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Free Download as PDF of the detailed solutions for class 12 Biology from NCERT or CBSE text book as per exam pattern, to help you in day to day learning. We provide all important questions and answers from chapter Environmental Issues of Biology.
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
93
Common indicator organism of water pollution is:
[1]
Entamoeba histolytica
[2]
Escherichia coli
[3]
Eichhornia crassipes
[4]
Lemna paucicostata
94
Which rays strike on earth due to depletion of ozone layer ?
[1]
Ultraviolet
[2]
Infrared
[3]
Visible light
[4]
Microwaves
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
96
BOD is ______ in polluted water and ______ in potable water.
[1]
more, less
[2]
less, medium
[3]
medium, more
[4]
less, more
97
Increase in the concentration of pollutants in higher trophic levels is known as
[1]
Biomagnification
[2]
Biodegradation
[3]
Eutrophication
[4]
Recycling
98
______ is used to convert organic pollutants into water vapour and CO2.
[1]
Electrostatic precipitator
[2]
Flame combustion
[3]
Absorption
[4]
Wet-scrubber
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
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
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
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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