Students can download Class 8 Science Chapter 1 Natural Resources Important Questions, KSEEB Class 8 Science Important Questions and Answers helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.
Karnataka State Syllabus Class 8 Science Important Questions Chapter 1 Natural Resources
Question 1.
What is a resource?
Answer:
Anything that can be used to satisfy a need is a resource.
Question 2.
What are natural resources?
Answer:
Resources that are found in nature that support life and contribute to our development are known as natural resources. Natural resources are those resources in nature that support our needs and wants.
Question 3.
What is the basis for classifying natural resources as biotic resources and abiotic resources?
Answer:
Natural resources are classified as biotic resources and abiotic resources depending on whether they
are obtained from living sources or non-living sources in nature.
Question 4.
What are living natural resources? Give examples.
Answer:
Natural resources obtained from living organisms are called living natural resources. Living natural resources include forests and forest products, animals and animal products and microbes.
Question 5.
What are non-living natural resources? Give examples.
Answer:
Natural resources obtained from non-living sources are called non-living natural resources. Non-living natural resources include sunlight, air, water, soil and fossil fuels.
Question 6.
Classify the following as biotic resources and abiotic resources: Land, wildlife, air, timber, fossil fuels and leather.
Answer:
- Biotic resources: Wildlife, timber, leather
- Abiotic resources: Land, air, fossil fuels.
Question 7.
What are renewable natural resources? Give examples.
Answer:
Those natural resources which get replenished through natural processes within a reasonable period of time and hence can be used continuously are known as renewable natural resources. E.g. Water, wildlife, forests etc.
Question 8.
What are non-renewable natural resources? Give examples.
Answer:
Those natural resources which do not get replenished through natural processes within a reasonable period of time and hence get depleted with continuous use are called non-renewable natural resources. E.g. Fossil fuels, minerals, etc.
Question 19.
What are inexhaustible natural resources? Give an example.
Answer:
Natural resources which get renewed through natural processes do not get depleted with continuous use. These resources would be available for continuous use. Such resources are called inexhaustible natural resources.
E.g. Air, water, soil, etc.
Question 10.
What are exhaustible natural resources? Give an example.
Answer:
Natural resources which do not get renewed through natural processes will get depleted with continuous use. Such resources which get exhausted with continuous use are called exhaustible natural resources.
E.g. Minerals, coal, petroleum, etc.
Question 11.
Distinguish between renewable natural resources and non-renewable natural resources.
Answer:
The natural resources which get regenerated by nature and hence never get exhausted after a reasonable period of time are called renewable resources. E.g. sunlight, oxygen.
The natural resources which once used up and cannot be replaced within a reasonable period of time are called non-renewable resources. E.g. coal, petroleum, natural gas.
Question 12.
Describe the importance of natural resources.
Answer:
Natural resources are naturally-occurring substances that are useful and essential to us. The value of a natural resource depends on the amount of the resource available and the demand for it. The demand is determined by its usefulness. The basic needs of life are fulfilled by materials like air, water, soil, minerals, coal, petroleum, animals and plants found in nature.
The natural resources are vital for survival and development. Natural resources play an important role in the development of a nation. They influence the economy. A country which is rich in natural resources may achieve rapid economic development while those which do not have them may not progress fast. A country with meagre natural resources might face serious economic problems.
Question 13.
Why are fossil fuels considered as non-renewable natural resources?
Answer:
Fossil fuels are formed in the interior of the earth over millions of years. They are not replenished through natural processes within a reasonable period of time. Hence, fossil fuels are non-renewable natural resources.
Question 14.
What is water pollution? List the causes of pollution of water.
Answer:
Water pollution is the lowering of the quality of water due to addition of organic and inorganic materials making water less fit or unfit for use.
Water pollution is caused by industrial effluents, agricultural wastes, use of pesticides, chemical fertilizers, improper management of sewage, spillage of grease and oil, etc.
Question 15.
Why is water considered a scarce resource?
Answer:
About 71% of the surface of the earth is covered with water. However, only a small percentage of it is fit for use by living organisms. About 97% of the water available on earth is in the oceans. This water is unfit for use because it is salty. A large part of the remaining 3% of water is stocked in the form of ice in the Polar regions. Only less than 1% of the water on earth is supporting living organisms. Hence, water is considered a scarce resource.
Question 16.
What is meant by conservation of water? Why is it necessary?
Answer:
The effort made by the society towards rational use, prevention of pollution and recycling of water is known as conservation of water. Conservation of water is necessary because less than 1% of the total water on earth is available for the consumption of living beings.
The demand for water is continuously increasing. There is acute shortage of water for human activities and for other living beings. Therefore, we must conserve water.
Question 17.
Mention the human activity for which highest amount of water is consumed.
Answer:
The largest use of water occurs in the agricultural sector. In our country for example, 80% of the total water available for human use is used for agricultural activities.
Question 18.
List the uses of water.
Answer:
Water has many uses. Some of these uses are given below:
- Water is used for drinking and cooking food.
- It is used for washing and bathing.
- Water is essential for building construction and other construction activities.
- It is used for the generation of steam for industrial use and electricity generation.
- It is used for generating hydroelectricity.
- Water is most essential for agriculture.
- It is used for heat exchange processes and in fire extinguishers.
Question 19.
When is world water day observed every year? What is its significance?
Answer:
International World Water Day is observed all over the world every year on March 22. The purpose of observing this day is to focus the attention of the people on the importance of freshwater and for advocating sustainable management of freshwater resources.
Question 20.
What is soil? What is it made up of?
Answer:
The topmost layer of the earth’s surface is called soil. It is a mixture of air, water, minerals and organic substances.
Question 21.
How is soil formed?
OR
What is weathering?
Answer:
Soil is formed over a long period of time by a natural process called weathering of rocks and minerals. During weathering, the bigger rocks break into small pieces and form soil. Soil formation takes place when many things interact, such as air, water, plant life, animal life, rocks, and chemicals. Over time this creates a thin layer of soil.
Question 22.
List some of the uses of soil.
Answer:
Soil is a natural resource that provides minerals and water to all land plants. It is a primary nutrient base particularly for agricultural crops. In addition, it is the place of living for a wide variety of organisms like earthworms, crabs, insects and micro organisms. Soil absorbs rain water. This water is used by plants. Water gets purified as it percolates through soil.
Question 23.
What is salination of soil?
Answer:
The process of excessive accumulation of water soluble salts in the soil to the extent that the fertility of the soil is reduced is known as salination of soil.
Question 24.
What is waterlogging of soil? Give two reasons for waterlogging.
Answer:
The saturation of the soil with ground water to the extent that it hinders plant growth and agriculture is known as waterlogging of soil. Waterlogging occurs when the soil is saturated with water. One important factor that causes waterlogging of soil is the nature of the soil itself. Heavy soils are most likely to waterlog. They have limited pore space through which water and air can move only very slowly. Proper drainage is essential to prevent waterlogging.
Question 25.
What is desertification? What are its causes?
Answer:
The rapid depletion of plant life and the loss of topsoil resulting in a given fertile land area becoming barrers is known as desertification.
Destruction of green cover over land, defective agricultural practices, unscientific irrigation of farm land, overgrazing, water logging, salination are some of the causes of desertification.
Question 26.
What is soil erosion? How is it caused?
Answer:
The removal of the top soil by water, tillage or wind is known as soil erosion. Soil erosion occurs both through natural factors and human activities. However, humans play a major role in soil erosion through their use and abuse of soil. Human activities that cause soil erosion include deforestation and overgrazing.
Question 27.
Mention any two natural agents that cause soil erosion.
Answer:
Wind and water are two agents that cause soil erosion.
Question 28.
What are forests? Explain the importance of forests as a natural resource.
Answer:
A forest is a complex ecosystem or assemblage of ecosystems dominated by trees and other woody vegetation spread over a large area. Forests and trees are a crucial part of life on Earth. They help to maintain biodiversity and clean up the air and water.
They maintain water cycle, control weather and climate. They are the habitats to many wild life. They maintain soil quality by preventing soil erosion. They provide timber and many other products and services. They provide raw materials for many industries. They also contribute to culture and recreation.
Question 29.
A student argues that a nation will be rich if its forests are conserved. Explain.
Answer:
Forests provide a wide range of goods and services that contribute to the socio-economic development of the nation. Forests have obvious economic significance through the provision of timber and wood. In addition, non-timber products like rubber, cotton, medicinal products, and food represent significant economic value. Forests also provide employment to millions of people.
Forests play a very important role in rainfall, soil fertility and climatic changes. These, factors are crucial for economic progress. The forests will also make our environment beautiful and people will become culturally rich. Therefore, the student is right when he says that a nation will be rich if its forests are conserved.
Question 30.
On which day of every year do we observe World Forest Day? What is its significance?
Answer:
World Forest Day is observed all over the world on March 21 every year. This is to respect the contribution of the forests to the welfare of living beings including the humans. It is also an opportunity to educate people about the importance of forests and the need for conserving them.
Question 31.
What is wildlife?
Answer:
The term ‘wildlife’ refers to all the plants and animals on earth that are not domesticated or cultivated by humans. They refer to the species of plants and animals found in the forest. Wildlife includes all living organisms in their natural habitat other than cultivated plants and domesticated animals.
Question 32.
Mention some human activities that are detrimental to wildlife.
Answer:
Deforestation, illegal wildlife trade, hunting, poaching, climate changes, forest fires, habitat loss are some of the human activities that are threatening wildlife.
Question 33.
What is conservation of wildlife? Mention the steps that can be taken to protect wildlife.
Answer:
The practice of protecting endangered plant and animal species and their habitats is known as conservation of wildlife. Creating public awareness, protecting the habitat and maintaining the natural habitats, creation of national parks and wildlife sanctuaries, conservation of forests, captive breeding, creation of seed banks and gene banks are some of the measures that can be taken to protect wildlife.
Question 34.
What are fossil fuels? Give examples.
Answer:
Fuels formed in the interior of the earth over millions of years from the remains of ancient plants and animals are called fossil fuels. E.g. Petroleum, coal and natural gas.
Question 35.
Why is coal considered a fossil fuel?
Answer:
Coal is called a fossil fuel because it was formed from the remains of vegetation that grew on earth million of years ago.
Question 36.
Mention the various types of coal. How do they differ from one another?
Answer:
Some of the major types of coal are Peat, Lignite, Anthracite and Bituminous coal. The various types of coal differ in their carbon content, density and calorific value.
Question 37.
Give the carbon composition of various types of coal.
Answer:
- Anthracite – About 80%
- Lignite – About 50 to 65%
- Peat – About 40%
- Bitumin – Less than 40%.
Question 38.
What is the effect of overuse of fossil fuels?
OR
Why should we conserve fossil fuels?
OR
What happens if too much of fossil fuels are used?
Answer:
Fossil fuels are non-renewable resources. We will be carrying the risk of fossil fuels running out of stock if we use them indiscriminately. This may lead to a crisis. Secondly, burning of fossil fuels creates many hazards which includes air pollution, global warming, acid rain and fog. Therefore, we must avoid overuse of fossil fuels and conserve them.
Question 39.
What are mineral resources?
Answer:
Non-renewable natural resources found in the earth’s crust are known as mineral resources.
Question 40.
What is mining?
Answer:
The process of extracting ore or minerals from the earth’s crust is called mining.
Question 41.
Mention some of the substances for which mining is done.
Answer:
More than 100 minerals including metals like gold, iron, copper and aluminium and materials like sand and salt are extracted from the earth through mining.
Multiple Choice Questions
Question 1.
Which of the following is a renewable resource?
(a) Soil
(b) Water
(c) Minerals
(d) All of the above
Answer:
(b) Water
Question 2.
A non-renewable source of energy is
(a) Wildlife
(b) Fossil fuels
(c) Water
(d) Forest
Answer:
(b) Fossil fuels
Question 3.
Inexhaustible resource among the following is
(a) Minerals
(b) Coal
(c) Solar energy
(d) Petroleum
Answer:
(c) Solar energy
Question 4.
Which one of the following is not a fossil fuel?
(a) Natural gas
(b) Petrol Fresh
(c) Coal
(d) Uranium
Answer:
(d) Uranium
Question 5.
Fresh water present on earth is about
(a) 3.0%
(b) 97.0%
(c) 0.01%
(d) 0.3%
Answer:
(a) 3.0%
Question 6.
Natural resources which have definite cycle are
(a) Exhaustible Non-renewable
(b) Inexhaustible
(c) Non-renewable
(d) Exhaustible Renewable
Answer:
(b) Inexhaustible
Question 7.
More than 70% of world’s fresh water is contained in
(a) Ponds
(b) Glaciers and polar ice caps
(c) Greenland
(d) Oceans
Answer:
(b) Glaciers and polar ice caps
Question 8.
Chipko movement is related to
(a) Forest conservation
(b) Soil conservation
(c) Water conservation
(d) Wetland conservation
Answer:
(a) Forest conservation
Question 9.
Deforestation brings about
(a) Weed control
(b) Decreases drought
(c) Soil erosion
(d) Increased sunlight
Answer:
(c) Soil erosion
Question 10.
Deforestation is the major causal agent of
(a) Depletion of natural resources
(b) Environmental pollution
(c) Weathering
(d) Desertification of habitat
Answer:
(d) Desertification of habitat
Question 11.
Deforestation will decrease
(a) Soil erosion
(b) Landslides
(c) Soil fertility
(d) Rainfall
Answer:
(c) Soil fertility
Question 12.
Floods can be prevented by
(a) afforestation
(b) cutting the forests
(c) tilling the land
(d) removing the top soil
Answer:
(a) afforestation
Question 13.
Extensive planting of trees to increase forest cover is called
(a) Deforestation
(b) Agro forestry
(c) Social forestry
(d) Afforestation
Answer:
(d) Afforestation
Question 14.
Main cause of extinction of species in tropical areas is
(a) Afforestation
(b) Deforestation
(c) Pollution
(d) Soil erosion
(b) Deforestation
Answer:
(b) Deforestation
Question 15.
Maximum use of fresh water is in
(a) Agriculture
(b) Domestic use
(c) Industry
(d) Pisciculture
Answer:
(a) Agriculture
Question 16.
Which one of the following does not belong to the group?
(a) water
(b) forests
(c) petrol
(d) soil
Answer:
(c) petrol
Question 17.
Government has banned hunting of wild animals. This is to
(a) maintain biodiversity
(b) promote tourism
(c) provide food to animals
(d) maintain soil fertility
Answer:
(a) maintain biodiversity
Fill In The Blanks
1. Resources that get replenished in nature are called renewable resources
2. If there is rise in water table, soil becomes waterlogged
3. Air and water are examples of resources, renewable natural
4. The loss of top soil is known as soil erosion
5. The type of coal that has highest percentage of carbon is Anthracite
6. Soil provides and to terrestrial plants, support, nutrients
7. Petroleum, coal and natural gas are together known as fossil fuels
8. Formation of soil occurs by a process called weathering of rocks
9. Petrol and kerosene are forms of natural resources, non-renewable
10. World Water Day is observed on March 22nd
Match The Following
Question 1.
| A | B |
| 1. Coal with high carbon content | a. Lignite |
| 2. A renewable natural resource | b. Bitumin |
| 3. A fuel with low sulphur content | c. Wind |
| 4. Formation of soil | d. LPG |
| e. Weathering of rocks | |
| f. Anthracite | |
| g. Natural gas |
Answer:
1 – f, 2 – c, 3 – g, 4 – e.