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

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.
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(1) Lead is one of the most serious environmental pollutants which affects
[1] Air
[2] Soil
[3] Water
[4] Noise
Answer: Soil
(2) Contamination of water with sewage is indicated by cysts of
[1] Escherichia
[2] Escherichia coli
[3] Pseudomonas
[4] Leishmania
Answer: Escherichia coli
(3) Non-Ionizing radiations with specific biological effects are
[1] Gamma rays
[2] Beta-rays
[3] UV radiations
[4] X-rays
Answer: UV radiations
(4) Carbon dioxide is called green-house gas because it is
[1] Transparent to sunlight but traps heat
[2] Transparent to heat but traps sunlight
[3] Used in green-house to increase plant growth
[4] Transparent to both sunlight and heat
Answer: Transparent to sunlight but traps heat
(5) Which one of the following pairs of gases are the major causes of "Greenhouse Effect"?
[1] CO2 and N2O
[2] CO2 and O3
[3] CO2 and CO
[4] CFCs and SO2
Answer: CO2 and N2O
(6) Trichoderma harzianum has proved a useful microorganism for:
[1] Reclamation of wastelands
[2] Bioremediation of contaminated soils
[3] Biological control of soil-borne plant pathogens
[4] Gene transfer in higher plants
Answer: Bioremediation of contaminated soils
(7) ______ are used in electrostatic precipitators.
[1] Catalysts
[2] Electrodes
[3] Absorbers
[4] Chemicals
Answer: Electrodes
(8) lf there was no CO2 in the atmosphere, the earth’s temperature would be
[1] Less than the present
[2] Same as present
[3] Higher than the present
[4] Dependent on O2 content of air
Answer: Less than the present
(9) Ultraviolet radiation from sunlight causes the reaction that produces
[1] Fluorides
[2] Ozone
[3] Carbon monoxide
[4] Sulphur dioxide
Answer: Ozone
(10) Ozone day is observed on
[1] September 16
[2] April 25
[3] January 15
[4] December 16
Answer: September 16
(11) Biological oxygen demand of ______ is the least.
[1] sewage
[2] sea water
[3] pure water
[4] polluted water
Answer: pure water
(12) Biochemical Oxygen Demand (BOD) in a river water
[1] Increases when sewage gets mixed with river water
[2] Remains unchanged when algal bloom occurs
[3] Has no relationship with concentration of oxygen in the water
[4] Gives a measure of salmonella in the water
Answer: Increases when sewage gets mixed with river water
(13) The two gases making highest relative contribution to the greenhouse gases are
[1] CO2 and N2O
[2] CO2 and CH4
[3] CH4 and N2O
[4] CFC5 and N2O
Answer: CO2 and CH4
(14) DDT is a
[1] Green house gas
[2] Non-degradable pollutant
[3] Degradable pollutant
[4] None of these
Answer: Non-degradable pollutant
(15) Ozone depletion in the stratosphere will cause
[1] Increased incidence of skin cancer
[2] Forest tires
[3] Global warming
[4] none of these
Answer: Increased incidence of skin cancer

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