MCQ Questions for Class 12 Biology: Ch 16 Environmental Issues
1. High value of BOD (Biochemical Oxygen Demand) indicates that :
(a) Water is highly polluted
(b) Water is less polluted
(c) Consumption of organic matter in the water is higher by the microbes
(d) Water is pure
► (a) Water is highly polluted
2. Photochemical smog is caused by a light-mediated reaction between
(a) SO2 and O3
(b) SO2 and unburnt hydrocarbons
(c) NO2 and unsaturated hydrocarbons
(d) NO2 and O3
► (c) NO2 and unsaturated hydrocarbons
3. Which of the following elements is responsible for Minamata disease?
(a) Pb
(b) Cd
(c) Fe
(d) Hg
► (d) Hg
(a) Pb
(b) Cd
(c) Fe
(d) Hg
► (d) Hg
4. Which of the following is an effect of waste accumulation?
(a) Urbanisation
(b) Over population
(c) Health problems
(d) Industrialisation
► (c) Health problems
5. The process of restoring a forest which once existed but was removed at some point of time in the past is called
(a) Tree plantation
(b) Afforestation
(c) Deforestation
(d) Reforestation
► (d) Reforestation
6. Large-scale disposal of solid waste in low areas of the ground and then covering it with earth is called
(a) Deep well injection
(b) Landfill
(c) Pyrolysis
(d) Incineration
► (b) Landfill
7. A river with an inflow of domestic sewage rich in organic waste may result in
(a) drying of the river very soon due to algal bloom.
(b) increased population of aquatic food web organisms.
(c) an increased production of fish due to biodegradable nutrients.
(d) death of fish due to lack of oxygen.
► (d) death of fish due to lack of oxygen.
8. A gas produced by paddy fields and involved in global warming is
(a) Carbon dioxide
(b) Methane
(c) Sulphur dioxide gas
(d) Chlorine
► (b) Methane
9. According to Central Pollution Control Board (CPCB), which particulate size in diameter (in micrometers) of the air pollutants is responsible for greatest harm to human health?
(a) 5.2 - 2.5
(b) 2.5 or less
(c) 1.5 or less
(d) 1.0 or less
► (b) 2.5 or less
10. Joint Forest Management Concept was introduced in India during
(a) 1960s
(b) 1970s
(c) 1980s
(d) 1990s
► (c) 1980s
11. Chlorofluorocarbons are responsible for
(a) Thermal inversion
(b) Acid rain
(c) Ozone layer depletion
(d) Global warming
► (c) Ozone layer depletion
12. What is the 3R approach?
(a) Reduce, Remove and Replenish
(b) Reduce, Remove and Reuse
(c) Reuse, Replenish and Remove
(d) Reduce, Reuse and Recycle
► (d) Reduce, Reuse and Recycle
13. Which of the following correctly represents the stages in solid waste management?
(a) Segregation – Collection – Transportation – Dumping
(b) Transportation – Collection – Segregation – Dumping
(c) Collection – Segregation – Transportation – Dumping
(d) Collection – Segregation – Dumping – Transportation
► (c) Collection – Segregation – Transportation – Dumping
14. The ozone hole causes
(a) Reduction in the rate of photosynthesis
(b) Global warming
(c) More ultraviolet rays coming to the Earth
(d) Thermal pollution
► (c) More ultraviolet rays coming to the Earth
15. Ozone depletion shall cause higher incidence of
(a) Decreased immunity only.
(b) Skin cancer only
(c) Skin cancer, Cataract and decreased immunity.
(d) Cataract only
► (c) Skin cancer, Cataract and decreased immunity.
16. Which of the following does not cause desertification?
(a) Deforestation
(b) Restricted grazing
(c) Poor irrigation practices
(d) Over cultivation
► (b) Restricted grazing
17. In normal adults, the enzyme which catalyses conversion of MHb into Hb is:
(a) MHb protease
(b) MHb oxidase
(c) MHb lipase
(d) MHb reductase
► (d) MHb reductase
18. All are biofuels except:
(a) ethanol
(b) biopetrol
(c) biodiesel
(d) marsh gas
► (b) biopetrol
19. The term biomagnification refers to the
(a) Growth of organisms due to food consumption
(b) Blowing up of environmental issues by man
(c) Increase in the concentration of non-degradable pollutants as they pass through the food chain
(d) Increase in population size
► (d) Increase in the concentration of non-degradable pollutants as they pass through the food chain
20. In a polluted environment, the concentration of pollutant would be maximum in
(a) Primary consumers
(b) Tertiary consumers
(c) Producers
(d) Secondary consumers
► (b) Tertiary consumers
21. Which of the following will be able to cope with greenhouse effect?
(a) Hibernators
(b) Homeotherms
(c) Poikilotherms
(d) Stenotherms
► (b) Homeotherms
22. Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers
(a) Nitrous oxide
(b) Ozone
(c) Ammonia
(d) Methane
► (b) Ozone
23. Substances which can be broken down into non-poisonous substances by the action of microorganisms are said to be
(a) Non-degradable
(b) Non-biodegradable
(c) Non-decomposable
(d) Biodegradable
► (d) Biodegradable
24. A common indicator organism of water pollution is
(a) Lemna paucicostata
(b) Escherichia coli
(c) Entamoeba histolytica
(d) Eichhornia crassipes
► (b) Escherichia coli
25. Oil spills prevent oxygenation of water so they are :
(a) Biological pollutants
(b) Chemical pollutants
(c) Physical pollutants
(d) None of the above
► (c) Physical pollutants
26. Eutrophication of water bodies leading to killing of fishes is mainly due to non-availability of :
(a) Light
(b) Essential minerals
(c) Oxygen
(d) Food
► (c) Oxygen
► (c) Oxygen
27. The UN conference of Parties on climate change in the year 2012 was held at:
(a) Doha
(b) Lima
(c) Warsaw
(d) Durban
► (a) Doha
28. That species which is found in highest concentration within a polluted water reservoir is called :
(a) Index species
(b) Climax species
(c) Fugitive species
(d) Pioneer species
► (a) Index species
29. The neurotoxic form of Mercury which can be directly absorbed by fishes :
(a) Benzomercury
(b) Methyl mercury
(c) Acetyl mercury
(d) Ethyl mercury
► (b) Methyl mercury
30. How should the hazardous waste be disposed of?
(a) It should be disposed of after proper treatment.
(b) It should be thrown in the sea.
(c) It should be burnt.
(d) It should be disposed of randomly.
► (a) It should be disposed of after proper treatment.