Environmental Issues: NEET MCQ Questions [100+ Solved]

Here you will find NEET MCQ questions on the Class 12 Biology Chapter “Environmental Issues” based on the NCERT textbook. Solve the below free NEET mock test for a better understanding of the various topics. 100+ important MCQs (multiple choice questions) are given in this NEET question bank.

“Environmental Issues” is the 16th chapter in the unit “Ecology” of class XII or class 12th Biology NCERT. Do note that NEET (which is conducted by NTA) is based on NCERT books so they are a must have. You can also download PDF of NCERT textbooks.

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An atmospheric pollutant is
(a) 0.0034%
(b) 0.034%
(c) 0.34%
(d) 3.4%

(b) 0.034%

What is the incorrect statement in the following list?
(a) Carbon monoxide is the major environmental pollutant
(b) All pollutants are not waste
(c) Nitrogen and magnesium can pollute water
(d) Lichens are affected by Sulphur

(b) All pollutants are not waste

Lichens are important in the studies on atmospheric pollution because they
(a) Can grow in a polluted atmosphere
(b) Can readily multiply in a polluted atmosphere
(c) Efficiently purify the atmosphere
(d) Are very sensitive to pollutants like sulphur dioxide

(d) Are very sensitive to pollutants like sulphur dioxide

The main pollutant in the air is
(a) CO2
(b) CO
(c) N2
(d) Sulphur

(b) CO

Aerosols are particles in air, less than
(a) 2μ
(b) 4μ
(c) 3μ
(d) 1μ

(d) 1μ

Noise pollution occurs when noise exceeds
(a) 70-75 dB
(b) 50-60 dB
(c) 80-99 dB
(d) 40-65 dB

Which pollution causes photochemical smog
(a) Soil
(b) Water
(c) Air
(d) Noise

Up to 80% of the total pollution in metropolitan areas comes from
(a) Pesticide
(b) Radioactivity
(c) Loudspeaker
(d) Automobiles

(d) Automobiles

Which of the following does not result in pollution?
(a) Thermal power project
(b) Steel power plant
(c) Automobiles
(d) Hydroelectric project

(d) Hydroelectric project

Which of the following pollutant is the most harmful?
(a) NO2
(b) CO2
(c) SO2
(d) CO

Factor contributing to the greenhouse effect
(a) green trees in the house
(b) grasslands
(c) global warming
(d) greenery in the country

What does deforestation cause?
(a) soil erosion
(b) loss of biodiversity
(c) disturbance in the hydrological cycle
(d) All of the above

(d) All of the above

What is reduced by eutrophication?
(a) dissolved CO2
(b) dissolved O2
(c) dissolved nutrients
(d) None of the above

(b) dissolved O2

Taj Mahal may be destroyed due to?
(a) Flood in Yamuna river
(b) Decomposition of marble as a result of high temperature
(c) Air pollutants released from oil refinery of Mathura
(d) All of the above

Carbon monoxide (CO) is harmful to humans because?
(a) It forms carbolic acid
(b) It generates excess CO2
(c) It is carcinogenic
(d) It competes with O2 for haemoglobin

(d) It competes with O2 for haemoglobin

Acid rain is caused by an increase in the concentration of?
(a) SO2 and NO2
(b) CO and CO2
(c) CO and SO3
(d) O3 and dust

(a) SO2 and NO2

What undesirable changes do pollution cause in the following characteristics of air, water, land or soil?
(a) Physical
(b) Chemical
(c) Biological
(d) All of these

(d) All of these

Scrubbers are primarily used to remove the following gases from the exhaust after spraying water/ lime
(a) CO2
(b) SO2
(c) O2 & N2
(d) CO & CO2

(b) SO2

Volcanoes are _ source of pollution
(a) artificial
(b) natural
(c) Both (a) and (b)
(d) man-made

(b) natural

Fluorosis is carried by
(a) CO2
(b) Chlorine
(c) Nitrogen
(d) Water

(d) Water

Cause of gastrointestinal disturbance is
(a) Chromium
(b) Cadmium
(c) Sodium
(d) Selenium

(d) Selenium

The full form of B.O.D. is
(a) Biological organism death
(b) Biotic oxygen demand
(c) Biochemical oxygen demand
(d) Biological organisation day

B.O.D. test of biological oxygen demand is used to measure
(a) Air pollution
(b) Water pollution
(c) Noise pollution
(d) Soil pollution

(b) Water pollution

Oxygen plays a significant role in a BOD test as it
(a) Destroy inorganic matter
(b) Destroy pollution
(c) Destroy waste organic matter
(d) None of these

The environment is heated by
(a) visible light
(b) UV rays
(c) infrared waves
(d) radiowaves

As a result of global warming, sea levels will
(a) increase
(b) decrease
(c) remain the same
(d) None of these

(a) increase

Identify the statement that describes the eco-friendly disposal of municipal solid waste
(a) It should be burnt to completion
(b) It should be dumped in an open wasteland
(c) It should be dumped in sanitary landfills
(d) It should be sorted out into bio-degradable, non- bio-degradable and recyclable wastes and treated separately

(d) It should be sorted out into bio-degradable, non- bio-degradable and recyclable wastes and treated separately

The troposphere reflects what percentage of solar radiation into outer space?
(a) 10%
(b) 17%
(c) 34%
(d) 90%

Organic substances found in the biosphere necessarily contain
(a) Silica
(b) Carbon
(c) Oxygen
(d) Nitrogen

(b) Carbon

The region that lies above the troposphere up to 50 km in distance is called
(a) Mesosphere
(b) Stratosphere
(c) Troposphere
(d) Thermosphere

(b) Stratosphere

If CO2 in the earth’s atmosphere disappears, the earth’s surface would
(a) Increase
(b) Decrease
(c) Depend on oxygen concentration
(d) Remain the same

(b) Decrease

Which of these has the least greenhouse effect?
(a) Carbon dioxide
(b) Nitrogen gas
(c) Water vapours
(d) Ozone

(b) Nitrogen gas

Gas produced by paddy fields and involved in global warming is
(a) Chlorine
(b) Methane
(c) CO2
(d) H2S

(b) Methane

Greenhouse gases include
(a) CO2, CFC, CH4 & NO2
(b) CO2, O2, N2, NO2 & NH3
(c) CH4, N2, CO2 & NH3
(d) CFC, CO2, NH3 & N2

(a) CO2, CFC, CH4 & NO2

Checking of re-radiating heat by atmospheric dust, O3, CO2 and water vapour is
(a) Ozone layer effect
(b) Solar effect
(c) Radioactive effect
(d) Greenhouse effect

(d) Greenhouse effect

Ozone is thicker at
(a) equator
(b) poles
(c) mountains
(d) sea

(b) poles

Among the following, which is not a greenhouse gas?
(a) O2
(b) CO2
(c) N2O
(d) CH4

(a) O2

The Montreal Protocol was called to examine the emission of
(a) e-wastes
(b) UV radiation
(c) CFCs
(d) All of these

Which of the following is not considered an atmosphere pollutant?
(a) CO2
(b) SO2
(c) Hydrogen
(d) CO

(a) CO2

The major aerosol pollutant in jet emissions is
(a) Sulphur dioxide
(b) Carbon monoxide
(c) Methane
(d) Fluorocarbon

(d) Fluorocarbon

Which of the following is not correctly matched?
(a) Formaldehyde – carcinogenic
(b) Sulphur dioxide – respiratory problems
(c) Nitrogen oxide – brown air
(d) Mean annual temperature – 25° C

(d) Mean annual temperature – 25° C

The control of gaseous pollutants can be achieved by
(a) Arrestors
(b) Electrostatic precipitators
(c) Pyrolysis
(d) Adsorption

(d) Adsorption

Which one of the following acts as a secondary pollutant?
(a) Br2
(b) Cl2
(c) NO2
(d) HNO3

(d) HNO3

Identify the most efficient device to eliminate particulate matter from industrial emissions?
(a) Cyclonic separators
(b) Trajectory separators
(c) Incineration
(d) Electrostatic precipitator

(d) Electrostatic precipitator

Cleaning Environment with biological options such as microbes and plants are called
(a) Bioremediation
(b) Biotechnology
(c) Biowarfare
(d) Incineration

(a) Bioremediation

Given a half-reduction in forest cover, what is most likely to happen on a long term basis?
(a) Tribals living in these areas will starve to death.
(b) Cattle in these and adjoining areas will die due to lack of fodder.
(c) Large areas will become deserts.
(d) Crop breeding programmes will suffer due to the reduced availability of a variety of germplasm.

Extensive planting of trees is known as
(a) afforestation
(b) agroforestry
(c) deforestation
(d) social forestry

(a) afforestation

Appropriate measures to reduce overall greenhouse gas emissions are the commitments of the
(a) Montreal Protocol
(b) Environment Act
(c) Kyoto Protocol
(d) Earth Summit

In India, jhum cultivation is practised in
(a) North-East states
(b) South–West coast
(c) South-East coast
(d) Gangetic plain

(a) North-East states

Ozone layer is formed in which zone of the atmosphere
(a) Mesosphere
(b) Stratosphere
(c) Troposphere
(d) Ionosphere

(b) Stratosphere

What gas in the atmosphere holds up ultraviolet rays?
(a) O2
(b) O3
(c) N2
(d) CH4

(b) O3

Why is ozone concentration less over the north and south poles?
(a) CFCs accumulate only in an area where the air is cold
(b) CFC use is highest in these areas
(c) CFCs stick to frozen water vapour and can act as catalysts
(d) UV rays are stronger in the atmosphere

Polluted water is commonly represented by the following organisms:
(a) E. coli
(b) P. typhi
(c) Vibrio
(d) Entamoeba

(a) E. coli

Eggshell thinning in birds is caused by DDT because it inhibits
(a) calmodulin
(b) calcium ATPase
(c) magnesium ATPase
(d) carbonic anhydrase

(b) calcium ATPase

DDT is banned nowadays because it is
(a) Very costly
(b) Note available
(c) Inflammable
(d) Not degraded easily

(d) Not degraded easily

Lakes A and B are identical in every way except that lake A has a higher temperature. Which statement is true?
(a) A has a higher rate of Oxygen dissolution
(b) B has a higher rate of Oxygen dissolution
(c) Oxygen dissolution of both is the same
(d) Both have the same BOD

(b) B has a higher rate of Oxygen dissolution

Which pollutant is non-degradable?
(a) Smoke
(b) Polythene
(c) Copper scraps
(d) Iron scraps

(b) Polythene

Fluoride pollution causes chlorosis or necrosis of
(a) Leaf margin and tip
(b) Stem
(c) All membrane systems
(d) Nucleus

(a) Leaf margin and tip

Radioactive pollutants have the following adverse effects:
(a) Gene mutation
(b) Hepatitis
(c) Polio
(d) T.B.

(a) Gene mutation

Non-biodegradable waste includes:
(a) DDT
(b) leather
(c) wool
(d) cotton

(a) DDT

Ozone hole refers to
(a) increased concentration of ozone
(b) reduction in thickness of ozone layer in the stratosphere
(c) reduction in the thickness of the ozone layer in the atmosphere
(d) hole in the ozone layer.

(b) reduction in thickness of ozone layer in the stratosphere

The best way to stop water pollution is by
(a) Treating effluents to remove injurious chemicals
(b) Rearing more fishes
(c) Cultivating useful water plants
(d) Spraying with DDT

(a) Treating effluents to remove injurious chemicals

The amount of fresh water on earth frozen as polar or glacial ice is
(a) 0.5 %
(b) 0.02 %
(c) 0.01%
(d) 1.97 %

(d) 1.97 %

DDT is a
(a) Non-biodegradable pollutant
(b) Biodegradable pollutant
(c) Antibiotics
(d) None of the above

(a) Non-biodegradable pollutant

Spraying DDT on crops causes pollution of
(a) Air only
(b) Air and soil only
(c) Air, soil and water
(d) Air and water only

Thermal pollution of water bodies occurs as a result of
(a) Discharge of heat (hot water) from power plants
(b) Discharge of chemicals from industries
(c) Discharge of waste from mining
(d) Discharges of agricultural runoff

(a) Discharge of heat (hot water) from power plants

Excessive fertilizer discharge into water bodies results in
(a) Growth of fish
(b) Death of hydrophytes
(c) Eutrophication
(d) Silt

When a huge amount of sewage is dumped into a river, the BOD will
(a) Increase
(b) Remain unchanged
(c) Slightly decrease
(d) Decrease

(a) Increase

Fish die from sewage because
(a) Of its bad smell
(b) It replaces food material of fishes
(c) It increases oxygen competition among fishes
(d) CO2 is mixed in large amounts in water

Which of the following is most likely to have the highest level of D.D.T. depositions in its body?
(a) Eel
(b) Crab
(c) Seagull
(d) Phytoplankton

The presence of frequent water blooms in a lake indicates
(a) Nutrient deficiency
(b) Oxygen deficiency
(c) Excessive nutrient availability
(d) Absence of herbivores in the lake

(b) Oxygen deficiency

Carbon dioxide is known as a greenhouse gas because it is
(a) Used in green-house to increase plant growth
(b) Transparent to heat but traps sunlight
(c) Transparent to sunlight but traps heat
(d) Transparent to both sunlight and heat

By how much has the mean global temperature increased in the 20th century
(a) 0.2%
(b) 0.4%
(c) 0.6%
(d) 0.8%

Deforestation results in
(a) Increased sunlight
(b) Increased grazing area
(c) Weed control
(d) Soil erosion

(d) Soil erosion

By removing the forest cover, which constituent of the atmosphere is likely to change?
(a) O2 level is increased
(b) CO2 level is increased
(c) O2 level significantly increases
(d) CO2 level is significantly decreased

(b) CO2 level is increased

Which of the following is not used to disinfect drinking water?
(a) Chlorine
(b) Ozone
(c) Chloramine
(d) Phenyl

(d) Phenyl

Determine which pair is correctly matched
(a) Basal Convention – Biodiversity Conservation
(b) Kyoto Protocol – Climatic change
(c) Montreal Protocol – Global warming
(d) Ramsar – Groundwater Convention pollution

(b) Kyoto Protocol – Climatic change

Which pair of the following is mismatched?
(a) Fossil fuel burning – release of CO2
(b) Nuclear power – radioactive wastes
(c) Solar energy – the greenhouse effect
(d) Biomass burning – release of CO2

What is the BOD limit prescribed by the Central Pollution Control Board for the discharge of industrial and municipal wastewater into natural surface water?
(a) < 10 ppm
(b) < 100 ppm
(c) < 30 ppm
(d) < 3.0 ppm

(a) < 10 ppm

Pollution from photochemical smog does not contain
(a) Nitrogen dioxide
(b) Carbon dioxide
(c) PAN (peroxyacetyl nitrate)
(d) Ozone

(b) Carbon dioxide

The Montreal protocol, which calls for action to protect the ozone layer from human activities, was adopted in
(a) 1987
(b) 1988
(c) 1985
(d) 1986

(a) 1987

In which one of the following the BOD (Biochemical Oxygen Demand) of sewage (s), distillery effluent (DE), paper mill effluent (PE) and sugar mill effluent (SE) has been arranged in ascending order?
(a) SE < PE < S < DE
(b) PE < S < SE < DE
(c) S < DE < PE < SE
(d) SE < S < PE < DE.

(b) PE < S < SE < DE

Electrostatic precipitators are installed in coal-fired power plants to control emissions of?
(a) NO×
(b) SPM
(c) CO
(d) SO2

(b) SPM

Bioindicators of water pollution cannot include which of the following?
(a) Blood-worms
(b) Stoneflies
(c) Sewage fungus
(d) Sludge-worms.

(b) Stoneflies

A global agreement on specific control strategies to reduce ozone-depleting substances has been adopted by?
(a) The Montreal Protocol
(b) The Kyoto Protocol
(c) The Vienna Convention
(d) Rio de Janeiro Conference

(a) The Montreal Protocol

What gas caused the Bhopal gas disaster and when did it occur?
(a) 1986/Methyl isocyanate
(b) 1984/Methyl isocyanate
(c) 1985/CO
(d) 1985/Ethyl isocyanate

(b) 1984/Methyl isocyanate

Which act was enacted in 1986?
(a) The Insecticide Act
(b) The Water (Prevention and Control of Pollution) Act
(c) The Noise (Prevention and Control of Pollution) Act
(d) The Environment (Protection) Act

(d) The Environment (Protection) Act

What effects will a lake with high levels of artificial eutrophication have?
(a) high nutrient levels, large phytoplankton populations, and low oxygen levels at depth.
(b) high levels of nutrients, low phytoplankton levels, high oxygen levels in surface waters.
(c) low nutrient levels, large phytoplankton populations, and low oxygen levels at depth.
(d) low nutrient levels, low phytoplankton populations, and high oxygen levels at depth.

(a) high nutrient levels, large phytoplankton populations, and low oxygen levels at depth.

Which of the following strategy is not a correct approach to reduce global warming?
(a) Reducing the greenhouse gas emission by limiting the use of fossil fuels
(b) Increase the vegetation cover particularly the forest for photosynthetic utilization of CO2
(c) Minimizing the use of nitrogen fertilizers in agriculture for reducing N2O emissions.
(d) Increasing the use of air conditioners, refrigeration units and production of plastic foams and propellants in aerosol spray cans

(d) Increasing the use of air conditioners, refrigeration units and production of plastic foams and propellants in aerosol spray cans

Greenhouse gas concentrations are very high today because of?
(a) Use of refrigerator
(b) Increased combustion of oils and coal
(b) Deforestation
(d) All of the above

(d) All of the above

Biochemical Oxygen Demand (BOD) of river water
(a) has no relationship with the concentration of oxygen in the water.
(b) gives a measure of Salmonella in the water.
(c) increases when sewage gets mixed with river water.
(d) remains unchanged when algal bloom occurs.

What plant species would you choose for the production of bioethanol?
(a) Zea mays
(b) Pongamia
(c) Jatropha
(d) Brassica

As a biofuel substitute for fossil fuels, which of the following is being tried in India?
(a) Jatropha
(b) Azadirachta
(c) Musa
(d) Aegilops

(a) Jatropha

Which one of the following is the correct percentage of the two (out of the total of 4) greenhouse gases that contribute to total global warming?
(a) CFCs 14%, Methane 20%
(b) CO2, 40%, CFCs 30%
(c) N2O 6%, CO2 86%
(d) Methane 20%, N2O 18%

(a) CFCs 14%, Methane 20%

Where was the World Summit on Sustainable Development (2002) held?
(a) Brazil
(b) Sweden
(c) Argentina
(d) South Africa

(d) South Africa

Which of the following is a renewable exhaustible natural resource?
(a) coal
(b) petroleum
(c) minerals
(d) forest

(d) forest

dB is a standard abbreviation used for the quantitative expression of?
(a) the density of bacteria in a medium
(b) a particular pollutant
(c) the dominant Bacillus in a culture
(d) a certain pesticide

(b) a particular pollutant

What are the two gases contributing most to greenhouse gases?
(a) CO2 and CH4
(b) CH4 and N2O
(c) CFC and N2O
(d) CO2 and N2O

(a) CO2 and CH4

What are stirred tank bioreactors designed for?
(a) addition of preservatives to the product
(b) purification of the product
(c) ensuring anaerobic conditions in the culture vessel
(d) availability of oxygen throughout the process

(d) availability of oxygen throughout the process

What is the correct expanded form of the following acronyms?
(a) IPCC = International Panel for Climate Change
(b) UNEP = United Nations Environmental Policy
(c) EPA= Environmental Pollution Agency
(d) IUCN = International Union for Conservation of Nature and Natural Resources

(d) IUCN = International Union for Conservation of Nature and Natural Resources

Which of the following statements is incorrect about the Bhopal tragedy?
(a) Methyl isocyanate gas leakage took place
(b) Thousands of human beings died
(c) Radioactive fall out engulfed Bhopal
(d) It took place on the night of December 2/3 1984.

Where is “good ozone” found?
(a) mesosphere
(b) troposphere
(c) stratosphere
(d) ionosphere

What is the purpose of measuring the Biochemical Oxygen Demand (BOD)?
(a) estimating the amount of organic matter in sewage water.
(b) working out the efficiency of oil-driven automobile engines.
(c) measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale.
(d) working out the efficiency of RBCs about their capacity to carry oxygen.

(a) estimating the amount of organic matter in sewage water.

What is the goal of the Montreal Protocol?
(a) Biodiversity conservation
(b) Control of water pollution
(c) Control of CO2 emission
(d) Reduction of ozone-depleting substances

(d) Reduction of ozone-depleting substances

DDT residues are rapidly absorbed by the food chain and cause biomagnification because it is
(a) moderately toxic
(b) non-toxic to aquatic animals
(c) water-soluble
(d) lipo soluble

(d) lipo soluble

Chipko movement was launched to protect?
(a) forests
(b) livestock
(c) wetlands
(d) grasslands

(a) forests

Which of the following pairs of gases is the major cause of the greenhouse effect?
(a) CO2 and O3
(b) CO2 and CO
(c) CFC and SO2
(d) CO2 and N2O

(d) CO2 and N2O

Sewage treatment is primarily an
(a) physical process
(b) mechanical process
(c) chemical process
(d) biological process

(d) biological process

Which of the following is primarily produced by the activity of anaerobic bacteria on sewage?
(a) Laughing gas
(b) Propane
(c) Mustard gas
(d) Marsh gas

(d) Marsh gas

When did the Air Prevention and Control of Pollution Act come into effect?
(a) 1981
(b) 1985
(c) 1990
(d) 1975

(a) 1981

Relative Biological Effectiveness (RBE) refers to the damage caused by?
(a) Low temperature
(b) High temperature
(c) Encephalitis
(d) Radiation

(d) Radiation

Escherichia coli is used as an indicator organism to determine whether water is polluted with
(a) pollen of aquatic plants
(b) heavy metals
(c) faecal matter
(d) industrial effluents

Which of the following is a pollution-related occupational health hazard?
(a) Pneumoconiosis
(b) Asthma
(c) Fluorosis
(d) Silicosis

(d) Silicosis

What is the use of lichens in cases of pollution?
(a) They treat the polluted water
(b) They act as bioindicators of pollution
(c) They promote pollution
(d) Lichens are not related to pollution

(b) They act as bioindicators of pollution

How does carbon monoxide prevent the transport of oxygen into the body tissues?
(a) By destroying the haemoglobin
(b) By forming a stable compound with haemoglobin
(c) By obstructing the reaction of oxygen with haemoglobin
(d) By changing oxygen into carbon dioxide.

(b) By forming a stable compound with haemoglobin

Which of the following organisms is used as an indicator of water quality?
(a) Chlorella
(b) Azospirillum
(c) Escherichia
(d) Biggiatoa

How can global warming be controlled?
(a) Reducing deforestation, increasing the use of fossil fuel.
(b) Increasing deforestation, slowing down the growth of the human population.
(c) Increasing deforestation, reducing the efficiency of energy usage.
(d) Reducing deforestation, cutting down use of fossil fuel.

(d) Reducing deforestation, cutting down use of fossil fuel.

Kyoto Protocol’s second commitment period was adopted in
(a) Cancun
(b) Durban
(c) Bali
(d) Doha

(d) Doha

What does the greenhouse effect refer to?
(a) cooling of the earth
(b) trapping of UV rays
(c) production of cereals
(d) warming of the earth

(d) warming of the earth

As far as the harmful effects of particulate matter of a size of 2.5 micrometers or less are concerned, which of the following is incorrect?
(a) It can be inhaled into the lungs
(b) It can cause respiratory problems
(c) It can directly enter into our circulatory system
(d) It can cause inflammation and damage to the lungs