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Biology M.C.Q (1 Marks)

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

Questions · Page 4 of 6

M.C.Q (1 Marks)

MCQ 1511 Mark
If fertilisers are added to fresh water:
  • ✓
    Plants will die
  • B
    Overall animal population will increase.
  • C
    Eutrophication will occur.
  • D
    Fish population will decrease.
Answer
Correct option: A.
Plants will die
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MCQ 1521 Mark
Why is it necessary to remove sulphur from petroleum products?
  • ✓
    To reduce the emission of sulphur dioxide in exhaust fumes.
  • B
    To increase efficiency of automobiles engines.
  • C
    To use sulphur removed from petroleum for commercial purposes.
  • D
    To increase the life span of engine silencers.
Answer
Correct option: A.
To reduce the emission of sulphur dioxide in exhaust fumes.
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MCQ 1531 Mark
Electrostatic precipitator is employed to remove:
  • A
    Gaseous pollutants.
  • B
    Aerosol pollutants.
  • ✓
    Particulate matter.
  • D
    Electronic particles.
Answer
Correct option: C.
Particulate matter.
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MCQ 1541 Mark
The loudness of a sound that a person can withstand without discomfort is about:
  • A
    $150 \ dB.$
  • B
    $215\ dB.$
  • C
    $30 \ dB.$
  • ✓
    $80 \ dB.$
Answer
Correct option: D.
$80 \ dB.$
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MCQ 1551 Mark
Main cause of extinction of species from tropical areas is:
  • A
    Afforestation
  • ✓
    Deforestation
  • C
    Gamma diversity
  • D
    Delta diversity
Answer
Correct option: B.
Deforestation
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MCQ 1561 Mark
Disease caused by eating fish found in water contaminated with industrial waste having mercury is:
  • ✓
    Minamata disease.
  • B
    Blight’s disease.
  • C
    Hashimoto’s disease.
  • D
    Osteosclerosis.
Answer
Correct option: A.
Minamata disease.
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MCQ 1571 Mark
When domestic sewage mixes with river water:
  • A
    Small animals like rats will die after drinking river water.
  • B
    The increased microbial activity releases micro nutrients such as iron.
  • ✓
    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
Correct option: C.
The increased microbial activity uses up dissolved oxygen.
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MCQ 1581 Mark
Most hazardous metal pollutant of automobile exhausts is:
  • A
    Mercury
  • B
    Cadmium
  • ✓
    Lead
  • D
    Copper
Answer
Correct option: C.
Lead
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MCQ 1591 Mark
Polyblend was first developed by:
  • A
    Ramesh Chandra Dagar.
  • ✓
    Ahmed Khan.
  • C
    Khadi and Village Industries Commission.
  • D
    Indian Institute of Science.
Answer
Correct option: B.
Ahmed Khan.
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MCQ 1601 Mark
Water pollution is caused by:
  • A
    Sewage
  • B
    Domestic waste
  • C
    Food processing plant
  • ✓
    All of the above
Answer
Correct option: D.
All of the above
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MCQ 1611 Mark
The expanded form of $\ce{DDT}$ is:
  • A
    Dichloro diethyl trichloroethane.
  • ✓
    Dichloro diphenyl trichloroethane.
  • C
    Dichloro dipyrydyl trichloroethane.
  • D
    Dichloro diphenyl tetrachloroacetate.
Answer
Correct option: B.
Dichloro diphenyl trichloroethane.
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MCQ 1621 Mark
The factor responsible for depletion of ozone layer is:
  • A
    Excessive use of automobiles.
  • B
    Excessive industrial units.
  • ✓
    Excessive use of man made compounds containing chlorine and fluorine.
  • D
    Excessive deforestation.
Answer
Correct option: C.
Excessive use of man made compounds containing chlorine and fluorine.
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MCQ 1631 Mark
Drawback of $\text{DDT}$ as pesticide is:
  • A
    It becomes ineffective after some time.
  • B
    It is less effective than others.
  • ✓
    It is not easily$/$ rapidly degraded in nature.
  • D
    Its high cost.
Answer
Correct option: C.
It is not easily$/$ rapidly degraded in nature.
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MCQ 1641 Mark
Choose the incorrect statement.
  • A
    Use of incinerators is crucial to disposal of hospital wastes.
  • B
    Methane and carbon dioxide are green house gases.
  • ✓
    Dobson units are used to measure oxygen content.
  • D
    None of these.
Answer
Correct option: C.
Dobson units are used to measure oxygen content.
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MCQ 1651 Mark
Increase in the concentration of pollutants$/$ chemicals in higher trophic levels, is known as:
  • A
    Biodegradation.
  • B
    Eutrophication.
  • C
    Greenhouse effect.
  • ✓
    Biomagnification.
Answer
Correct option: D.
Biomagnification.
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MCQ 1661 Mark
Which one is not a pollutant normally?
  • A
    Hydrocarbons.
  • ✓
    Carbon dioxide.
  • C
    Carbon monoxide.
  • D
    Sulphur dioxide.
Answer
Correct option: B.
Carbon dioxide.
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MCQ 1671 Mark
Biochemical Oxygen Demand $\text{(BOD)}$ in a river water:
  • A
    Remains unchanged when algal bloom occurs.
  • B
    Has no relationship with concentration of oxygen in the water.
  • C
    Gives a measure of salmonella in the water.
  • ✓
    Increases when sewage gets mixed with river water.
Answer
Correct option: D.
Increases when sewage gets mixed with river water.
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MCQ 1681 Mark
Chernobyl nuclear tragedy occurred in:
  • ✓
    April$, 1986$
  • B
    August $6, 1945$
  • C
    August $9, 1945$
  • D
    December $3, 1984$
Answer
Correct option: A.
April$, 1986$
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MCQ 1691 Mark
Gas released during Bhopal tragedy was:
  • ✓
    Methyl isocyanate.
  • B
    Potassium isothiocyanate.
  • C
    Sodium isothiocyanate.
  • D
    Ethyl isothiocyanate.
Answer
Correct option: A.
Methyl isocyanate.
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MCQ 1701 Mark
The purpose of biological treatment of waste$-$water is to:
  • ✓
    Reduce $\text{BOD}$
  • B
    Increase $\text{BOD}$
  • C
    Reduce sedimentation
  • D
    Increase sedimentation
Answer
Correct option: A.
Reduce $\text{BOD}$
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MCQ 1711 Mark
Relative Biological Effectiveness $\text{[RBE]}$ usually refers to the damages caused by:
  • A
    Low temperature.
  • B
    High temperature.
  • ✓
    Radiation.
  • D
    Pollution.
Answer
Correct option: C.
Radiation.
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MCQ 1721 Mark
Green$-$house effect refers to:
  • A
    Production of cereals.
  • B
    Cooling of earth.
  • C
    Trapping of $UV$ rays.
  • ✓
    Warming of earth.
Answer
Correct option: D.
Warming of earth.
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MCQ 1731 Mark
Advantages of organic farming is $($are$):$
  • A
    No pollution
  • B
    Safe and hygienic food
  • C
    Maintained or better soil health
  • ✓
    All of the above
Answer
Correct option: D.
All of the above
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MCQ 1741 Mark
Which of the two expensive metals are used as catalysts by catalytic converters and are fitted into automobiles for reducing emission of poisonous gases?
  • ✓
    Platinum $-$ palladium, rhodium.
  • B
    Cadmium, rhodium.
  • C
    Copper, cadmium.
  • D
    Lead, mercury.
Answer
Correct option: A.
Platinum $-$ palladium, rhodium.
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MCQ 1751 Mark
Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change unburnt hydrocarbons into:
  • ✓
    Carbon dioxide and water.
  • B
    Carbon mono oxide.
  • C
    Methane.
  • D
    Carbon dioxide and methane.
Answer
Correct option: A.
Carbon dioxide and water.
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MCQ 1761 Mark
Increase of $\text{BOD}$ in water leads to:
  • A
    Increase in the dissolved $\mathrm{O}_2$ concentration.
  • ✓
    Decrease in the dissolved $\mathrm{O}_2$ concentration.
  • C
    Maintenance of dissolved $\mathrm{O}_2$ concentration at the same level.
  • D
    No effect on dissolved $\mathrm{O}_2$ concentration.
Answer
Correct option: B.
Decrease in the dissolved $\mathrm{O}_2$ concentration.
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MCQ 1771 Mark
Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change unburnt hydrocarbons into:
  • A
    Carbon mono oxide.
  • ✓
    Carbon dioxide and water.
  • C
    Methane.
  • D
    Carbon dioxide and methane.
Answer
Correct option: B.
Carbon dioxide and water.
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MCQ 1781 Mark
The waste water from Industries may contain toxic heavy metals having density of more than:
  • A
    $5 \mathrm{~g} / \mathrm{cm}^3$
  • ✓
    $10 \mathrm{~g} / \mathrm{cm}^3$
  • C
    $2 \mathrm{~g} / \mathrm{cm}^3$
  • D
    $15 \mathrm{~g} / \mathrm{cm}^3$
Answer
Correct option: B.
$10 \mathrm{~g} / \mathrm{cm}^3$
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MCQ 1791 Mark
The effects of radioactive pollutants depends upon:
  • A
    Rate of diffusion
  • B
    Energy releasing capacity.
  • C
    Rate of deposition of the contaminant.
  • ✓
    All of the above
Answer
Correct option: D.
All of the above
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MCQ 1801 Mark
Ozone hole refers to:
  • A
    Hole in ozone layer
  • ✓
    Reduction in thickness of ozone layer in the stratosphere.
  • C
    Reduction in thickness of ozone layer in the troposphere.
  • D
    Increase in concentration of ozone.
Answer
Correct option: B.
Reduction in thickness of ozone layer in the stratosphere.
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MCQ 1811 Mark
Choose the wrong pair:
  • A
    Salvodora - Desert
  • B
    Cenchrus - Savanna
  • C
    Quercus - Broad leaf forest
  • ✓
    Tectona - Temperate forest
Answer
Correct option: D.
Tectona - Temperate forest
Explanation: d. Tectona - Temperate forest
Tectona is commonly called teak tree. it is common in tropical deciduous forests along with Butea, Bombax, Shorea (Sal), Acacia (khair) etc.
In India, tropical deciduous forests occur in both plains and low hilly areas of North as well as South India.
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MCQ 1821 Mark
Fertilisers are a source of which types of pollution?
  • ✓
    Soil and water pollution
  • B
    Air and sound pollution
  • C
    Only soil pollution
  • D
    Only air pollution
Answer
Correct option: A.
Soil and water pollution
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MCQ 1831 Mark
The major source of noise pollution, world wide is due to:
  • A
    Sugar, textile and paper industries.
  • B
    Oil refineries and thermal power plants.
  • C
    Office equipment.
  • ✓
    Transport system.
Answer
Correct option: D.
Transport system.
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MCQ 1841 Mark
If forest area is reduced to half, which one of the following will be long term effect?
  • A
    The natives $($tribals$)$ of that area will die on account of hunger.
  • B
    Cattles of that area will die due to scarcity of fodder.
  • ✓
    The diversity in germplasm will affect the crop breeding.
  • D
    It will be converted into large desert.
Answer
Correct option: C.
The diversity in germplasm will affect the crop breeding.
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MCQ 1851 Mark
Increase in cases of skin cancer and high mutation rate are the result of:
  • ✓
    Ozone depletion.
  • B
    Acid rain.
  • C
    $\mathrm{CO}_2$ pollution.
  • D
    $\mathrm{O}_2$ pollution.
Answer
Correct option: A.
Ozone depletion.
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MCQ 1861 Mark
At what height over the earth does the ozone layer exist?
  • A
    $200\ km$
  • B
    $150\ km$
  • C
    $100\ km$
  • ✓
    $25\ km$
Answer
Correct option: D.
$25\ km$
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MCQ 1871 Mark
Phosphate pollution is mainly caused by:
  • A
    Phosphate rock only $[1997].$
  • B
    Agricultural fertilizers only.
  • C
    Sewage and phosphate rocks.
  • ✓
    Sewage and agricultural fertilizers.
Answer
Correct option: D.
Sewage and agricultural fertilizers.
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MCQ 1881 Mark
Which one of the following is responsible for causing skin cancer and mutation?
  • ✓
    Ozone depletion
  • B
    Smog formation
  • C
    Snowfall
  • D
    Smoke from aeroplane
Answer
Correct option: A.
Ozone depletion
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MCQ 1891 Mark
The presence of ozone in the atmosphere of earth:
  • A
    Hinders higher rate of photosynthesis.
  • B
    Has been responsible for increasing the average global temperature in the recent past.
  • ✓
    Helps in checking the ultra violet rays to earth.
  • D
    Is advantageous, since it supplies oxygen for people travelling in jets.
Answer
Correct option: C.
Helps in checking the ultra violet rays to earth.
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MCQ 1901 Mark
A lake with an inflow of domestic sewage rich in organic waste may result in:
  • A
    Drying of the lake very soon due to algal bloom.
  • B
    An increased production of fish due to lot of nutrients.
  • ✓
    Death of fish due to lack of oxygen.
  • D
    Increased population of aquatic food web organisms.
Answer
Correct option: C.
Death of fish due to lack of oxygen.
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MCQ 1911 Mark
World’s most problematic aquatic weed is:
  • A
    Azolla
  • B
    Trapa
  • C
    Wolffia
  • ✓
    Eichornia
Answer
Correct option: D.
Eichornia
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MCQ 1921 Mark
Which gas is released by improper or incomplete combustion and are generally emitted from vehicles?
  • A
    $\mathrm{SO}_2$​
  • ✓
    $CO$
  • C
    $NO$
  • D
    $\mathrm{CO}_2$
Answer
Correct option: B.
$CO$
Carbon Monoxide is formed by improper or incomplete combustion and is generally emitted from vehicles.
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MCQ 1931 Mark
Nuisance growth of aquatic plants and bloom$-$forming algae in natural waters is generally due to high concentrations of:
  • A
    Carbon
  • B
    Sulphur
  • C
    Calcium
  • ✓
    Phosphorus
Answer
Correct option: D.
Phosphorus
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MCQ 1941 Mark
Which one of the following organism is used as indicator of water quality?
  • A
    Beggiatoa
  • B
    Chlorella
  • C
    Azospirillum
  • ✓
    Escherichia
Answer
Correct option: D.
Escherichia
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MCQ 1951 Mark
Which of the following causes biomagnification?
  • A
    $\mathrm{SO}_2$
  • B
    Mercury
  • C
    $\text{DDT}$
  • ✓
    Both $b\ \& \ c$
Answer
Correct option: D.
Both $b\ \& \ c$
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MCQ 1961 Mark
A rapid growth of photosynthetic algae in water develops 'bloom'. How would it affect the environment of water?
  • A
    The environment becomes comfortable for all forms of life.
  • ✓
    $\mathrm{O}_2$ level is decreased or $\text{BOD}$ becomes high.
  • C
    $\mathrm{O}_2$​ level of water is increased.
  • D
    Fish production is increased.
Answer
Correct option: B.
$\mathrm{O}_2$ level is decreased or $\text{BOD}$ becomes high.
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MCQ 1971 Mark
Which of the following does not contributes to greenhouse effect?
  • A
    Carbon dioxide
  • ✓
    Carbon monoxide
  • C
    Chloro$-$fluoro carbon and Methane
  • D
    Refrigerant freon
Answer
Correct option: B.
Carbon monoxide
Greenhouse gases are the compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere.
Popular of them are carbon dioxide, methane, chloro$-$fluoro carbon, nitrous oxide, freon and ozone while carbon monoxide is silent killer gas.
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MCQ 1981 Mark
Denitrification is caused by:
  • ✓
    Pseudomonas
  • B
    Nitrobacter
  • C
    Nitrosomonas
  • D
    Azotobacter
Answer
Correct option: A.
Pseudomonas
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MCQ 1991 Mark
In coming years, skin related disorders will be more common due to:
  • A
    Air pollution.
  • B
    Use of detergents.
  • C
    Water pollution.
  • ✓
    Depletion of ozone layer.
Answer
Correct option: D.
Depletion of ozone layer.
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MCQ 2001 Mark
What is reforestation?
  • A
    Cutting of trees.
  • ✓
    Restocking of the destroyed forests by planting new trees.
  • C
    Conversion of fertile soil into forest.
  • D
    Conversion of forest into fertile soil.
Answer
Correct option: B.
Restocking of the destroyed forests by planting new trees.
Reforestation is restocking the destroyed forest by planting new trees. We should plant at least as many trees as we cut.
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