CBSE Class 12 Biology Environmental Issues MCQs Set A

Question :  Non-biodegradable pollutants are created by

a) humans

b) natural disasters

c) excessive use of resources

d) nature

Answer :  humans

Question :  According to the Central Pollution Control Board, particles that are responsible for causing great harm to human health are of diameter

a) 2.50 micrometers

b) 5.00 micrometers

c) 10.00 micrometers

d) 7.5 micrometers

Answer :  2.50 micrometers

Question :  The material generally used for sound proofing of rooms like a recording studio and auditorium, etc. is:

a) styro foam

b) wood

c) coir

d) cotton

Answer :  styro foam

Question :  Compressed Natural Gas (CNG) is

a) methane

b) ethane

c) butane

d) propane

Answer :  methane

Question :  World’s most problematic aquatic weed is

a) Eichornia

b) Wolffia

c) Azolla

d) Trapa

Answer :  Eichornia

Question :  Which of the following causes biomagnification?

a) Both

b) Mercury

c) DDT

d) None of these

Answer :  Both

Question :  The expanded form of DDT is

a) dichloro diphenyl trichloroethane

b) dichloro diethyl trichloroethane

c) dichloro dipyrydyl trichloroethane

d) dichloro diphenyl tetrachloroacetate

Answer :  dichloro diphenyl trichloroethane

Question :  Which of the following material takes the longest time for biodegradation?

a) Bone

b) Jute

c) Paper

d) Cotton

Answer :  Bone

Question :  Which one of the following is a wrong statement?

a) Ozone in upper part of atmosphere is harmful to animals

b) Ozone in upper part of atmosphere is harmful to animals

c) Eutrophication is a natural phenomenon in freshwater bodies

d) Eutrophication is a natural phenomenon in freshwater bodies

Answer :  Ozone in upper part of atmosphere is harmful to animals

Question :  In an area where DDT had been used extensively, the population of birds declined significantly because

a) Many of the birds eggs laid, did not hatch,

b) Birds stopped laying eggs

c) Earthworms in the area got eradicated

d) Earthworms in the area got eradicated

Answer :  Many of the birds eggs laid, did not hatch,

Question :  Choose the incorrect statement

a) Dobson units are used to measure oxygen content

b) Use of incinerators is crucial to disposal of hospital wastes

c) Methane and carbon dioxide are green house gases

d) None of these

Answer :  Dobson units are used to measure oxygen content

Question :  Among the following which one causes more indoor chemical pollution?

a) burning mosquito coil

b) room spray

c) burning cooking gas

d) burning coal

Answer :  burning mosquito coil

Question :  The green scum seen in the fresh water bodies is

a) Both

b) blue green algae

c) green algae

d) None of these

Answer :  Both

Question :  The loudness of a sound that a person can withstand without discomfort is about

a) 80 dB.

b) 30 dB

c) 215 dB

d) 150 dB

Answer :  80 dB.

Question :  The major source of noise pollution, world wide is due to

a) transport system

b) sugar, textile and paper industries

c) oil refineries and thermal power plants

d) office equipment

Answer :  transport system

Question :  Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change unburnt hydrocarbons into:

a) carbon dioxide and water

b) carbon mono oxide

c) methane

d) carbon dioxide and methane

Answer :  carbon dioxide and water

Question :  Measuring Biochemical Oxygen Demand (BOD) is a method used for

a) Estimating the amount of organic matter in sewage water

b) Working out the efficiency of R.B.Cs. about their capacity to carry oxygen

c) Measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale

d) None of these

Answer :  Estimating the amount of organic matter in sewage water

Question :  Shell of egg in bird becomes thin (not properly formed) due to the pollution of pesticides. This is due to interference in the activity of

a) Calmodulin

b) Mg ATPase

c) Ca ATPase

d) None of these

Answer :  Calmodulin

Question :  Which of the following in sewage treatment removes suspended solids?

a) Primary treatment

b) Sludge treatment

c) Sludge treatment

d) None of these

Answer :  Primary treatment

Question :  Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change unburnt hydrocarbons into

a) carbon dioxide and water

b) carbon mono oxide

c) methane

d) carbon dioxide and methane

Answer :  carbon dioxide and water

Question :  Why is it necessary to remove sulphur from petroleum products?

a) 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 :  To reduce the emission of sulphur dioxide in exhaust fumes

Question :  Which one of the following impurities is easiest to remove from wastewater?

a) Suspended solids

b) Dissolved solids

c) Colloids

d) Bacteria

Answer :  Suspended solids

Question :  Which one of the following diseases is not due to contamination of water?

a) Hepatitis-B

b) Jaundice

c) Cholera

d) Typhoid

Answer :  Hepatitis-B

Question :  Nuisance growth of aquatic plants and bloom-forming algae in natural waters is generally due to high concentrations of

a) phosphorus

b) calcium

c) sulphur

d) carbon

Answer :  phosphorus

Question :  Algal blooms impart a distinct colour to water due to

a) their pigments

b) excretion of coloured substances

c) formation of coloured chemicals in water facilitated by physiological degradation of algae

d) absorption of light by algal cell wall

Answer :  their pigments

Question :  In the textbook you came across Three Mile Island and Chernobyl disasters associated with accidental leakage of radioactive wastes. In India we had Bhopal gas tragedy. It is associated with which of the following?

a) Methyl Iso-Cyanate

b) Methy Cyanate

c) CFC’s

d) None of these

Answer :  Methyl Iso-Cyanate

Question :  Industrial melanism is an example of

a) Protective resemblance with the surrounding

b) Drug resistance

c) Defensive adaptation of skin against UV radiations

d) Darkening of skin due to industries

Answer :  Protective resemblance with the surrounding

Question :  Carbon dioxide is called green-house gas because it is

a) Transparent to sunlight but traps heat

b) Transparent to heat but traps sunlight

c) Transparent to heat but traps sunlight

d) None of these

Answer :  Transparent to sunlight but traps heat