Environmental Issues Practice Questions - DPP for NEET

 Page 1


DPP /CB38
1. (a) NO
2
 and SO
2
 after reacting with water in atmosphere produce
HNO
3
 & H
2
SO
4
 which fall down as acid rain.
2. (d) DDT residues are rapidly passed through  food chain causing
biomagnification because DDT is liposoluble.
Biomagnification, also known as bioamplification or biological
magnification, is the increase in concentration of a substance,
such as the pesticide DDT, that occurs in a food chain as a
consequence of:
-Persistence (slow to be broken down by environmental
processes)
-Food chain energetics
-Low (or non-existent) rate of internal  degradation/excretion
of the substance
(often due to water-insolubility).
3. (d) Silicosis is caused by exposure to dust containing silica.
4. (d) In secondary treatment mainly settled sewage flows to an
aerobic biological treatment stage where it comes into contact
with micro-organisms which remove and oxidise most of the
remaining organic pollutants.
5. (c) Biochemical Oxygen Demand (BOD) in  river water increases
when sewage gets mixed with river water. Biochemical oxygen
demand or biological oxygen demand (BOD) is a chemical
procedure for determining how fast biological organisms use
up oxygen in a body of water. It is used in water quality
management and assessment, ecology and environmental
science. BOD is considered as an indication of the quality of
a water source.
6. (d) 7. (a) 8. (a)
9. (b) Ozone layer is present in the stratosphere in the
atmosphere of the earth. It protects the earth from UV
rays (less than 300 nm). Hole in the ozone layer means
thining of ozone layer that allows harmful UV rays to
reach earth which cause skin diseases.
10. (a) Lots of urea and phosphate fertilizer were used in the crops
in the vicinity and the lake water turned green and stinky.
Due to this, lake near a village suffered heavy mortality of
fishes within a few days.
11. (c) If natural habitat is destroyed, wild life is affected worstly.
12. (c)
13. (d) The correct acronym is IUCN, International Union for
Conservation of Nature and Natural resources.
14. (b) Photochemical smog is made by the deposition of dust &
carbon particles on the pollutant gases and water vapours.
The gases found in photochemical smog are NO
2
, PAN, O
3
etc.
15. (a) Due to dumping of huge amount of sewage, the oxygen levels
are depleted, which are reflected in terms of BOD values of
water. The number of microbes also increases tremendously
and these also consume most of the oxygen. Thus BOD of
the river water will increase.
16. (c) Primary pollutants perist in the form they are released in the
environment. Secondary pollutants are formed by reaction
amongst the primary pollutants. Secondary pollutants are
more toxic than primary pollutants. So, DDT is a primary
pollutant.
17. (c) Bhopal gas tragedy, the world's worst industrial catastrophes
was not due to radioactive fallout, but it was because of
leakage of phosgene and methyl isocyanate gas.
18. (b) Lichens are indicators of air polution, especially of the
concentration of sulphur dioxide in the atmosphere. Air
pollutants dissovled in rain water, mainly sulphur dioxide
can damage lichens and prevent them from growing. So, lichens
are natural indicators of air pollution.
Page 2


DPP /CB38
1. (a) NO
2
 and SO
2
 after reacting with water in atmosphere produce
HNO
3
 & H
2
SO
4
 which fall down as acid rain.
2. (d) DDT residues are rapidly passed through  food chain causing
biomagnification because DDT is liposoluble.
Biomagnification, also known as bioamplification or biological
magnification, is the increase in concentration of a substance,
such as the pesticide DDT, that occurs in a food chain as a
consequence of:
-Persistence (slow to be broken down by environmental
processes)
-Food chain energetics
-Low (or non-existent) rate of internal  degradation/excretion
of the substance
(often due to water-insolubility).
3. (d) Silicosis is caused by exposure to dust containing silica.
4. (d) In secondary treatment mainly settled sewage flows to an
aerobic biological treatment stage where it comes into contact
with micro-organisms which remove and oxidise most of the
remaining organic pollutants.
5. (c) Biochemical Oxygen Demand (BOD) in  river water increases
when sewage gets mixed with river water. Biochemical oxygen
demand or biological oxygen demand (BOD) is a chemical
procedure for determining how fast biological organisms use
up oxygen in a body of water. It is used in water quality
management and assessment, ecology and environmental
science. BOD is considered as an indication of the quality of
a water source.
6. (d) 7. (a) 8. (a)
9. (b) Ozone layer is present in the stratosphere in the
atmosphere of the earth. It protects the earth from UV
rays (less than 300 nm). Hole in the ozone layer means
thining of ozone layer that allows harmful UV rays to
reach earth which cause skin diseases.
10. (a) Lots of urea and phosphate fertilizer were used in the crops
in the vicinity and the lake water turned green and stinky.
Due to this, lake near a village suffered heavy mortality of
fishes within a few days.
11. (c) If natural habitat is destroyed, wild life is affected worstly.
12. (c)
13. (d) The correct acronym is IUCN, International Union for
Conservation of Nature and Natural resources.
14. (b) Photochemical smog is made by the deposition of dust &
carbon particles on the pollutant gases and water vapours.
The gases found in photochemical smog are NO
2
, PAN, O
3
etc.
15. (a) Due to dumping of huge amount of sewage, the oxygen levels
are depleted, which are reflected in terms of BOD values of
water. The number of microbes also increases tremendously
and these also consume most of the oxygen. Thus BOD of
the river water will increase.
16. (c) Primary pollutants perist in the form they are released in the
environment. Secondary pollutants are formed by reaction
amongst the primary pollutants. Secondary pollutants are
more toxic than primary pollutants. So, DDT is a primary
pollutant.
17. (c) Bhopal gas tragedy, the world's worst industrial catastrophes
was not due to radioactive fallout, but it was because of
leakage of phosgene and methyl isocyanate gas.
18. (b) Lichens are indicators of air polution, especially of the
concentration of sulphur dioxide in the atmosphere. Air
pollutants dissovled in rain water, mainly sulphur dioxide
can damage lichens and prevent them from growing. So, lichens
are natural indicators of air pollution.
S-40
DPP/ CB
19. (b) Noise pollution causes anxiety, stress and irritability.
Adernaline hormone is released when body is under stress.
So noise pollution leads to secretion of adernaline hormone,
which provides added energy to the body to deal the stressful
situation.
20. (b)
21. (a) In the given pie diagram, greenhouse gases are shown. 'A' is
CO
2
 which is produced due to deforestation and large scale
combustion of fossil fules. 'B' is CH
4
 which is produced by
incomplete biogas combustion and is the major constituent
of biogas. 'C' is water vapour.
22. (b) Ultraviolet radiations are of three types - UV - C (100) - 280
nm), UV - B (280 - 320 nm) and UB - A (320 - 390 nm). UV
radiation of wavelengths shorter than UV-B, are almost
completely absorbed by earth's atmosphere, given that the
ozone layer is intact. But, UV-B damages DNA and mutation
may occur. It causes aging of skin, damage to skin cells and
various types of skin cancers.
23. (b) In Jhum cultivation crops are cultivated for 2-3 years without
manuring. It results in nutrient depletion, reduced moisture
retention of soil and increased soil erosion.
24. (b) 25. (c) 26. (d) 27. (b)
28. (c) Yellowing and blackening of Taj Mahal at Agra is due to SO
2
and other pollutants released by Mathura refinery.
29. (b) 30. (b) 31. (c) 32. (a) 33. (d) 34. (a)
35. (a) The ‘Jhum cultivation’ is also known as ‘Slash and burn
agriculture’.
36. (c)
37. (a) Unlike domestic sewage, waste water from industries like
petroleum, paper manufacturing, metal extraction and
processing, chemical manufacturing, etc. often contain toxic
substances, notably heavy metals (defined as elements with
density > 5g/cm
3
); such as mercury, cadmium, copper, lead
etc.) and a variety of organic compounds.
38. (b) DDT  causes egg shell thinning in birds because it inhibits
calcium ATPase.
39. (b) Friends of the Arcata Marsh (FOAM) is a non-profit
organization which for the last twenty years has advanced
knowledge and educated the public about treatment and reuse
of wastewater. The purpose of the FOAM is to stimulate
understanding of the Arcata Marsh and Wildlife Sanctuary,
its relationship with Arcata's integrated wastewater treatment
system, the surrounding watersheds and bay, and their link
with the earth's water cycle.
40. (d) The green house effect is a naturally occuring  phenomenon
that is responsible for heating of Earth’s surface and
atmosphere. Without a green house effect, the average
temperature at earth’s surface would have been around –
18°C, rather than the present average of  +15°C.
41. (a) The presence of a large amount of nutrients in water causes
excessive growth of planktons or free-floating algae to
produce algal bloom. Such algal blooms deteriorate the quality
of water, cause the mortality of fishes and impart distinct
colour to water bodies.
42. (b) A : Catalytic converter is a device incorporated in the exhaust
system of a motor vehicle, containing a catalyst for converting
pollutant gases into less harmful ones. As the exhaust passes
through the converter, unburnt hydrocarbons are converted
into carbon dioxide, water, carbon monoxide and nitric oxide
are changed to carbon dioxide and nitrogen gas respectively.
B : Electrostatic precipitator is a device that removes
suspended dust particles from a gas or exhaust by applying
a high-voltage electrostatic charge and collect the particles on
charged plates.
C : Earmuffs is a pair of soft fabric coverings, connected by
a band across the top of the head, that are worn over the ears
to protect them from cold or high noise level.
D : Land - fill is a site for the disposal of solid waste in which
refuse is buried between layers of dirt so as to fill in or
reclaim low-lying ground.
43. (a) Electrostatic precipitator is a device that removes suspended
dust particles from a gas or exhaust by applying a high-voltage
electrostatic charge and collecting the particles on charged plates.
In the given diagram of electrostatic precipitator, the parts marked
as A, B and C are respectively discharge corona, negatively
charged ions, and collection plate grounded.
44. (d)
45. (a) An algal bloom is a rapid increase in the population of
phytoplankton algae in an aquatic system. Typically only
one or a few species are involved and the bloom is recognized
by discoloration of the water resulting from the high density
of pigmented cells.