Natural Resources Class 9 Important questions and answers
Given below are the Class 9 Science Important Questions and worksheets for Natural Resources
(a) Multiple choice questions
(b) Fill in the blank's
(c) Very Short Answer type
(d) Short Answer type
(e) Long Answer type
Multiple Choice Questions
Question 1.
Major source of mineral in soil is the
(a) parent rock from which soil is formed
(b) plants
(c) animals
(d) bacteria Question 2.
Total earth’s surface covered by water is
(a) 75%
(b) 65%
(c) 85%
(d) 51% Question 3.
Biotic component of biosphere is not constituted by
(a) producers
(b) consumers
(c) decomposer
(d) air Question 4.
The two forms of oxygen found in the atmosphere are
(a) water and ozone
(b) water and oxygen
(c) ozone and oxygen
(d) water and carbon-dioxide Answers
1.(a)
2.(a)
3.(d)
4. (c)
Fill in the blanks
Question 5.
(i)The ____, _____ and ____ form the non-living or abiotic component of the biosphere
(ii)Higher concentrations of _____is one of the causes of green house effect/global warming.
(iii)______is the biological process by which water is lost in the form of water vapour from the aerial parts of the plants called stomata.
(iv) _____ gas makes up 78% of our atmosphere Answers
(i)air, the water and the soil
(ii)CO2
(iii)Transpiration
(iv)Nitrogen
Very Short Answer
Question 6.
Write the name of any two air pollutants? Answers
Carbon monoxide (CO)
Sulphur dioxide (SO2)
Question 7.
Name the substance made by nitrogen? Answers
Nitrogen dioxide (NO2)
Question 8.
Name the bacteria which help in nitrogen fixation? Answers
A species of bacteria called Rhizobium
Question 9.
Write the process in which O2 is used? Answers
Combustion
Question 10.
Write the name of greenhouse gases? Answers
Methane, Carbon dioxide , Ozone
Question 11.
Name the substance which damages the ozone layer? Answers
When water bodies are heated during the day, a considerable amount of water evaporates and enters the atmosphere. Water vapour is also released into the atmosphere as a result of biological processes. This air is also heated. The warm air rises, carrying with it the water vapour. The rising air cools down and expands. As a result of this cooling, the water vapour in the air condenses into small droplets. Water condensation is aided if some particles act as the 'nucleus' around which these drops form. This function is normally performed by dust and other suspended particles in the air.
The 'condensation' of these water droplets causes them to grow larger once produced. These are called clouds .When the drops have become large and heavy, they fall to the ground like rain.
Some gases hinder heat from escaping from the Earth. An increase in the amount of such gases in the atmosphere would cause global average temperatures to rise, which is known as the greenhouse effect.
Question 14.
What are biogeochemical cycles? Answers
The cycle of transfer of matter and energy between the the biotic and abiotic components of the biosphere is called the biogeochemical cycles.
The cycles are Carbon cycle, Nitrogren cycle and water cycle
Question 15.
How is greenhouse effect related to global warming? Explain? Question 16.
What are the three ways by which CO2 is returned back into atmosphere? Answers
Respiration by plants and animals
Combustion of fuels
decomposition of dead organic matter.
Question 17.
Why does Mathura refinery pose problems to the Taj Mahal? Answers
Refinery release sulplur dioxide in the atmosphere. sulplur dioxide combines with water to form sulphuric acid and which cause acid rain and it destroy the quality of the marble
Question 18.
Write the name of the triatomic molecule of oxygen?
(a)Is its presence necessary in the nature?
(b)How does it affect the environment? Explain? Answers
Ozone
Yes, it saves us from ultravoilet rays
Question 19.
Suggest any two ways for conservation of water and mention any three traditional methods of doing so? Question 20.
What is sea breeze and land breeze? Answers
When we look at the situation in coastal regions throughout the day, we can see that the air above the land heats up faster and begins to rise. As this air rises, a region of low pressure forms, and air over the sea moves into this region of low pressure. Winds are caused by the movement of air from one location to another. During the day, the wind would be blowing from sea to land and this is called sea breeze
During the night, both land and sea start to cool. Since water cools down slower than the land, the air above water would be warmer than the air above land,So it create a low pressure region in sea and then winds happens from land to sea. and this is called land breeze
(i) Eutrophication is the process by which algae develop excessively in a body of water due to an overabundance of minerals and nutrients.
(ii) The bacterial breakdown of the algae may result in oxygen depletion of the water body.
(iii) An "algal bloom" is one example.
(iv) The release of nitrate or phosphate-containing detergents, fertilizers, or sewage into an aquatic system usually causes eutrophication.
Question 22.
What is soil erosion? How is it prevented? Question 23.
How is soil formed? Question 24.
Write the role of lichen, moss, fungi in soil formation? Answers
The lichen grows on the surface of rocks. They produce chemicals that cause the rock surface to powder down and form a thin coating of soil as they grow.
Small plants, such as moss, can now grow on this surface, causing the rock to break up even more
Trees aid in binding soil particles together and preventing soil erosion.
Question 25.
What is nitrification? Question 26.
Describe water cycle? Question 27.
What is biological magnification? Question 28.
Why nitrogen is essential for us? Question 29.
What is ozone depletion?
Long answer type
Question 30.
What is meant by air pollution? Explain any two human activities that causes air pollution. Mention any three harmful effects of air pollution? Question 31.
Mention any three important roles of water essential for the life of organisms on earth’s surface? Question 32.
How is percentage of carbon dioxide maintained in the atmosphere? Mention one human activity which adds carbon dioxide in the atmosphere? Question 33.
List three human activities which would lead to an increase in the carbon dioxide content of air? Question 34.
What is the chemical formula of ozone? What essential function does this gas perform and where it is found? What are CFCs? Question 35.
Mention three ways by which atmosphere regulates the average temperature on earth? Question 36.
How are clouds formed? List any three human activities that you think would lead to air pollution and briefly explain each of them? Question 37.
Write the composition of soil. On what basis is the type of soil decided? Question 38.
In coastal areas, the wind blows from sea to land during the day. Why? Question 39.
List three human activities responsible for the pollution of water bodies? Question 40.
What is soil erosion? Writes its two causes. Which are the three methods of preventing soil erosion?
Summary
This Natural Resources Class 9 Important questions and answers is prepared keeping in mind the latest syllabus of CBSE . This has been designed in a way to improve the academic performance of the students. If you find mistakes , please do provide the feedback on the mail.
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