14. Natural Resources

Class 9 Chapter 14. Natural Resources Choose the correct answers :

Q1. The outer crust of the Earth is called :

(A) Lithosphere

(B) Hydrosphere

(C) Atmosphere

(D) Biosphere

Ans : (A) Lithosphere .

Q2. What would happen, if all the oxygen present in the environment 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 .

Ans : (B) It will become poisonous and kill living forms

Q3. 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

Ans : (C) ozone and oxygen .

Q4. 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

Ans : (B) the number of water bodies in an area

Q5. 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

Ans :  (B) elemental form of oxygen

Q6. Among the given options, which one is not correct for the use of large amount of fertilizers and pesticides ?

(A) They are eco-friendly

(B) They turn the fields barren after some time

(C) They adversary affect the useful component from the soil

(D) They destroy the soil fertility

Ans : (A) They are eco-friendly .

Q7. 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

Ans : (C) increase during day and decrease during night

Q8. 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

Ans : (D) photosynthesis .

Q9. 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

Ans :  (C) A change in pressure of the water bodies

Q10. Which of the following is not a green house gas ?

(A) Methane

(B) Carbon dioxide

(C) Carbon monoxide

(D) Ammonia

Ans : (D) Ammonia .

Q11. Which step is not involved in the carbon-cycle ?

(A) Photosynthesis

(B) Transpiration

(C) Respiration

(D) Burning of fossil fuels

Ans : (B) Transpiration .

Q12. ‘‘ 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 .

Ans : (B) thinning of the ozone layer

Q13. Greenhouse gases are :

(A) Carbon dioxide

(B) Methane

(C) Chlorofluorocarbon

(D) All of these above

Ans :   (A) Carbon dioxide

Q14. Major source of mineral in soil is the

(A) parent rock from which soil is formed .

(B) Plants

(C) animals

(D) bacteria

Ans : (A) parent rock from which soil is formed .

Q15. Biotic component of biosphere is not constituted by

(A) producers

(B) consumers

(C) decomposer

(D) air

Ans : (D) air

Q16. The outermost layer of our Earth is called :

(A) Crust

(B) Soil

(C) Wind

(D) Water

Ans : (A) Crust .

Q17. Oxygen is harmful for

(A) ferns

(B) nitrogen fixing bacteria

(C) chara

(D) mango tree

Ans : (B) nitrogen fixing bacteria

[Even the process of nitrogen-fixing by bacteria does not take place in the presence of oxygen .]

Q18. Total earth’s surface covered by water is :

(A) 75%

(B) 60%

(C) 85%

(D) 50%

Ans : (A) 75%

[Water covers 75% of the earth’s surface]

Q19. Oxygen is returned to the atmosphere mainly by

(A)  burning  of fossil fuel

(B) respiration

(C) photosynthesis

(D) fungi

Ans : (C) photosynthesis

[Oxygen is returned to he atmosphere in only one major process, that is , photosynthesis .]

Q20. The air, the water and the soil form the non-living or abiotic component of the  .

(A) Lithosphere

(B) Hydrosphere

(C) Atmosphere

(D) Biosphere

Ans : (D) Biosphere

Q21. Growth of Lichens on barren rocks is followed by the growth of –

(A) moss

(B) ferns

(C) gymnosperms

(D) algae

Ans :  (A) moss

Q22. Soil erosion can be prevented by –

(A) raising forests

(B) deforestation

(C) excessive use of fertilizer

(D) overgrazing by animals

Ans :  (A) raising forests .

Q23.  is a very abundant element on our Earth .

(A) Oxygen

(B) Nitrogen

(C) Carbon-dioxide .

(D) Ozone .

Ans : (A) Oxygen .

Q24. 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 .

Ans : (C) excessive use of man-made compounds containing both fluorine and Chlorine .

Q25. The life –supporting zone of earth is :

(A) Biosphere

(B) Lithosphere

(C) Hydrosphere

(D) Atmosphere

Ans : (A) Biosphere

Q26. Top-soil contains the following

(i) Humus and living organisms only

(ii) Humus and soil particles only

(iii) Humus , live organisms and plants

(iv) Humus , living organisms and soil particles

(A) (i) and (iv)

(B) (i) and (ii)

(C) (ii) and (iii)

(D) (iii) and (iv)

Ans : (A) (i) and (iv) .

Q27. 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 .

Ans : (B) unburnt carbon particles or hydrocarbons suspended in air .

Q28. Marked temperature changes in aquatic environment can affect :

(i) breeding of animals

(ii) more growth of aquatic plants

(iii) process of digestion in animals

(iv) availability of nutrients .

(A)  (i) , (iii) and (iv)

(B) (i) , (ii) and (iii)

(C) (ii) , (iii) and (iv)

(D) (i) , (ii) and (iv)

Ans : (A)  (i) , (iii) and (iv)

Q29. 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

Ans : (D) re- radiated by land and water .

Q30. One of the following factors does not lead to soil formation in nature .

(A) the sun

(B) water

(C) wind

(D) polythene bags

Ans :  (D) polythene bags

Q31. 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 .

Ans : (A) a biological process of nitrogen fixing bacteria present in soil .

Q32. 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

Ans : (D) photosynthesis

Q33. 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

Ans : (D) all of the above .

Q34. Biotic component of biosphere is not constituted by :

(A) producers

(B) consumers

(C) decomposer

(D) air

Ans : (D) air

Q35. Soil erosion can be prevented by

(A) raising forests

(B) deforestation

(C) excessive use of fertilizer

(D) overgrazing by animals

Ans : (A) raising forests

Q36. What happens when rain falls on soil without vegetational 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

Ans : (B) Rain water causes loss of surface soil .