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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.
76
Global agreement in specific control strategies to reduce the release of ozone depleting substances, was adopted by
[1]
The Vienna Convention
[2]
Rio de Janeiro Conference
[3]
The Montreal Protocol
[4]
The Koyoto Protocol
Answer: The Montreal Protocol
77
A chemical harmful released by Chlorofluorocarbon to ozone is
[1]
Nitrogen Peroxide
[2]
Fluorine
[3]
Chlorine
[4]
Sulphur dioxide
78
In an area where DDT had been used extensively, the population of birds declined significantly because
[1]
Cobras were feeding exclusively on birds
[2]
Many of the birds eggs laid, did not hatch
[3]
Birds stopped laying eggs
[4]
Earthworms in the area got eradicated
Answer: Many of the birds eggs laid, did not hatch
79
Greenhouse effect is caused by
[1]
Green plants
[2]
Infrared rays
[3]
UV rays
[4]
X-rays
80
Due to eutrophication______.
[1]
BOD increases
[2]
BOD decreases
[3]
algae are destroyed
[4]
water becomes less harmful
81
Minamata disease is due to pollution of
[1]
Industrial waste mercury into fishing water
[2]
Oil spill in water
[3]
Organic waste into drinking water
[4]
Arsenic into the atmosphere
Answer: Industrial waste mercury into fishing water
82
Measuring Biochemical Oxygen Demand (BOD) is a method used for
[1]
Measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale
[2]
Working out the efficiency of R.B.Cs. about their capacity to carry oxygen
[3]
Estimating the amount of organic matter in sewage water
[4]
Working out the efficiency of oil driven automobile engines
Answer: Estimating the amount of organic matter in sewage water
83
Which of the following pollutions forms Heat island?
[1]
Water
[2]
Air
[3]
Land
[4]
None of these
84
dB is a standard abbreviation used for the quantitative expression of
[1]
The dominant Bacillus in a culture
[2]
The density of bacteria in a medium
[3]
A certain pesticide
[4]
A particular pollutant
Answer: A particular pollutant
85
Among the following, a secondary pollutant is
[1]
PAN
[2]
SO2
[3]
CO
[4]
Aerosol
86
The green house gases, otherwise called radioactively active gases includes
[1]
Carbon dioxide
[2]
CH4
[3]
N2O
[4]
All of these
87
The main atmospheric layer near the surface of earth is
[1]
troposphere
[2]
mesophere
[3]
ionosphere
[4]
stratospere
88
______ is the first step of sewage treatment.
[1]
Precipitation
[2]
Chlorination
[3]
Sedimentation
[4]
Aeration
89
Identify the correctly matched pair
[1]
Basal Convention – Biodiversity Conservation
[2]
Montreal Protocol - Global warming
[3]
Kyoto protocol – Climatic change
[4]
Ramsar Convention – Ground water pollution
Answer: Kyoto protocol – Climatic change
90
CO emitted by automobiles prevents O-transport to body tissues by
[1]
Changing O2 to CO2
[2]
Destroying hemoglobin
[3]
Forming a stable compound with hemoglobin
[4]
Obstructing the reaction of O2 with hemoglobin
Answer: Forming a stable compound with hemoglobin
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