Saturday, 20 February 2021

CBSE Class 9 Science - MCQ and Online Tests - Biology - Unit 5 - Natural Resources

CBSE Class 9 Science – MCQ and Online Tests – Biology – Unit 5 – Natural Resources

Every year CBSE  schools conducts Annual Assessment exams for 6,7,8,9,11th standards. These exams are very competitive to all the students. So our website provides online tests for all the 6,7,8,9,11th standard’s subjects. These tests are also very effective and useful for those who preparing for any competitive exams like Olympiad etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE syllabus. While attempting these our students can identify the weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly.



CBSE Class 9 Science – MCQ and Online Tests – Biology – Unit 5 – Natural Resources

Question 1.
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 2.
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 3.
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 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

Answer

Answer: (c) ozone and oxygen


Question 5.
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 6.
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 7.
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 8.
The nitrogen molecules present in air can be converted into nitrates and nitrites by
(?) 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: (?) a biological process of nitrogen fixing bacteria present in soil


Question 9.
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 10.
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 11.
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 12.
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 13.
Which of the following is not a greenhouse gas?
(a) Methane
(b) Carbon dioxide
(c) Carbon monoxide
(d) Ammonia

Answer

Answer: (d) Ammonia


Question 14.
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 15.
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 16.
‘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 17.
Oxygen is harmful for
(a) ferns
(b) nitrogen fixing bacteria
(c) chara
(d) mango tree

Answer

Answer: (b) nitrogen fixing bacteria


Question 18.
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 19.
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 20.
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 21.
Top-soil contains the following
(?) 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 22.
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 23.
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 24.
Total Earth’s surface covered by water is
(a) 75%
(b) 60%
(c) 85%
(d) 50%

Answer

Answer: (a) 75%


Question 25.
Biotic component of the biosphere is not constituted by
(a) producers
(b) consumers
(c) decomposer
(d) air

Answer

Answer: (d) air


Question 26.
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 27.
Oxygen is returned to the atmosphere mainly by
(a) burning of fossil fuel
(b) respiration
(c) photosynthesis
(d) fungi

Answer

Answer: (c) photosynthesis


Question 28.
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 29.
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 30.
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


 

 

 

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