Natural Resources: Chapter 14 Questions and Answers for Class 9 (CBSE/NCERT)
Resources are anything that humans may utilise to fulfil their needs and desires. Natural resources are those that are directly accessible from nature and can be used by humans.
A straightforward definition of a natural resource is “Resources that exist independently of human intervention.”
Natural resources, according to WTR (2010), are “stocks of materials existing in the natural environment that are both scarce and economically usable in production or consumption, either in their raw state or with a minimal amount of processing.”
Question: Why is the atmosphere essential for life?
Ans: Because of the following, the atmosphere is necessary for life
As a result, the average temperature of the earth is kept generally stable, preventing a dramatic rise in temperature during the day and slowing down the departure of heat into space during the night. In this way, the environment serves as a blanket. It contains a variety of gases that are necessary for life to exist on earth. Through its ability to block UV rays from reaching the earth’s surface, the ozone layer shields the planet from dangerous solar radiation. The movement of air in the atmosphere causes winds to be created, and these winds determine when it will rain and how much. Without an atmosphere, the water cycle is insufficient.
Question: Why is water essential for life?
Ans: The following justifications make water necessary
About 60 to 70 percent of our body is made up of water. All bodily metabolic processes require water to function. It serves as a conduit for the movement of materials inside the body. It supports preserving body temperature.
Question: How are living organisms dependent on the soil?
Ans: For the following reasons, the soil is essential to all living things:
(i) The ecosystem’s producers are the plants, who provide the food for practically all living things. They develop in the soil because it supplies them with water and mineral nutrients.
(ii) Forests, which give us wood, construction materials, fibre, and medicinal plants, are supported by soil. Numerous animal species have forests as their natural environment.
(iii) Numerous creatures and insects live in the soil.
In terms of resources, the soil is used by organisms that live in water. In dissolved form, the minerals that make up nutrition are found in water. However, the decomposers that exist in the soil assist in their recycling. Minerals come from the soil into water bodies like rivers. In addition, until rocks are turned into soil, the minerals trapped in them cannot reach aquatic life.
Question: You have seen weather reports on television and in newspapers. How do you think we can predict the weather?
Ans: The atmosphere’s condition at a certain location and time is the weather. The wind’s strength and direction, temperature, air pressure, rainfall, and relative humidity are only a few of the factors that affect a location’s weather. By using remote sensing and weather forecasting satellites, the meteorological service gathers all of this data. An updated weather report resulted from these signals. We can predict the weather of a location thanks to this common knowledge.
Question: 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?
Ans: Because air, water, and soil are interconnected, focusing on just one human activity that causes pollution will not help. They cannot be constrained to a specific location. When a given pollutant, like CO2, is present in the air in a particular place, the air will become warmer. Diffusion is how the air spreads to the surrounding locations. As a result, CO2 will disperse in the atmosphere. Additionally, other air contaminants dissipate in the atmosphere. The amount of dissolved oxygen in water declines as a result of water pollution. Aquatic life forms eventually perish as a result. In several other locations, the food chains and food webs are impacted by this disease. As a result, the problem of pollution cannot be remedied by confining various human activities to certain regions.
Question: Write a note on how forests influence the quality of our air, soil and water resources?
Ans: Our air, soil, and water resources are all impacted by forests in the following ways:
(i) Forests keep the ratio of oxygen to carbon dioxide in check. Forest plants use CO2 for photosynthesis, which also results in the release of oxygen. As a result, trees give back the oxygen used during respiration and combustion. Forests stop soil erosion
(ii) Plants’ roots cling to the soil firmly and guard against erosion. The speed of the wind and the flow of water is also monitored by forest trees.
(iii) Forests are necessary for restoring water supplies as well. Through transpiration, they are vital to maintaining the water cycle. Thus, trees have an impact on the soil, water, and air quality.
Question: How does the atmosphere act as a blanket?
Ans: Air, which is a poor conductor of heat, makes up the earth’s atmosphere. The atmosphere prevents the abrupt change in temperature between day and night. Thus, the atmosphere keeps the earth’s average temperature constant.
Question: What causes winds?
Ans: The unequal heating of atmospheric air in various places of the globe is what causes the wind. More frequently observed throughout the daylight in coastal areas. In comparison to air over water, the air above land warms up more quickly. A low-pressure area is formed as the air over the land rises, and the chilly air over the sea quickly fills it. The air over land similarly travels to the sea during the night. The wind is produced by these air motions.
Question: How are clouds formed?
Ans: Tiny water droplets and ice crystals make up clouds. Heat causes water from several sources to evaporate and enter the atmosphere. Water vapour rises in the atmosphere and is joined by warm air. Condensation of the water vapour occurs as a result of the ascending air cooling and condensing. In and around airborne dust particles, water vapour condenses into small droplets. These little droplets get larger as they condense with other droplets to produce clouds.
Question: List any three human activities that you think would lead to air pollution.
Ans: The top three causes of air pollution are as follows: Deforestation is one problem, while smoke from factories and cars is another. Overuse of fossil fuels like coal and petroleum is a factor.
Question: Why is water important for living organisms?
Ans: Water’s significance:
(i)The human body contains between 60 and 70 percent water.
(ii) Water dissolves all of the compounds that are carried throughout the body.
(iii) Water is an essential element in all metabolic processes.
Question: What is the major source of fresh water in the city/town/village where you live?
Ans: In my city, underground water is a significant supply of fresh water. Depending on the situation, it is removed using either handholds or tube wells.
The municipal department stores the water extracted from tube wells in sizable tanks, and various homes are supplied with it via pipelines from those tanks. Rivers and ponds are other sources of fresh water in addition to subsurface water.
Question: Do you know of any activity which may be polluting this water source?
Ans: (i)Factory waste and sewage discharge into water bodies are actions that contribute to water pollution.
(ii) Using rivers and ponds as bathing and laundry facilities.
(iii) Hot water discharged from cooling towers into rivers has an impact on aquatic life.
Question: How is soil formed?
Ans: Rock weathering results in the formation of soil. Living things, including the sun, water, wind, and water, are essential to this process. Because of the sun’s rays, sun-formed rocks enlarge during the day and cool and contract at night. Rocks gradually break down due to the constant expansion and contraction that causes cracks. Water: Either by rapid flow or freezing, water aids in the creation of soil. Water expands and fractures rocks when it freezes in soil crevices. Rapid water flow causes rocks to slowly deteriorate and moves soil particles to new locations. Storms and strong winds further break rocks, which helps in soil transport to other locations. Living organisms: Lichens that grow on rock surfaces exude chemicals that break down the rocks into powder and cause the creation of a thin layer of soil. On the surface of rocks, mosses and other tiny plants flourish, which causes the rocks to crack even more.
Question: What is soil erosion?
Ans: Soil erosion refers to the loss of rich topsoil.
Question: What are the methods of preventing or reducing soil erosion?
Ans: Avoiding overgrazing, planting trees, contour ploughing, planting vegetation to cover the soil, and using chemical fertilisers sparingly can all help to reduce soil erosion.
Question: What are the different states in which water is found during the water cycle?
Ans: In the water cycle, water exists in three phases solid, liquid, and gas (water vapour).
Question: Name two biologically important compounds that contain both oxygen and nitrogen.
Ans: The two physiologically significant molecules that contain both oxygen and nitrogen are proteins and nucleic acids (DNA and RNA).
Question: List any three human activities which would lead to an increase in the carbon dioxide content of the air.
Ans: Burning fossil fuels, industrialization, and deforestation are the three human actions that increase the amount of carbon dioxide in the atmosphere.
Question: What is the greenhouse effect?
Ans: The greenhouse effect is caused by an increase in the proportion of gases in the atmosphere that traps heat, raising global average temperatures.
Question: What are the two forms of oxygen found in the atmosphere?
Ans: There are two types of oxygen in the atmosphere:
(i) Diatomic molecules (O2) that can be found in the lower atmosphere. (ii) Triatomic molecules, or ozone (O3), which are abundant in the high atmosphere.