which may be polluting this water source?

Answer : Yes, some people in our area dispose of trash and chemicals into the river, which can pollute the water source.

Internal Questions :

1. How is soil formed?

Answer : Soil is formed through the gradual weathering and breakdown of rocks and minerals over time. This process involves the physical, chemical, and biological actions of weather, water, wind, and living organisms. As rocks break down and organic matter accumulates, soil develops in layers, with the top layer being the most fertile and suitable for plant growth.
2. What is soil erosion?

Answer: Soil erosion is the process where soil is gradually worn away and removed from one location to another by natural forces such as wind, water, or human activity. It can result in the loss of fertile topsoil, which is essential for plant growth, and can lead to land degradation and reduced agricultural productivity.
3. What are the methods of preventing or reducing soil erosion ?

Answer :  Methods of preventing or reducing soil erosion includes are :

 (i) Planting trees, grass, and cover crops helps hold soil in place with their root systems.

(ii) Plowing and planting crops along the contours of the land to reduce water runoff.

(iii) Building terraces or steps on hilly terrain to slow water flow and trap soil.

(iv) Applying mulch, like straw or organic materials, on the soil surface to protect it from erosion.

(v) Reducing or eliminating plowing to keep crop residues on the soil, preventing erosion.

(vi) Installing barriers to trap sediments in runoff water.

(vii) Managing water flow through channels, ditches, or culverts to prevent erosion.

Internal Questions :

1. What are the different states in which water is found during the water cycle?

Answer:  Water undergoes different states during the water cycle are :

Liquid: Water exists in the liquid state as lakes, rivers, and oceans.

Gas: Water evaporates, transforming into water vapor, which is a gaseous state present in the atmosphere.

Solid: Water condenses and freezes into ice, forming solid-state glaciers, snow, and ice caps.

Precipitation: Water falls back to Earth as rain, snow, sleet, or hail, completing the water cycle.
2. Name two biologically important compounds that contain both oxygen and nitrogen.

Answer: Amino Acids and DNA (Deoxyribonucleic Acid) .
3. List any three human activities which would lead to an increase in the carbon dioxide content of air.

Answer:  Three human activities that contribute to an increase in carbon dioxide content in the air are:

Burning of fossil fuels: Combustion of coal, oil, and natural gas for energy production and transportation releases carbon dioxide into the atmosphere.

Deforestation: Clearing forests, particularly through burning, reduces the capacity of trees to absorb carbon dioxide, resulting in its accumulation in the atmosphere.

Industrial processes: Certain manufacturing and industrial processes, such as cement production, release significant amounts of carbon dioxide as a byproduct.

4. What is the greenhouse effect?

Answer: The greenhouse effect is a natural process in which certain gases in the Earth's atmosphere, such as carbon dioxide and methane, trap heat from the sun. This trapped heat warms the Earth's surface and lower atmosphere, creating a stable and habitable climate. However, human activities have enhanced the greenhouse effect, leading to global warming and climate change.
5. What are the two forms of oxygen found in the atmosphere?

Answer:  The two forms of oxygen found in the atmosphere are molecular oxygen (), which makes up approximately 21% of the atmosphere, and ozone () found in the ozone layer.

Class 9 Science Chapter 14 . Natural Resources Exercise Questions and Answers :

1. Why is the atmosphere essential for life?

Answer: The atmosphere is essential for life due to the following reasons :

(i) It contains oxygen, which is vital for respiration and the survival of most organisms.

(ii) It protects life on Earth by absorbing harmful ultraviolet radiation from the Sun.

(iii) It helps regulate temperature by trapping heat and preventing extreme temperature variations.

(iv) It provides a medium for weather and climate patterns, which are crucial for the functioning of ecosystems.

2. Why is water essential for life?

Answer:  Water is essential for life due to the following reasons :

(i) It is a universal solvent and facilitates various biochemical reactions within living organisms.

(ii) It helps maintain temperature regulation in organisms through its high specific heat capacity.

(iii) It acts as a medium for transportation of nutrients, gases, and waste products within living systems.

(iv) It provides a habitat for many organisms and supports biodiversity.

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

Answer : Living organisms are dependent on soil in different ways:

(i) Soil provides a medium for plant growth and serves as a source of nutrients, water, and anchorage for roots.

(ii) Many organisms, such as earthworms and bacteria, help in nutrient recycling and decomposition processes, enhancing soil fertility.

(iii) Some organisms, like burrowing animals, rely on soil for shelter and protection.

Organisms that live in water are not entirely independent of soil as a resource. Although water-based organisms do not directly depend on soil for their survival, the quality of aquatic habitats can be influenced by sediment and nutrient runoff from soil. Additionally, aquatic ecosystems often interact with adjacent terrestrial ecosystems, where soil plays a crucial role in supporting land-based organisms and influencing water quality through nutrient cycling and filtration processes.

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

Answer: Weather prediction is possible through a combination of various scientific methods and technologies. Meteorologists gather data from weather stations, satellites, and weather balloons, measuring parameters such as temperature, humidity, air pressure, wind speed, and cloud patterns. This data is then analyzed using computer models to make forecasts based on patterns and trends observed in the atmosphere.

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: Isolating polluting activities to specific and limited areas can be a useful strategy in reducing pollution, but it has limitations. While it can help contain and control pollution in those isolated areas, it does not address the larger issue of overall environmental impact. Pollutants can still disperse through air and water, affecting neighboring regions and ecosystems. Therefore, a comprehensive approach that combines pollution control measures, sustainable practices, and environmental regulations is necessary to effectively reduce pollution on a broader scale.
6. Write a note on how forests influence the quality of our air, soil and water resources.

Answer:  Forests play a vital role in influencing the quality of our air, soil, and water resources.

In terms of air quality, forests act as natural filters by absorbing carbon dioxide and releasing oxygen through photosynthesis, reducing the concentration of greenhouse gases. They also help trap airborne pollutants, improving air quality.

Regarding soil, forests contribute to soil health by preventing erosion, promoting organic matter accumulation, and enhancing nutrient cycling. The forest floor provides a natural layer of protection, preventing soil erosion and maintaining soil fertility.

Forests also play a crucial role in water resources. Tree canopies intercept rainfall, reducing the impact of erosion and runoff. The root systems of trees help in water infiltration, preventing soil erosion and maintaining water quality by filtering pollutants. Forests also regulate water flow, reducing the risk of floods and maintaining stable water supplies.