CBSE Class 12 Biology Environmental Issues MCQs Set C

Question: In Effluent Treatment Plants (ETPs), at which stage microorganism treatment is provided?
a) Primary
b) Secondary
c) Tertiary
d) Microorganisms are not used in ETPs
Answer: b

Question: The process of nutrient enrichment of water is called as
a) Eutrophication
b) Stratification
c) Atrophication
d) Biomagnification
Answer: a

Question: Minamata disease is caused by contamination of
a) Hg
b) Pb
c) Cd
d) As
Answer: a

Question: Algal bloom is caused by
a) Availability of excess nutrients
b) Lack of nutrients
c) Increase in non-biodegradable pollutants
d) Decreased BOD
Answer: a

Question: Thickness of ozone is measured in
a) Decibel
b) Dozen
c) Water
d) Noise
Answer: c

Question: Which of the following is not an environmental problem?
a) Wastage of water
b) Conservation of water
c) Deforestation
d) Land erosion
Answer: b

Question: What are organisms that can tolerate high degrees of pollution called as?
a) Indicator species
b) Extreme species
c) Stenohy ne species
d) Osmoconfirmers
Answer: a

Question: Increasing skin cancer and high mutation rate are the result of
a) Ozone depletion
b) Acid rain
c) CO pollution
d) CO₂ pollution
Answer: a

Question: In India, the Air (Prevention and Control of Pollution) Act came into force in 1981 but was amended in 1987 to include
a) Thermal pollution
b) Radioactive pollution
c) Noise pollution
d) Ozone pollution
Answer: c

Question: Which of the following is correct about “El Nino effect”?
a) Temperature rise leads to odd climatic changes
b) Cutting down the use of fossil fuels
c) Planting trees
d) Slowing down the growth of human population
Answer: a

Question: ___ are used in electrostatic precipitators.
a) Catalysts
b) Absorbers
c) Electrodes
d) Chemicals
Answer: c

Question: When and where was the Ozone hole discovered?
a) 1985, Antarctica
b) 1985, Arctic
c) 1987, Arctic
d) 1987, Antarctica
Answer: a

Question: Pick out the correct choice from the following
a) As BOD increases, DO increases
b) As BOD increases, DO decreases
c) It depends on the water body and the surrounding environment
d) No such relation exists between BOD & DO
Answer: b

Question: In a aquatic food chain polluted by DDT, the tissue concentration of DDT would be highest in
a) Aquatic weed
b) Herbivorous fish
c) Carnivorous fish
d) Bird feeding on fish
Answer: d

Question: Green muffler is used against which type of pollution?
a) Air
b) Soil
c) Water
d) Meter
Answer: d

Question: The effect of today’s radioactive fallout will be harmful to children of future generations because
a) Infants are more susceptible to radiations
b) Susceptibility to radiation increases with age
c) Mutated genes are frequently recessive
d) Contamination of milk supply is not cumulative
Answer: c

Question: In treatment of waste water, biological treatment is –
a) Secondary treatment
b) Primary treatment
c) Tertiary treatment
d) Reverse osmosis stage
Answer: a

Question: There are working, ‘Eco San’ toilets in areas of –
a) Kerala
b) Bihar
c) Assam
d) Mumbai
Answer: a

Question: When domestic sewage mixes with river water –
a) Small animals like rats will die after drinking river water
b) The increased microbial activity releases micronutrients such as iron
c) The increased microbial activity uses up dissolved oxygen
d) The river water is still suitable for drinking as impurities are only about 0.1%
Answer: c

Question: By what degrees has the mean global temperature increased in the 20th century?
a) 0.2%
b) 0.4%
c) 0.6%
d) 0.8%
Answer: c

Question: DOT causes –
a) Air pollution
b) Water pollution
c) Soil pollution
d) All of the above
Answer: d

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

Question: Two lakes, A & B are identical in all aspects except that lake A has higher temperature. Which of the following is true?
a) A has higher rate of oxygen dissolution
b) B has higher rate of oxygen dissolution
c) Oxygen dissolution of both is the same
d) Both have same BOD
Answer: b

Question: Biological oxygen demand of _____ is the least.
a) Sewage
b) Sea water
c) Pure water
d) Polluted water
Answer: c

Question: Which method is used for the removal of sulphur dioxide and ammonia from the polluted air?
a) Wet scrubbers
b) Absorption
c) Gravitational method
d) Electrostatic precipitator
Answer: b

Question: Volcano is ___ source of pollution.
a) Artificial
b) Natural
c) Both
d) Man-made
Answer: b

Question: ____ is the first step of sewage treatment.
a) Precipitation
b) Chlorination
c) Sedimentation
d) Aeration
Answer: c

Question: In India, Jhum cultivation is practiced mainly in
a) North East states
b) Gangetic plains
c) Dobson
d) Deccan plateau
Answer: a

Question: Which of the following is a natural pollutant?
a) Smog
b) Volcanic gases
c) Strong wind
d) Gale
Answer: b

Question: BOD is ____ in polluted water and ____ in potable water.
a) More, less
b) Less, medium
c) Medium, more
d) Less, more
Answer: a

Question: The Earth Summit, 1992, was held at
a) Rio de Janeiro
b) Kyoto
c) St. Petersburg
d) Washington
Answer: a

Question: Primary pollutants used in the synthesis of photochemical smog are –
a) Unsaturated HCs
b) Oxides of nitrogen
c) Ozone
d) Both a and b
Answer: d

Question: Concentration of DOT for first trophic level (phytoplanktons) and top trophic level (fish-eating birds) is respectively in aquatic food chains if DOT is 0.003 ppb in water –
a) 0.025 ppm, 25 ppm
b) 0.003 ppm, 2 ppm
c) 0.5 ppm, 2 ppm
d) 0.04 ppm, 2 ppm
Answer: a

Question: We and our surroundings together are called…
a) Environment
b) Atmosphere
c) Lithosphere
d) Hydrosphere
Answer: a

Question: Due to eutrophication ___.
a) Water gets less harmful
b) BOD decreases
c) Algae are destroyed
d) BOD increases
Answer: d

Question: Limit of BOD prescribed by Central Pollution Control Board for the discharge of industrial and municipal wastewater into natural surface water is –
a) < 30 ppm
b) < 3.0 ppm
c) < 10 ppm
d) 100 ppm
Answer: c

Question: Choose the odd one out w.r.t. ozone depletion in the stratosphere
a) UV rays have the ability to both degrade as well as form ozone layer
b) UV rays are depleting the good ozone in the troposphere
c) CFC’s are disturbing the balance of ozone equilibrium
d) UV-B rays cause inflammation of cornea called snow blindness
Answer: b

Question: Which pollutants are responsible for bronchitis?
a) O₂, CO₂
b) CO, CO₂
c) SO₂, NO₂
d) Cl₂, H₂S
Answer: c

Question: Which method is used to control pollutants of particulate nature?
a) Combustion
b) Absorption
c) Electrostatic precipitators
d) Oxidation pond
Answer: c

Question: Identify the correct matches –
A. Environmental (protection) act, 1986 — Protection and qu ty improvement of air, water and soil.
B. Kyota protocol — To mitigate climate change, to reduce green house gases
C. Montreal protocol — ODS reduction
D. Chipko movement — Trees protection
a) A, B
b) A, B, C
c) A, B, D
d) A, B, C, D
Answer: d

Question: After the conventional sedimentation, filtering and chlorine, lots of dangerous pollutants still remain. To combat this, the biologists developed a series of six connected marshes where appropriate plants, algae, fungi and bacteria were seeded into this area, which
(A) Neutr se the pollutants
(B) Absorb the pollutants
(C) Assimilate the pollutants
a) All are correct
b) All are wrong
c) All are correct except B
d) All are correct except C
Answer: a

Question: DDTA.
is a non-degradable pollutant
B. shows biomagnification
C. is harmful to fishes and birds
D. is a pesticide
a) Only D is correct
b) Only B and G are correct
c) None is correct
d) All are correct
Answer: d

Question:
Column I                              Column II
I. Arsenic                        (A) Minamata disease
II. Nitrate                        (B) Itai-itai
III. Mercury                     (C) Blue-baby syndrome
IV. Cadmium                  (D) Skeletal fluorosis
V. Fluoride                      (E) Black-foot disease
The correct matching is –
a) !- B.ll- A, III-D, IV-E.V-C
b) l- D.ll- A.III-B, IV-C.V-E
c) l- C,ll- B, III-D, IV-A.V-E
d) l- E.ll- C, III-A,IV-B;V-D
Answer: d

Question: Which of the following will be found in polluted water?
A. B. G. A B. Larvae of stonefly C. water hyacinth D. sewage fungi
a) A,B
b) A,B,C
c) A, C, D
d) A, B, C, D
Answer: c

Question: Pollution in big cities can be controlled to a large extent by –
A. Improving traffic condition and road. B. Road side plantation
C. Proper disposal of garbage and domestic as well as municipal wastes.
D. Cannot be controlled
a) A, B
b) A, B, C
c) A, D
d) A, B, C, D
Answer: b

Question: Which of the following pair(s) is / are correctly matched?
A. fossil fuel burning – CO₂ release
B. nuclear plant- Radioactive wastes
C. CO₂ – Green house effect
D. Montreal protocol – Control O3 depletion
a) A, B
b) A,B,C
c) A, D
d) A, B, C, D
Answer: d

Question: Read the following statements given here below and select the right answer
(A) Kyota protocol, 1997 conference obtained commitments from different countries for reducing overall green house gas emission at level 5% below 1990 by 2008 – 2012
(B) Montreal protocol was signed in 1987
(C) Montreal protocol became effective in 1989
(D) Montreal protocol was signed to control the emission of ozone depleting substances.
a) All are correct
b) All are wrong
c) All are correct except A
d) All are correct except C
Answer: a

Question: Which of the following is/are correct regarding Montreal Protocol?
(i) Persistent organic pollutants,
(ii) Global warming and climate change.
(iii) To control the emission of ozone depleting substances. ‘
(iv) Biosafety of genetically modified organisms.
a) (ii) & (iii)
b) (iii) only
c) (iii) & (iv)
d) (i) & (iii)
Answer: b

Question: Of the following, pick out the constituents of a photochemical smog
A. Ozone B. Nitrogen oxides C. PAN D. H₂SO₄ E. DDT
F. BHC G. CO₂
a) A, B, C
b) A, B, C, G
c) B, C, D, G
d) A, B, C, E, F, G
Answer: a