Class 9
Subject Biology
Chapter Natural Resources
Assignment 02
Natural Resources Class 9 MCQs Questions with Answers
Question 1.
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
Answer
Answer: (d) re-radiated by land and water
Question 2.
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
Answer
Answer: (c) increase during day and decrease during night
Question 3.
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.
Answer
Answer: (b) It will become poisonous and kill living forms
Question 4.
One of the following factors does not lead to soil formation in nature
(a) the Sun
(b) water
(c) wind
(d) polythene bags
Answer
Answer: (d) polythene bags
Question 5.
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
Answer
Answer: (c) ozone and oxygen
Question 6.
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
Answer
Answer: (b) elemental form of oxygen
Question 7.
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
Answer
Answer: (b) elemental form of oxygen
Question 8.
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
Answer
Answer: (a) They are eco-friendly
Question 9.
The nitrogen molecules present in air can be converted into nitrates and nitrites by
(а) 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
Answer
Answer: (а) a biological process of nitrogen fixing bacteria present in soil
Question 10.
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
Answer
Answer: (d) photosynthesis
Question 11.
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
Answer
Answer: (c) A change in pressure of the water bodies
Question 12.
Which of the following is not a greenhouse gas?
(a) Methane
(b) Carbon dioxide
(c) Carbon monoxide
(d) Ammonia
Answer
Answer: (d) Ammonia
Question 13.
Which step is not involved in the carbon-cycle?
(o) Photosynthesis
(b) Transpiration
(c) Respiration
(d) Burning of fossil fuels
Answer
Answer: (b) Transpiration
Question 14.
‘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
Answer
Answer: (b) thinning of the ozone layer
Question 15.
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.
Answer
Answer: (c) excessive use of man-made compounds containing both fluorine and chlorine
Question 16.
Which of the following is a recently originated problem of environment?
(a) Ozone layer depletion
(b) Greenhouse effect
(c) Global warming
(d) All of the above
Answer
Answer: (d) All of the above
Question 17.
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.
Answer
Answer: (b) It comes out with the CO2 during exhalation
Question 18.
Top-soil contains the following
(а) Humus and living organisms only
(b) Humus and soil particles only
(c) Humus, living organisms and plants
(d) Humus, living organisms and soil particles.
Answer
Answer: (d) Humus, living organisms and soil particles.
Question 19.
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
Answer
Answer: (b) CO2 in atmosphere → organic carbon in plants → organic carbon in animals → inorganic carbon in soil
Question 20.
Major source of mineral in soil is the
(a) parent rock from which soil is formed
(b) plants
(c) animals
(d) bacteria
Answer
Answer: (a) parent rock from which soil is formed
Question 21.
Total Earth’s surface covered by water is
(a) 75%
(b) 60%
(c) 85%
(d) 50%
Answer
Answer: (a) 75%
Question 22.
Biotic component of the biosphere is not constituted by
(a) producers
(b) consumers
(c) decomposer
(d) air
Answer
Answer: (d) air
Question 23.
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
Answer
Answer: (d) abundance of desert plants
Question 24.
Oxygen is returned to the atmosphere mainly by
(a) burning of fossil fuel
(b) respiration
(c) photosynthesis
(d) fungi
Answer
Answer: (c) photosynthesis
Question 25.
Low visibility during cold weather is due to
(a) formation of fossil fuel
(b) unbumt carbon particles or hydrocarbons suspended in air
(c) lack of adequate power supply
(d) none of these
Answer
Answer: (b) unbumt carbon particles or hydrocarbons suspended in air
Question 26.
Growth of lichens on barren rocks is followed by the growth of
(a) moss
(b) ferns
(c) gymnosperms
(d) algae
Answer
Answer: (a) moss
Question 27.
Marked temperature changes in an aquatic environment can affect
(a) breeding of animals
(b) more growth of aquatic plants
(c) process of digestion in animals
(d) availability of nutrients.
Answer
Answer: (a) breeding of animals
Question 28.
Soil erosion can be prevented by
(a) raising forests
(b) deforestation
(c) excessive use of fertiliser
(d) overgrazing by animals
Answer
Answer: (a) raising forests
Question 29.
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
Answer
Answer: (b) Rain water causes loss of surface soil
Question 30.
Oxygen is harmful for
(a) ferns
(b) nitrogen fixing bacteria
(c) chara
(d) mango tree
Answer
Answer: (b) nitrogen fixing bacteria
