Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology (NCERT) - Class XII > XII Chap 16 Environmental Issues > Flashcards

XII Chap 16 Environmental Issues Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is pollution?

A

Undesirable change
physical, chemical or biological
air, water, land or soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What law did GoI pass to protect environment?

A

Environment (Protection) Act, 1986

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an electrostatic precipitator?

A

Widely used mechanism to separate pollutants in industry

Removes 99% particulate matter - electrode wires => corona => electrons, which attach to dust particles => collecting plates are grounded and attract charged dust particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a scrubber?

A

Removes gases like SO2 - sulphur dioxide;

Exhaust passed through water or lime spray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

_______ is responsible for greatest harm to human health

A

PM2.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are catalytic converters?

A

Expensive metals as catalysts, fitted into cars
Unburnt hydrocarbons in exhaust => CO2 and water
CO + NO => CO2 and Nitrogen gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why should vehicles with catalytic converters use unleaded petrol?

A

Lead inactivates the catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Air Act 1981 was amended in 1987 to include what?

A

Noise pollution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What level of noise can damage ear drums?

A

Brief exposure to 150dB or more (e.g. jet or rocket taking off)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does noise pollution affect humans?

A

Sleeplessness
Increased heart beat
Altered breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is CNG better than diesel?

A

Burns most efficiently - very little left unburnt
Cheaper
Cannot be siphoned off by thieves
Cannot be adulterated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the challenge with switching to CNG?

A

Pipelines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are stipulations of Euro III norms?

A

diesel sulphur - 350 ppm
petrol sulphur - 150 ppm
aromatic hydrocarbons - 42%

eventual goal - 50ppm and 35%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are current mass emission standards in India?

A

Bharat Stage IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much impurity makes domestic sewage unfit?

A

0.1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does disposing sewage in water cause mortality of fish?

A

lots of biodegradable organic matter => decomposers consume lot of oxygen => less oxygen for other organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What causes algal bloom?

A

Large amounts of nutrients in water => excessive growth of planktonic (free-floating) algae

=> water quality deteriorates => fish mortality (also toxic to humans)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where do water hyacinth grow abundantly?

A

Eutrophic (nutrient-rich) water bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the difference between domestic and industry waste?

A

Industry waste => more toxic substances (e.g. heavy metals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is biological magnification?

A

Increase in concentration of toxicant at success trophic levels => because toxic substance cannot be metabolised or excreted

e.g. DDT
Water 0.003 => Zooplankton 0.04 => Small fish 0.5 => Large fish 2 => Birds 25

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does DDT affect birds?

A

Disturbs calcium metabolism => thin eggshells => premature breaking

22
Q

What is eutrophication?

A

natural aging of lake by nutrient enrichment, ends in converting to land, spans thousands of years

23
Q

Young lakes are warm and as they age and eutrophication occurs, the water becomes colder and shallower. T or F?

A

False, young => cold, eutrophication => shallower + warmer

24
Q

What is Cultural or Accelerated Eutrophication?

A

Pollutants (nitrates and phosphates) accelerate lake’s aging process

25
Q

_______________ is a sustainable system for handling human waste

A

Ecological sanitation, human excreta => fertiliser

26
Q

What are sanitary landfills?

A

Substitute for open burning dumps;

waste compacted, dumped in depression and covered with dirt everyday

27
Q

What are 3 types of waste?

A

Biodegradable
Non-biodegradable
Recyclable

28
Q

______________ is critical to disposing hospital waste

A

Incinerators

29
Q

50% of the e-waste generated worldwide is dumped in ______________

A

China, India and Pakistan

30
Q

___________ is the only solution to treat e-waste

A

Recycling

31
Q

Integrated organic farming is a _________ procedure.

A

cyclical, zero-waste

32
Q

Two problems with nuclear energy?

A
  1. Accidental leakage

2. Safe disposal of radioactive waste

33
Q

What is the Greenhouse Effect?

A

Naturally occurring phenomenon - responsible for heating of Earth surface - half incoming radiation is absorbed by Earth’s surface to heat it - re-emits infrared, absorbed by atmospheric gases and radiated back to earth, heating earth again - cycle repeated many times

34
Q

What are the greenhouse gases?

A

CO2 and methane

35
Q

Bad vs good ozone

A

Bad - lower (troposphere)

Good - upper (stratosphere) - shield absorbing UV rays

36
Q

Thickness of ozone is measured in __________

A

Dobson units

37
Q

Why are UV rays dangerous to living organisms?

A

DNA and proteins absorb UV rays => breaks chemical bonds within these molecules

38
Q

What is ozone hole?

A

Large area of thinned ozone layer over Antarctic region

39
Q

What has disrupted the balance of ozone degradation and formation?

A

CFCs - refrigerants - move upwards towards stratosphere - UV acts on them and releases Cl atoms - Cl degrades ozone releasing oxygen

40
Q

Why are CFCs permanent?

A

Don’t get used up in the reaction, catalysts

41
Q

UV radiation of what wavelengths are completely absorbed by earth?

A

shorter than UV-B

42
Q

Effects of UV-B?

A
  1. Damages DNA => mutation
  2. Skin - damage, aging and cancer
  3. Cornea absorbs => inflamed => snow-blindness / cataract in eyes
43
Q

What is soil erosion and desertification?

A

fertile top-soil removed due to over cultivation, unrestricted grazing, deforestation, poor irrigation practices
=> dry patches of land
=> desert

44
Q

What is water logging and soil salinity?

A

waterlogging - irrigation without proper drainage => draws salts to the surface => thin crust of salt on land, collects at roots of plants and inhibits growth

45
Q

In India forest cover used to be ____ and it is now ____

A

30% and it is now 21.54%

46
Q

___________ is one of the main reasons for deforestation

A

Agriculture

47
Q

Slash and burn agriculture?

A

cut down forest trees, burn plant remains
ash used as fertiliser
after cultivation, area is left to recover for several years => farmers move to next area

when recovery phase is skipped -> deforestation

48
Q

Slash and burn cultivation is aka?

A

Jhum cultivation

49
Q

____________ is the most common source of pollution of water bodies

A

Domestic sewage

50
Q

Domestic sewage increases ______ and decreases _______ in receiving water bodies

A

increases biochemical oxygen demand (BOD)

decreases dissolved oxygen

Biology (NCERT) - Class XII (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions