NCERT Exemplar Class 9 Science Chapter 14: Natural Resources. NCERT Exemplar Solutions for Class 9 Science Chapter 14 Natural Resources prepare students for their Class 9 exams thoroughly.
Science problems and solutions for the Class 9 pdf are provided here which are similar to the questions being asked in the previous year’s board.
Contents
NCERT Exemplar Class 9 Science Chapter 14: Natural Resources
Class 9: Science Chapter 14 solutions. Complete Class 9 Science Chapter 14 Notes.
Multiple Choice Questions
- The atmosphere of the earth is heated by radiations which are mainly
- (a) radiated by the sun
- (b) re-radiated by land
- (c) re-radiated by water
- (d) re-radiated by land and water
- If there were no atmosphere around the earth, the temperature of the earth will
- (a) increase
- (b) go on decreasing
- (c) increase during day and decrease during night
- (d) be unaffected
- What would happen, if all the oxygen present in the environmeMultiple Choice Questionsnt is converted to ozone?
- (a) We will be protected more
- (b) It will become poisonous and kill living forms
- (c) Ozone is not stable, hence it will be toxic
- (d) It will help harmful sun radiations to reach earth and damage many life forms.
- One of the following factors does not lead to soil formation in nature
- (a) the sun
- (b) water
- (c) wind
- (d) polythene bags
- 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
- The process of nitrogen-fixation by bacteria does not take place in the presence of
- (a) molecular form of hydrogen
- (b) elemental form of oxygen
- (c) water
- (d) elemental form of nitrogen
- Rainfall patterns depend on
- (a) the underground water table
- (b) the number of water bodies in an area
- (c) the density pattern of human population in an area
- (d) the prevailing season in an area
- Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?
- (a) They are eco-friendly
- (b) They turn the fields barren after some time
- (c) They adversely affect the useful component from the soil
- (d) They destroy the soil fertility
- The nitrogen molecules present in air can be converted into nitrates and nitrites by
- (a) a biological process of nitrogen fixing bacteria present in soil
- (b) a biological process of carbon fixing factor present in soil
- (c) any of the industries manufacturing nitrogenous compounds
- (d) the plants used as cereal crops in field
- One of the following processes is not a step involved in the water-cycle operating in nature
- (a) evaporation
- (b) transpiration
- (c) precipitation
- (d) photosynthesis
- The term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?
- (a) The addition of undesirable substances to water-bodies
- (b) The removal of desirable substances from water-bodies
- (c) A change in pressure of the water bodies
- (d) A change in temperature of the water bodies
- Which of the following is not a green house gas?
- (a) Methane
- (b) Carbon dioxide
- (c) Carbon monoxide
- (d) Ammonia
- Which step is not involved in the carbon-cycle?
- (a) Photosynthesis
- (b) Transpiration
- (c) Respiration
- (d) Burning of fossil fuels
- ‘Ozone-hole’ means
- (a) a large sized hole in the ozone layer
- (b) thinning of the ozone layer
- (c) small holes scattered in the ozone layer
- (d) thickening of ozone in the ozone layer
- Ozone-layer is getting depleted because of
- (a) excessive use of automobiles
- (b) excessive formation of industrial units
- (c) excessive use of man-made compounds containing both fluorine and chlorine
- (d) excessive deforestation.
- Which of the following is a recently originated problem of environment?
- (a) Ozone layer depletion
- (b) Green house effect
- (c) Global warming
- (d) All of the above
- When we breathe in air, nitrogen also goes inside along with oxygen. What is the fate of this nitrogen?
- (a) It moves along with oxygen into the cells
- (b) It comes out with the CO2 during exhalation
- (c) It is absorbed only by the nasal cells
- (d) Nitrogen concentration is already more in the cells so it is not at all absorbed.
- Top-soil contains the following
- (a) Humus and living organisms only
- (b) Humus and soil particles only
- (c) Humus, living organisms and plants
- (d) Humus, living organisms and soil particles.
- Choose the correct sequences
- (a) CO2 in atmosphere → decomposers → organic carbon in animals → organic carbon in plants
- (b) CO2 in atmosphere → organic carbon in plants → organic carbon in animals → inorganic carbon in soil
- (c) Inorganic carbonates in water → organic carbon in plants → organic carbon in animals → scavengers
- (d) Organic carbon in animals → decomposers → CO2 in atmosphere → organic carbon in plants
- Major source of mineral in soil is the
- (a) parent rock from which soil is formed
- (b) plants
- (c) animals
- (d) bacteria
- Total earth’s surface covered by water is
- (a) 75%
- (b) 60%
- (c) 85%
- (d) 50%
- Biotic component of biosphere is not constituted by
- (a) producers
- (b) consumers
- (c) decomposer
- (d) air
- An increase in carbon dioxide content in the atmosphere would not cause
- (a) more heat to be retained by the environment
- (b) increase in photosynthesis in plants
- (c) global warming
- (d) abundance of desert plants
- Oxygen is returned to the atmosphere mainly by
- (a) burning of fossil fuel
- (b) respiration
- (c) photosynthesis
- (d) fungi
- Low visibility during cold weather is due to
- (a) formation of fossil fuel
- (b) unburnt carbon particles or hydrocarbons suspended in air
- (c) lack of adequate power supply
- (d) none of these
- Growth of Lichens on barren rocks is followed by the growth of
- (a) moss
- (b) ferns
- (c) gymnosperms
- (d) algae
- Marked temperature changes in aquatic environment can affect
- (a) breeding of animals
- (b) more growth of aquatic plants
- (c) process of digestion in animals
- (d) availability of nutrients.
- Soil erosion can be prevented by
- (a) raising forests
- (b) deforestation
- (c) excessive use of fertilizer
- (d) overgrazing by animals
- What happens when rain falls on soil without vegetation cover?
- (a) Rain water percolates in soil efficiently
- (b) Rain water causes loss of surface soil
- (c) Rain water leads to fertility of the soil
- (d) Rain water does not cause any change in soil
- Oxygen is harmful for
- (a) ferns
- (b) nitrogen fixing bacteria
- (c) chara
- (d) mango tree
Short Answer Type Questions
- Rivers from land, add minerals to sea water. Discuss how?
- How can we prevent the loss of top soil?
- How is the life of organisms living in water affected when water gets polluted?
- During summer, if you go near the lake, you feel relief from the heat, why?
- In coastal area, wind current moves from the sea towards the land during day; but during night it moves from land to the sea. Discuss the reason.
- Following are a few organisms
- (a) lichen
- (b) mosses
- (c) mango tree
- (d) cactus
- Which among the above can grow on stones; and also help in formation of soil? Write the mode of their action for making soil.
- Soil formation is done by both abiotic and biotic factors. List the names of these factors by classifying them as abiotic and biotic?
- All the living organisms are basically made up of C, N, S, P, H and O. How do they enter the living forms? Discuss.
- Why does the percentage of gases like oxygen, nitrogen and carbon dioxide remain almost the same in the atmosphere?
- Why does moon have very cold and very hot temperature variations eg, from -190°C to 110°C even though it is at the same distance from the sun as the earth is?
- Why do people love to fly kites near the seashore ?
- Why does Mathura refinery pose problems to the Taj Mahal?
- Why do not lichens occur in Delhi whereas they commonly grow in Manali or Darjeeling?
- Why does water need conservation even though large oceans surround the land masses?
- There is mass mortality of fishes in a pond. What may be the reasons ?
- Lichens are called pioneer colonisers of bare rock. How can they help in formation of soil?
- “Soil is formed by water.” If you agree to this statement then give reasons
- Fertile soil has lots of humus. Why?
- Why step farming is common in hills?
- Why are root nodules useful for the plants?
Long Answer Type Questions
- How do fossil fuels cause air pollution?
- What are the causes of water pollution? Discuss how you can contribute in reducing water pollution.
- A motor car, with its glass totally closed, is parked directly under the sun. The inside temperature of the car rises very high. Explain why?
- Justify “Dust is a pollutant” ?
- Explain the role of the Sun in the formation of soil.
- Carbon dioxide is necessary for plants. Why do we consider it as a pollutant?
Answers
