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

Questions
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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