CBSE Class 12 Biology Environmental Issues MCQs Set 04

Practice CBSE Class 12 Biology Environmental Issues MCQs Set 04 provided below. The MCQ Questions for Class 12 Chapter 16 Environmental Issues Biology with answers and follow the latest CBSE/ NCERT and KVS patterns. Refer to more Chapter-wise MCQs for CBSE Class 12 Biology and also download more latest study material for all subjects

MCQ for Class 12 Biology Chapter 16 Environmental Issues

Class 12 Biology students should review the 50 questions and answers to strengthen understanding of core concepts in Chapter 16 Environmental Issues

Chapter 16 Environmental Issues MCQ Questions Class 12 Biology with Answers

Question : Lichens indicate SO2 pollution because they 
a) show association between algae and fungi
b) grow faster than others
c) are sensitive to SO2 
d) flourish in SO2 rich environment 

Answer: C

Question : Acid rains are produced by 
a) excess NO2 and SO2 from burning fossil fuels
b) excess production of NH3 by industry and coal gas
c) excess release of carbon monoxide by incomplete combustion
d) excess formation of CO2 by combustion and animal respiration 

Answer: A

 
Question : Green-house effect is warming due to 
a) infra-red rays reaching earth
b) moisture layer in atmosphere
c) increase in temperature due to increase in carbon dioxide concentration of atmosphere
d) ozone layer of atmosphere 

Answer: C

Question : Major aerosol pollutant in jet plane emission is 
a) sulphur dioxide
b) carbon monoxide
c) methane
d) chlorofluoro-carbons 

Answer: D

Question : Gas released during Bhopal tragedy was 
a) methyl isocyanate
b) potassium isothiocyanate
c) sodium isothiocyanate
d) ethyl isothiocyanate 

Answer: A

Question : Domestic waste constitutes 
a) non-biodegradable pollution
b) biodegradable pollution
c) effluents
d) air pollution 

Answer: B

Question : Which one is not a pollutant normally? 
a) Hydrocarbons
b) Carbon dioxide
c) Carbon monoxide
d) Sulphur dioxide 

Answer: B

Question : Most hazardous metal pollutant of automobile exhausts is 
a) mercury
b) cadmium
c) lead
d) copper 

Answer: C

Question : Ultraviolet radiations from sunlight cause a reaction which produces 
a) O3
b) SO2
c) CO
d) CH4 

Answer: A

Question : Drawback of DDT as pesticide is 
a) it becomes ineffective after some time
b) it is less effective than others
c) it is not easily/rapidly degraded in nature
d) its high cost 

Answer: C

Question : Highest DDT deposition shall occur in 
a) phytoplankton
b) sea gull/birds
c) crab
d) eel 

Answer: B

Question : Fish die in water bodies polluted by sewage due to 
a) pathogens
b) clogging of gills by silt
c) reduction in oxygen
d) fuel smell 

Answer: C

Question : Disease caused by eating fish found in water contaminated with industrial waste having mercury is 
a) Minamata disease
b) Blight’s disease
c) Hashimoto’s disease
d) Osteosclerosis 

Answer: A

Question : Sound becomes hazardous noise pollution at level
a) above 30 dB
b) above 80 dB
c) above 100 dB
d) above 120 dB 

Answer: B

Question : Atmosphere of big/metropolitan cities is polluted most by 
a) automobile exhausts
b) pesticide residue
c) household waste
d) radioactive fall-out 

Answer: A

Question : When huge amount of sewage is dumped into a river, its BOD will
a) increase
b) decrease
c) sharply decrease
d) remain unchanged 

Answer: A

Question : In Minamata Bay of Japan, the animals which remained free from Minamata disease, are 
a) pigs
b) rabbits
c) dogs
d) cats 

Answer: B

Question : The Taj Mahal is threatened due to the effect of 
a) oxygen
b) hydrogen
c) chlorine
d) sulphur dioxide 

Answer: D

Question : Sewage drained into water bodies kill fishes because 
a) excessive carbon dioxide is added to water
b) it gives off a bad smell
c) it removes the food eaten by fish
d) it increases competition with fishes for dissolved oxygen 

Answer: D

Question : The major contributor of green-house gases to the atmosphere is 
a) Russia
b) USA
c) Germany
d) Brazil 

Answer: B

Question : The worst environmental hazards were created by accidents in nuclear power plant and MIC gas tragedy respectively in
a) Russia in 1990 and Bhopal in 1986
b) Ukrain in 1988 and USA in 1984
c) Bhopal in 1984 and Russia in 1990
d) Ukrain in 1986 and Bhopal in 1984 

Answer: D

Question : If the forest cover is reduced to half, 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 a reduced availability of variety of germplasm 

Answer: C

Question : The most common indicator organism which represents polluted water is 
a) Escherichia coli
b) Salmonella typhi
c) Vibrio cholerae
d) Entamoeba histolytica 

Answer: A

Question : Phosphate pollution is mainly caused by
a) phosphate rock only [1997]
b) agricultural fertilizers only
c) sewage and phosphate rocks
d) sewage and agricultural fertilizers 

Answer: D

 

Question : The CO2 content by volume, in the atmospheric air is about 
a) 0.0314%
b) 0.34%
c) 3.34%
d) 4% 

Answer: A

Question : Formation of ozone hole is maximum over
a) India
b) Antarctica 
c) Europe
d) Africa 

Answer: B

Question : In coming years, skin related disorders will be more common due to 
a) air pollution
b) use of detergents
c) water pollution
d) depletion of ozone layer 

Answer: D

Question : Which one of the following organism is used as indicator of water quality ? 
a) Beggiatoa
b) Chlorella
c) Azospirillum
d) Escherichia 

Answer: D

Question : Which important green-house gas, other than methane, is being produced from the agricultural fields? 
a) Arsine
b) Sulphur dioxide
c) Ammonia
d) Nitrous oxide 

Answer: D

Question : The supersonic jets cause pollution by the thinning of 
a) CO2 layer
b) SO2 layer
c) O2 layer
d) O3 layer 

Answer: D

Question : Warm ocean surge of the peru current recurring every 5 to 8 year or so in the East Pacific of South America is widely known as 
a) Magnox
b) Gull stream
c) El Nino
d) Aye aye 

Answer: C

Question : Carbon monoxide is a pollutant because
a) it reacts with O2
b) it inhibits glycolysis
c) it reacts with haemoglobin
d) it makes nervous system inactive 

Answer: C

Question : If there was no CO2 in the earth’s atmosphere the temperature of earth’s surface would be
a) same as present 
b) less than the present
c) higher than the present
d) dependent on the amount of oxygen in the atmosphere 

Answer: B

 
Question : A sewage treatment process in which a portion of the decomposer bacteria present in the waste is recycled into the beginning of the process, is called 
a) cyclic treatment
b) primary treatment
c) activated sludge treatment
d) tertiary treatment 

Answer: C

Question : Which of the following is the use of lichens in case of pollution? 
a) Lichens are not related with pollution
b) They act as bioindicators of pollution
c) They treat the polluted water
d) They promote pollution  

Answer: B

Question : Which of the following is a secondary pollutant ? 
a) Aerosol
b) CO
c) PAN
d) CO2 

Answer: C

Question : Green-house effect refers to 
a) production of cereals
b) cooling of earth
c) trapping of UV rays
d) warming of earth 

Answer: D

Question : In 1984, Bhopal gas tragedy was caused due to the leakage of 
a) potassium isocyanate
b) sodium monoxide
c) sodium thiocyanate
d) methyl isocyanate 

Answer: D

Question : Which of the following is pollution related disorder ? 
a) Fluorosis
b) Leprosy
c) Pneumonicosis
d) Silicosis 

Answer: A

Question : Relative Biological Effectiveness [RBE] usually refers to the damages caused by 
a) low temperature
b) high temperature
c) radiation
d) pollution 

Answer: C

Question : What is the intensity of sound in normal conversation? 
a) 10-20 dB
b) 30-60 dB
c) 70-90 dB
d) 120-150 dB 

Answer: B

Question : What is BOD? 
a) The amount of O2 utilized by organisms in water
b) The amount of O2 utilized by microorganisms for decomposition
c) The total amount of O2 present in water
d) All of the above 

Answer: B

Question : Which of the following is absent in polluted water ? 
a) Hydrilla
b) Water hyacinth
c) Larva of stone fly
d) Blue-green algae 

Answer: C

Question : Fluoride pollution mainly affects 
a) teeth
b) kidney
c) brain
d) heart 

Answer: A

Question : If by radiation all nitrogenase enzymes are inactivated, then there will be no 
a) fixation of nitrogen in legumes
b) fixation of atmospheric nitrogen
c) conversion from nitrate to nitrite in legumes
d) conversion from ammonium to nitrate in soil 

Answer: A

Question : Lead concentration in blood is considered alarming if it is 
a) 20mg/100mL
b) 30mg/100mL
c) 4-6mg/100mL
d) 10mg/100mL 

Answer: B

Question : In 1984, the Bhopal gas tragedy took place because methyl isocyanate 
a) reacted with DDT
b) reacted with ammonia
c) reacted with CO2
d) reacted with water 

Answer: D

Question : Prolonged liberal irrigation of agricultural fields is likely to create the problem of 
a) acidity
b) aridity
c) metal toxicity 
d) salinity 

Answer: D

Question : Which of the following is not used for disinfection of drinking water? 
a) Phenyl
b) Chloramine
c) Chlorine
d) Ozone 

Answer: A

Question : Which one of the following pair is mismatched? 
a) Biomass burning — Release of CO2
b) Fossil fuel burning — Release of CO2
c) Nuclear power — Radioactive wastes
d) Solar energy — Green-house effect  

Answer: D

Question : Full form of B.O.D. is
a) Biological organism death
b) Biotic oxygen demand
c) Biochemical oxygen demand
d) Biological organisation day

Answer : C

 

~ MCQs Class 12 Biology (Old Chapters)
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CBSE Class 12 Biology Reproduction in Organisms MCQs Set 03
CBSE Class 12 Biology Reproduction in Organisms MCQs Set 02
CBSE Class 12 Biology Reproduction in Organisms MCQs Set 01
CBSE Class 12 Biology Environmental Issues MCQs Set 04
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CBSE Class 12 Biology Environmental Issues MCQs Set 02
CBSE Class 12 Biology Environmental Issues MCQs Set 01

Free study material for Old NCERT

MCQs for Chapter 16 Environmental Issues Biology Class 12

Students can use these MCQs for Chapter 16 Environmental Issues to quickly test their knowledge of the chapter. These multiple-choice questions have been designed as per the latest syllabus for Class 12 Biology released by CBSE. Our expert teachers suggest that you should practice daily and solving these objective questions of Chapter 16 Environmental Issues to understand the important concepts and better marks in your school tests.

Chapter 16 Environmental Issues NCERT Based Objective Questions

Our expert teachers have designed these Biology MCQs based on the official NCERT book for Class 12. We have identified all questions from the most important topics that are always asked in exams. After solving these, please compare your choices with our provided answers. For better understanding of Chapter 16 Environmental Issues, you should also refer to our NCERT solutions for Class 12 Biology created by our team.

Online Practice and Revision for Chapter 16 Environmental Issues Biology

To prepare for your exams you should also take the Class 12 Biology MCQ Test for this chapter on our website. This will help you improve your speed and accuracy and its also free for you. Regular revision of these Biology topics will make you an expert in all important chapters of your course.

Where can I access latest CBSE Class 12 Biology Environmental Issues MCQs Set 04?

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Are Assertion-Reasoning and Case-Study MCQs included in the Biology Class 12 material?

Yes, our CBSE Class 12 Biology Environmental Issues MCQs Set 04 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the CBSE paper is now competency-based.

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By solving our CBSE Class 12 Biology Environmental Issues MCQs Set 04, Class 12 students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Biology.

Do you provide answers and explanations for CBSE Class 12 Biology Environmental Issues MCQs Set 04?

Yes, Biology MCQs for Class 12 have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused CBSE exams.

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