NCERT - Environmental Issues Questions and Answers of Class 12 Biology | GkSeries

Questions
91 Montreal Protocol aims at
1 Control of CO2 emission
2 Reduction of ozone depleting substances
3 Biodiversity conservation
4 Control of water pollution

Answer: Reduction of ozone depleting substances
92 Treatment of sewage involves:
1 removal of suspended particles
2 allow aerination for bacterial action
3 removal of nitrates and phosphates
4 all of these

Answer: all of these
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93 Common indicator organism of water pollution is:
1 Entamoeba histolytica
2 Escherichia coli
3 Eichhornia crassipes
4 Lemna paucicostata

Answer: Escherichia coli
94 Which rays strike on earth due to depletion of ozone layer ?
1 Ultraviolet
2 Infrared
3 Visible light
4 Microwaves

Answer: Ultraviolet
95 Main approach for conservation of water is
1 Afforestation
2 Constructing waste water treatment plnts and recycling the treated water
3 by storing rain water and recharge groun water
4 all of these

Answer: all of these
96 BOD is ______ in polluted water and ______ in potable water.
1 more, less
2 less, medium
3 medium, more
4 less, more

Answer: more, less
97 Increase in the concentration of pollutants in higher trophic levels is known as
1 Biomagnification
2 Biodegradation
3 Eutrophication
4 Recycling

Answer: Biomagnification
98 ______ is used to convert organic pollutants into water vapour and CO2.
1 Electrostatic precipitator
2 Flame combustion
3 Absorption
4 Wet-scrubber

Answer: Flame combustion
99 Which method is used to control pollutants of particulate nature ?
1 Combustion
2 Absorption
3 Electrostatic precipitators
4 Oxidation pond

Answer: Electrostatic precipitators
100 Soil pollution can be reduced by
1 biological manures
2 using biofertilizers
3 biological control
4 all of these

Answer: all of these
101 Most abundant water pollutant is
1 Industrial wastes
2 Pesticides
3 Detergents
4 Ammonia

Answer: Industrial wastes
102 Most hazardous metal pollutant of the automobile exhaust is
1 Lead
2 Mercury
3 Cadmium
4 Copper

Answer: Lead
103 Shell of egg in bird becomes thin (not properly formed) due to the pollution of pesticides. This is due to interference in the activity of :
1 Calmodulin
2 Mg ATPase
3 Ca ATPase
4 None of these

Answer: Calmodulin
104 Most harmful environmental pollutants are
1 Natural nutrients in excess
2 Human organic wastes
3 Nonbiodegradable chemicals
4 Waste animal feed

Answer: Nonbiodegradable chemicals
105 The atmosphere of big metropolitan cities is polluted most by
1 Automobile exhausts
2 Radio-active fall out
3 Household waste
4 Pesticides residue

Answer: Automobile exhausts

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