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Biology M.C.Q (1 Marks)

Environmental Issues · CBSE STD 12 Science (CBSE - English Medium). 282 questions.

Questions · Page 2 of 6

M.C.Q (1 Marks)

MCQ 511 Mark
Freon gas causing stratospheric $O_3$​ depletion is mainly released from:
  • ✓
    Refrigerator
  • B
    Automobile
  • C
    Thermal power plant
  • D
    Steel industry
Answer
Correct option: A.
Refrigerator
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MCQ 521 Mark
Neem leaves or turmeric are used specifically in grain storage as:
  • ✓
    Biopesticides
  • B
    Biofertilizers
  • C
    Both $A$ and $B$
  • D
    None of the above
Answer
Correct option: A.
Biopesticides
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MCQ 531 Mark
Atmosphere of big$/$metropolitan cities is polluted most by:
  • ✓
    Automobile exhausts.
  • B
    Pesticide residue.
  • C
    Household waste.
  • D
    Radioactive fall$-$out.
Answer
Correct option: A.
Automobile exhausts.
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MCQ 541 Mark
Fish die in water bodies polluted by sewage due to:
  • A
    Pathogens.
  • B
    Clogging of gills by silt.
  • ✓
    Reduction in oxygen.
  • D
    Fuel smell.
Answer
Correct option: C.
Reduction in oxygen.
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MCQ 551 Mark
Which one of the following diseases is not due to contamination of water?
  • ✓
    Hepatitis$-B$
  • B
    Jaundice
  • C
    Cholera
  • D
    Typhoid
Answer
Correct option: A.
Hepatitis$-B$
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MCQ 561 Mark
Global warming is a direct result of:
  • ✓
    An increased imbalance of gases in the atmosphere.
  • B
    A decreased imbalance of gases in the atmosphere.
  • C
    An increased balance of gases in the atmosphere.
  • D
    None of these
Answer
Correct option: A.
An increased imbalance of gases in the atmosphere.
Global warming is a direct result of the increased imbalance of gases in the atmosphere.
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MCQ 571 Mark
Which one of the following impurities is easiest to remove from wastewater?
  • A
    Bacteria.
  • B
    Colloids.
  • C
    Dissolved solids.
  • ✓
    Suspended solids.
Answer
Correct option: D.
Suspended solids.
Suspended solids can be removed by sedimentation and decantation. Dissolved solids can be removed by evaporation of water which is an energy intensive process. Removal of colloids needs centrifugation. Removal of bacteria involves use of bactericidal agents.
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MCQ 581 Mark
Which of the following defines the effect of deforestation on the next generation?
  • ✓
    Global warming
  • B
    Global cooling
  • C
    Both $A$ and $B$
  • D
    None of the above
Answer
Correct option: A.
Global warming
As a result of deforestation, chances of desertification, droughts, floods, etc. increase.
Deforestation can also increase the level of carbon dioxide in the Earth, it will lead to an increase in temperature $i.e.,$ global warming.
As a result, the entire natural water cycle will get disrupted. This again increases the risk of natural calamities.
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MCQ 601 Mark
Acid rains are produced by:
  • ✓
    Excess $NO_2$ and $SO_2$ from burning fossil fuels.
  • B
    Excess production of $NH_3$ by industry and coal gas.
  • C
    Excess release of carbon monoxide by incomplete combustion.
  • D
    Excess formation of $CO_2$ by combustion and animal respiration.
Answer
Correct option: A.
Excess $NO_2$ and $SO_2$ from burning fossil fuels.
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MCQ 611 Mark
In the polluted water, the values of:
  • A
    $\text{C.O.D.}$ slightly higher than $\text{B.O.D.}$
  • ✓
    $\text{C.O.D.}$ much higher than $\text{B.O.D.}$
  • C
    $\text{B.O.D.}$ slightly higher than $\text{C.O.D.}$
  • D
    $\text{B.O.D.}$ much higher than $\text{C.O.D.}$
Answer
Correct option: B.
$\text{C.O.D.}$ much higher than $\text{B.O.D.}$
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MCQ 621 Mark
Protective layer of ozone in the atmosphere exists in which layer?
  • A
    Troposphere
  • B
    Lonosphere
  • ✓
    Stratosphere
  • D
    Atmosphere
Answer
Correct option: C.
Stratosphere
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MCQ 631 Mark
Lead concentration in blood is considered alarming if it is:
  • A
    $20\ mg/ 100\ mL$
  • ✓
    $30\ mg/ 100\ mL$
  • C
    $4-6\ mg/ 100\ mL$
  • D
    $10\ mg/ 100\ mL$
Answer
Correct option: B.
$30\ mg/ 100\ mL$
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MCQ 641 Mark
The loudness of a sound that a person can withstand without discomfort is about.
  • A
    $30\ dB$
  • B
    $215\ dB$
  • C
    $150\ dB$
  • ✓
    $80\ dB$
Answer
Correct option: D.
$80\ dB$
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MCQ 651 Mark
The major contributor of green$-$house gases to the atmosphere is:
  • A
    Russia
  • ✓
    $\text{USA}$
  • C
    Germany
  • D
    Brazil
Answer
Correct option: B.
$\text{USA}$
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MCQ 661 Mark
Peak concentration of ozone occurs in the atmosphere above a height of:
  • A
    $10\ km$
  • B
    $15\ km$
  • C
    $17\ km$
  • ✓
    $25\ km$
Answer
Correct option: D.
$25\ km$
The stratosphere, of the atmosphere, contains the ozone.
It protects us from harmful ultraviolet radiations. It is the layer which that extends approximately $50\ km ($about $30$ miles$)$ above earth's surface.
Peak concentrations of ozone are found at altitudes from $20$ to $25\ km.$
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MCQ 671 Mark
The material generally used for sound proofing of rooms like a recording studio and auditorium, etc. is:
  • A
    Cotton.
  • B
    Coir.
  • C
    Wood.
  • ✓
    Styro foam.
Answer
Correct option: D.
Styro foam.
Styro foam prevents reflection of sound waves instead it absorbs them after their collision.
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MCQ 681 Mark
Plantation of saplings on a large scale is celebrated as:
  • A
    Afforestation day
  • ✓
    Vanamahotsava
  • C
    Deforestation day
  • D
    Plantation day
Answer
Correct option: B.
Vanamahotsava
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MCQ 691 Mark
Which of the following falls under the category of e$-$waste?
  • ✓
    Mobile phone
  • B
    Oil tanks
  • C
    Chemical equipment
  • D
    None of the above
Answer
Correct option: A.
Mobile phone
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MCQ 701 Mark
Presence of $\text{CFCs}$ in the atmosphere is responsible for:
  • A
    Formation of ozone
  • B
    Production of healthy plants
  • ✓
    Depletion of ozone layer
  • D
    None of these
Answer
Correct option: C.
Depletion of ozone layer
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MCQ 711 Mark
Good ozone is found in :
  • A
    Atmosphere
  • B
    Biosphere
  • ✓
    Stratosphere
  • D
    Ozonosphere
Answer
Correct option: C.
Stratosphere
Ozone occurs in the Earth's upper atmosphere $-10$ to $30$ miles above the Earth's surface and protects from the sun's harmful ultraviolet $\text{(UV)}$ rays Stratospheric ozone is formed naturally by chemical reactions involving solar ultraviolet radiation $($sunlight$)$ and oxygen molecules.
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MCQ 721 Mark
Match the items in column $I$ and column $II$ and choose the correct option:
 
Column $I$
 
Column $II$
$A$
$\text{UV}$
 $i$
Biomagnificatron
$B$
Biodegradable Organic matter
 $ii$
Eutrophication
$C$
$\text{DDT}$
 $iii$
Snow blindness
$D$
Phosphates
 $iv$
$\text{BOD}$
The correct match is:
  • A
    $\text{A-ii, B-i, C-iv, D-iii}$
  • B
    $\text{A-iii, B-ii, C-iv, D-i}$
  • ✓
    $\text{A-iii, B-iv, C-i, D-ii}$
  • D
    $\text{A-iii, B-I, C-iv, D-i}$
Answer
Correct option: C.
$\text{A-iii, B-iv, C-i, D-ii}$
 
Column $I$
 
Column $II$
$A.$
$\text{UV}$
 $iii$
Snow blindness
$B.$
Biodegradable Organic matter
 $iv$
$\text{BOD}$
$C.$
$\text{DDT}$
 $i$
Biomagnificatron
$D.$
Phosphates
 $ii$
Eutrophication
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MCQ 731 Mark
What is the intensity of sound in normal conversation?
  • A
    $10-20\ dB$
  • ✓
    $30-60\ dB$
  • C
    $70-90\ dB$
  • D
    $120-150\ dB$
Answer
Correct option: B.
$30-60\ dB$
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MCQ 741 Mark
What immediate hazard is likely to occur if the temperature of the earth rises by $5^\circ C?$
  • A
    Increase in productivity
  • ✓
    Melting of polar ice
  • C
    Destruction of phytoplanktons
  • D
    Inundation of coastal towns
Answer
Correct option: B.
Melting of polar ice
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MCQ 751 Mark
In $1984,$ the Bhopal gas tragedy took place because methyl isocyanate.
  • A
    Reacted with $\text{DDT}.$
  • B
    Reacted with ammonia.
  • C
    Reacted with $CO_2$.
  • ✓
    Reacted with water.
Answer
Correct option: D.
Reacted with water.
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MCQ 761 Mark
$\text{BOD}$ stands for:
  • A
    Biological organism death.
  • B
    Biochemical organic matter decay.
  • C
    Biotic oxidation demand.
  • ✓
    Biochemical oxygen demand.
Answer
Correct option: D.
Biochemical oxygen demand.
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MCQ 771 Mark
When huge amount of sewage is dumped into a river, its $\text{BOD}$ will:
  • ✓
    Increase.
  • B
    Decrease.
  • C
    Sharply decrease.
  • D
    Remain unchanged.
Answer
Correct option: A.
Increase.
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MCQ 781 Mark
For how long and at what temperature an experiment is run to determine the value of $\text{BOD}$ of a water body?
  • A
    $10^\circ C$ for $10$ days
  • ✓
    $20^\circ C$ for $5$ days
  • C
    $20^\circ C$ for $2$ days
  • D
    $5^\circ C$ for $20$ days
Answer
Correct option: B.
$20^\circ C$ for $5$ days
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MCQ 791 Mark
Which component of the cooked food should not be disposed off into the drain?
  • A
    Dry vegetables
  • ✓
    Oil$/$ghee
  • C
    Supernatent liquid
  • D
    None of the above
Answer
Correct option: B.
Oil$/$ghee
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MCQ 801 Mark
Highest $\text{DDT}$ deposition shall occur in:
  • A
    Phytoplankton.
  • ✓
    Sea gull$/$ birds.
  • C
    Crab.
  • D
    Eel.
Answer
Correct option: B.
Sea gull$/$ birds.
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MCQ 811 Mark
If there was no $CO_2$ in the earth’s atmosphere the temperature of earth’s surface would be:
  • A
    Same as present.
  • ✓
    Less than the present.
  • C
    Higher than the present.
  • D
    Dependent on the amount of oxygen in the atmosphere.
Answer
Correct option: B.
Less than the present.
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MCQ 821 Mark
The supersonic jets cause pollution by the thinning of:
  • A
    $\mathrm{CO}_2$ layer.
  • B
    $\mathrm{SO}_2$ layer.
  • C
    $\mathrm{O}_2$ layer.
  • ✓
    $\mathrm{O}_3$ layer.
Answer
Correct option: D.
$\mathrm{O}_3$ layer.
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MCQ 831 Mark
Environment is warmed up by:
  • A
    Water vapour
  • B
    Methane
  • C
    $\mathrm{CO}_2$
  • ✓
    All of the above
Answer
Correct option: D.
All of the above
The greenhouse effect is caused by the greenhouse gases. The gases methane, carbon dioxide, and water vapour trap the solar radiations which need to be reflected back to the atmosphere and increase the temperature of the earth.
The greenhouse is considered as the direct cause of global warming.
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MCQ 841 Mark
Which of the following provides nutrients to the seedlings to grow in forests?
  • A
    Bacteria
  • B
    Fungi
  • ✓
    Decaying animal dung
  • D
    Beetles and grubs
Answer
Correct option: C.
Decaying animal dung
Animals living in the forest include herbivores and carnivores. The dung of these animals are decomposed by insects living in the soil.
This contributes to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that is trapped by bacteria in the soil. This provides nutrients to the seedlings to grow in forests.
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MCQ 851 Mark
Compressed Natural Gas $\ce{(CNG)}$ is:
  • A
    Propane
  • ✓
    Methane
  • C
    Ethane
  • D
    Butane
Answer
Correct option: B.
Methane
Compressed Natural Gas $\ce{(CNG)}$ is methane.
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MCQ 861 Mark
Calcium metabolism in birds gets disturbed due to the effect of:
  • A
    Mercury
  • B
    Cadmium
  • ✓
    $\text{DDT}$
  • D
    Copper
Answer
Correct option: C.
$\text{DDT}$
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MCQ 871 Mark
Limit of $\text{BOD}$ prescribed by Central Pollution Control Board, for the discharge of industrial and municipal waste waters into the surface water is:
  • A
    $< 100 \ \text{ppm}$
  • ✓
    $< 30 \ \text{ppm}$
  • C
    $< 3.0 \ \text{ppm}$
  • D
    $< 10 \ \text{ppm}$
Answer
Correct option: B.
$< 30 \ \text{ppm}$
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MCQ 881 Mark
The thickness of ozone is measured as:
  • A
    Parts per billion.
  • ✓
    Dobson units.
  • C
    Parts per million.
  • D
    Decibel.
Answer
Correct option: B.
Dobson units.
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MCQ 891 Mark
The $\text{BOD}$ of an eutrophied lake will be:
  • ✓
    Higher
  • B
    Lower
  • C
    Moderate
  • D
    Same as any other lake
Answer
Correct option: A.
Higher
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MCQ 901 Mark
Frequent floods in plains of Northern India is due to:
  • A
    Excessive rainfall
  • B
    Siltation of dams
  • ✓
    Deforestation in catchment areas
  • D
    Agriculture
Answer
Correct option: C.
Deforestation in catchment areas
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MCQ 911 Mark
To improve the quality of environment $($air, water and soil$)$ the Govt. of India passed the ‘Environment $($Protection$)$ Act’ in year.
  • A
    $1981$
  • ✓
    $1986$
  • C
    $1987$
  • D
    $1974$
Answer
Correct option: B.
$1986$
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MCQ 921 Mark
Among the following which one causes more indoor chemical pollution?
  • A
    Room spray.
  • B
    Burning cooking gas.
  • C
    Burning coal.
  • ✓
    Burning mosquito coil.
Answer
Correct option: D.
Burning mosquito coil.
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MCQ 931 Mark
The major source of noise pollution, world wide is due to:
  • A
    Office equipment.
  • ✓
    Transport system.
  • C
    Sugar, textile and paper industries.
  • D
    Oil refineries and thermal power plants.
Answer
Correct option: B.
Transport system.
With the advent of progressing trade, commerce and industry the means and the usage of transport has also increased. Be any trade or industry, transport is the final step for its execution
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MCQ 941 Mark
Which one of the following is a wrong statement?
  • A
    Green house effect a natural phenomenon.
  • ✓
    Ozone in upper part of atmosphere is harmful to animals.
  • C
    Eutrophication is a natural phenomenon in freshwater bodies.
  • D
    Most of the forest have been lost in tropical areas.
Answer
Correct option: B.
Ozone in upper part of atmosphere is harmful to animals.
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MCQ 951 Mark
Which of the following is a secondary pollutant?
  • A
    Aerosol
  • B
    $\text{CO}$
  • ✓
    $\text{PAN}$
  • D
    $\mathrm{CO}_2$
Answer
Correct option: C.
$\text{PAN}$
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MCQ 961 Mark
World climate is threatened by increase in the concentration of:
  • A
    Oxygen
  • B
    Nitrogen
  • C
    Water vapours
  • ✓
    Carbon dioxide
Answer
Correct option: D.
Carbon dioxide
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MCQ 971 Mark
The major source of $\text{BOD}$ in the river Ganga is:
  • A
    Leaf litter
  • B
    Fishes
  • ✓
    Human waste
  • D
    Aquatic plants
Answer
Correct option: C.
Human waste
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MCQ 981 Mark
Bio$-$agents such as culture of blue green algae are used in preparation of:
  • ✓
    Biofertilizers
  • B
    Chemical fertilizers
  • C
    Pesticides
  • D
    Manure
Answer
Correct option: A.
Biofertilizers
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MCQ 991 Mark
Effect of today's radioactive fall out will be more on future children than on present$-$day children as:
  • A
    Radiations have delayed effect.
  • ✓
    Mutated genes are usually recessive.
  • C
    Infant susceptibility to radiations.
  • D
    Increase of susceptibility to radiations with age.
Answer
Correct option: B.
Mutated genes are usually recessive.
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MCQ 1001 Mark
Which of the following gases is regarded as an atmospheric pollutant?
  • A
    $\mathrm{O}_2$
  • B
    $\mathrm{O}_3$
  • ✓
    $\mathrm{SO}_2$
  • D
    $\mathrm{N}_2$
Answer
Correct option: C.
$\mathrm{SO}_2$
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M.C.Q (1 Marks) - Page 2 - Biology STD 12 Science Questions - Vidyadip