spm seminar 2014 - biology

8/11/2019 SPM Seminar 2014 - Biology

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Dynamic Ecosystem

Ecological terms

environmentmeans all the conditions that surround any living organism - both the other living things and the non-living

things or physical surroundings

a habitat means a place where plants and animals live

a population means all the members of a singlespecies that live in a habitat

a community of living

thingsmeans all the populations of different organisms living together in a habitat

an ecosystem refers to a community of animals, plants and micro-organisms, together with the habitat where they live

Biotic and Abiotic Factors

Abioticfactors are the effect of the material, non-living environment- pH, temperatureBiotic factors are the effect of all the living things in the environment - for example:

Producers Green plants. All food chains start with them, because they can make food byphotosynthesis.

Primary

consumersfeed on plant material. They are herbivores

Secondary

consumersfeed primarily on animal material. They are carnivores or omnivores - eg cats, dogs and lions.

Omnivores eat both plants and animals - eg bears and humans.

Predators kill for food. They are either secondary or tertiary consumers

Prey are the organisms that predators feed on. Examples of predator and prey species are: fox and rabbit
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev2.shtml#specieshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev2.shtml#photosynthesishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev2.shtml#photosynthesishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev2.shtml#species


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Scavengers feed on dead animals . They perform a useful cleaning-up function. Examples are crow, vulture and hyena.

Decomposersfeed on dead and decaying organisms (They do not 'eat' the food like scavengers, as they have no mouth-parts.

Instead they break down solid matter into liquids which they can absorb.) Examples: bacteria and some fungi.

Food Chains

The source of all food is the activity ofautotrophs,mainly photosynthesis by plants.

They are called producers because only they can manufacture food from inorganic raw materials. This food feeds herbivores, called primary consumers. Carnivores that feed on herbivores are called secondary consumers. Carnivores that feed on other carnivores are tertiary (or higher) consumers.Such a path of food consumption is called a food chain.

Each level of consumption in a food chain is called a trophic level.

When energy is transferred to the next trophic level, 90%of the chemical energy in the food is used up for metabolic activities andlost as heat.Only 10% of the energy in an organism is passed on to the next trophic level.

The table gives one example of a food chain and the trophic levels represented in it.

Food webs

Grass

Grasshopper

Toad

Snake

Hawk

Bacteria of

decay

In general,

Autotrophs

(Producers)

Herbivores

(Primary Consumers)

Carnivores

(Secondary, tertiary, etc. consumers)

Decomposers
http://home.comcast.net/~john.kimball1/BiologyPages/A/A.html#autotrophichttp://home.comcast.net/~john.kimball1/BiologyPages/A/A.html#autotrophichttp://home.comcast.net/~john.kimball1/BiologyPages/A/A.html#autotrophichttp://home.comcast.net/~john.kimball1/BiologyPages/A/A.html#autotrophic


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1. In its natural habitat it is unusual for an animal to eat only one particular organism, so a more realistic way of showing feedingrelationships is to draw a series of interconnecting food chains called afood web.

2. The food web below describes feeding relationships in a freshwater pond ecosystem.3. It allows you to follow the routes thatbiomass(and energy) take through the system.

Pondweed (a producer) is eaten by the mayfly nymphs, which are in eaten by both thedragonfly nymphsand the brown trout. The brown trout eat the dragonfly nymphs too.

The other producer in this web is the microscopic algae.The freshwater shrimp eats this.

The shrimpsare eaten by dragon fly nymphsand brown trout

Apyramid of biomass,which shows not the numbers of organisms at each level, but the

amount of biological material.A pyramid of biomass for the oak tree would look like this:

Pyramids of biomass are always pyramid-shapedThis table shows the relational biomass of each of the major groups in the food chain:
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#food_webhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#food_webhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#food_webhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev5.shtml#pyramid_of_biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev5.shtml#pyramid_of_biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev5.shtml#pyramid_of_biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev5.shtml#pyramid_of_biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#biomasshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/1feedingrelationshipsrev4.shtml#food_web


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Tertiary Consumers

Secondary Consumers

Primary Consumers

Producers

Co-operation

Some organisms find that they are better able to survive and reproduce by living closely together with another organism of a differentspecies. Some examples of different styles ofsymbiosisare:

1. Commensalism (+/0)

Barnacleswhich attach to a whale or scallop shell. The barnacles get a home and transport, and the whale or scallop is not undulyaffected. This type of symbiosis, where one organism benefits and the other suffers no harm, is called commensalism.The host is unaffected, while the commensal benefits.Epiphytes are commensal plants. Example orchids and ferns.Epizoites are commensal animals. Example Remora fish (on sharks)2. Mutualism (+/+)

Lichensare formed by algae and fungi living together. Algae can photosynthesise and make food which is shared by the fungus. Thefungus in turn shelters the algae from a harsh climate. This kind of mutually beneficial co-operative relationship is called mutualism.

Another example is Rhizobiumbacteria that live in root nodules of legume plants.

3. Parasitism (+/-)

A tapewormlives inside another animal, attaching itself to the host's gut and absorbing its host's food.

The host loses nutrition, and may develop weight loss, diarrhoea and vomiting. This kind of one-sided symbiosis is called parasitism.
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev7.shtml#symbiosishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev7.shtml#symbiosishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev7.shtml#symbiosishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev7.shtml#symbiosis


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Interdependence of organisms

1. All living things within an ecosystem are interdependent.2. A change in the size of one population affects all other organisms within the ecosystem. This is shown particularly clearly by the

relationship betweenpredatorandpreypopulations.

Saprophytism

Saprophytes (fungi and bacteria) obtain food from dead or decaying organisms and decompose them.

What is "ecological succession"?

1. "Ecological succession" is the observed process of change in the species structure of an ecological community over time.

2. Pioneer organisms are the first organisms to reoccupy an area which has been disturbed by a disruption.3. Typical pioneers in a succession include grasses in a plowed field or lichens on rocks.

4.

These pioneer organisms modify their environment, ultimately creating conditions which are less favorable for themselves, butestablishing conditions under which more advanced organisms can live.5. Over time, the succession occurs in a series of plant stages which leads to a stable final community which is very similar to the

plant community which originally existed in the ecosystem.6. This final stable plant community is called a climax community. This community may reach a point of stability that can last for

hundreds or thousands of years.

Succession in an unused mining pond:Submerged water plantsfloating plantsamphibious plantsland plants

Mangrove Swamps

1. Mangroves are mostly tropical trees or shrubs that grow between near mean sea level and the high spring tide mark in stableshores where they form distinct communities known as mangrove forests.

2. Mangroves are the only true viviparous plants. This means that the seed remains attached to the parent plant and germinatesbefore falling from the tree
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#predatorhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#predatorhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#predatorhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#preyhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#preyhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#preyhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#preyhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/0habitatsandpopsrev8.shtml#predator


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3. In general, mangroves can be characterized by the following attributes: Adaptations, such as specialized roots, that help them cope with their environment. The ability to exclude or filter out salt. Seeds germinate while still on the parent plant. Restricted to the mangrove environment.

Avicenniaand Sonneratia Rhizophora Bruguierasp

(pneumatophores) (prop roots) (knee-shaped Buttress roots)Question 1

uestion 2

uestion 3


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Question 4 uestion 5

Question 6 Question 7

Question 8Question 9


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Question 10


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Question 10

(b) A paddy field is developed into an industrial area as

shown in Diagram 8

Discuss the good and bad social, economic and environmental effects of this development [10m]


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Question 11


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Pollution

Pollution is the addition of substances to the environment that may be harmful to living organisms.

Atmospheric pollution

Atmospheric pollution is caused by1. The burning of wood and fossil fuels (coal, gas and oil);2. Emissions from petrol or diesel engines;3. Discharges from factories, power stations,

4.

Waste dumping;5. Agricultural livestock.

The pollutantsinvolved include: Smoke, which damages air quality and deposits soot on surfaces such as tree trunks and leaves


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Carbon dioxide, the main greenhouse gas causing climate change Methane, the second most important greenhouse gas causing climate change Sulphur dioxideand nitrogen dioxide, which mix with rainwater to form acid rain. Acid rain corrodes buildings and damagestrees and plants.

Carbon monoxide, which is poisonous to humans and animals (it reacts with haemoglobin and prevents it carrying oxygen)

Dust(produced by activities such as quarrying and mining) which may impair plants' ability to photosynthesise and people'sability to breathe

Water pollutionWater pollution is caused by the discharge of harmful substances into the sea, rivers, lakes or the water table. Pollutants include: Agrochemicalssuch asfertilisersandpesticideswhich damage aquatic ecosystems Sewage, which when dumped into rivers or the sea can kill aquatic organisms and harm human health

Chemical contaminants, discharged by factories or through sewage systems, may contaminate soil or seabeds, and have

unpredictable effects on wildlife - for example damage to reproductive organs through exposure to human sex hormones.

Slurry(a liquid manure made of animal droppings and urine) which if it drains into streams and rivers can harm aquatic wildlife Oil- spilled from oil tankers and refineries - which destroys habitats, poisons water supplies, and kills aquatic wildlife and birds

Other types of pollution

Radiation pollution- caused by either deliberate or accidental discharge ofnuclear waste- can contaminate the soil, water and air for

years.Radiation can cause cancers like leukaemia.Radioactive waste cannot be safely burnt or buried or sunk, but has to be stored and transported in lead- or glass-lined containerswhich stop the radiation from passing out.Many radioactive compounds stay radioactive for thousands of years.
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#fertilisershttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#fertilisershttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#fertilisershttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#pesticideshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#pesticideshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#pesticideshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#nuclear_wastehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#nuclear_wastehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#nuclear_wastehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#nuclear_wastehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#pesticideshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#fertilisers


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Noise pollution, caused by aircraft and other engines, road or building works, can induce stress in both humans and wildlife.

Litter- especiallynon-biodegradablelitter such as plastic and glass - can seriously degrade human habitats, as well as injuring bothhumans and wildlife.

Controlling pollution

Humans do not haveto pollute the environment as much as they do.Outputs of smoke and soot - once the main pollutants in industrial societies - have been massively reduced over the last 100 years.There are many things that could be done to reduce the impact of other types of human pollution as well.

Type of pollution Source Control measures

smoke and soot burning wood and fossil fuelssmokeless zones

smokeless fuel

carbon dioxide

carbon monoxideburning fossil fuels

burn less fossil fuel (switch to clean energy

sources)

build cleaner engines (eg catalytic converters)

reduce energy consumption

methaneburning fossil fuel, landfill waste and agricultural

livestockburn less fossil fuels

cut waste production
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#non-biodegradablehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#non-biodegradablehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#non-biodegradablehttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev8.shtml#non-biodegradable


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Type of pollution Source Control measures

cut livestock numbers

sulphur dioxide

nitrogen dioxidefossil fuels

burn less fossil fuelbuild cleaner engines

reduce energy consumption

dust factories, quarrying etcefficient air filters

stricter laws against polluters

agrochemicals:

fertilisers and

pesticides

farmsuse organic fertilisers instead

use biological pest controls instead

oil tankers, refineriesuse less oil

stricter laws against polluters

Important phenomenon:

1 Global warming

1. The earth has got steadily warmer over the last 150 years, as levels of atmospheric carbon dioxide have got steadily higher.2. Global temperature is the result of a balance between heat received from the sun and heat radiated back into space.


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3. The earth's atmosphere forms an insulating layer, keeping some - but not all - of the sun's heat in, a bit like the glass roof of agreenhouse.

4. Human activities such as burning fossil fuels for energy and transport are adding more and more carbon dioxide to theatmosphere.

5. At the same time large-scaledeforestationis reducing the number of trees and other green plants removing carbon dioxide forphotosynthesis.

6. Hence - rising carbon dioxide levels.7. Levels of atmospheric methane are also going up. Methane is produced by livestock farming, rotting plant material in marshes

and paddy fields, and by drilling for oil and gas.8. Methane and carbon dioxide aregreenhouse gases- they insulate the atmosphere so that it traps more of the sun's energy.9. This is the called thegreenhouse effect,and it is the cause ofglobal warming.10.Global warmingis the observed increase in theaverage temperature of theEarth's atmosphere andoceans in recent decades.

Results of global warmingRises of just a few degrees in world temperatures could have a dramatic impact on world climate:

global weather patterns may change, changing rainfall patterns, causing drought in some places and floods in others melting of polar ice caps could raise sea levels, causing increased coastal erosion and flooding of low-lying land - including some

major cities

2. Ozone destruction1. Chlorofluorocarbons or CFCs, used in fridges, air conditioners and aerosols, are another greenhouse gas.2. Though there are much lower levels of CFCs in the atmosphere than carbon dioxide and methane, they are thousands of

times more effective at trapping heat.

3.

They also damage the outer ozone layer of the atmosphere by breaking apart ozone molecules. The ozone layer acts like ascreen protecting us from the sun's harmful UV rays, and CFCs are causing holes to appear in the layer, allowing more UVrays to pass through, and increasing the risk of skin cancer.

UV raysCFCl3 CFCl2+ Cl
http://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#deforestationhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#deforestationhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#deforestationhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#photosynthesishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#photosynthesishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_gaseshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_gaseshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_gaseshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_effecthttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_effecthttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_effecthttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#global_warminghttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#global_warminghttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#global_warminghttp://en.wikipedia.org/wiki/Historical_temperature_recordhttp://en.wikipedia.org/wiki/Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Oceanhttp://en.wikipedia.org/wiki/Oceanhttp://en.wikipedia.org/wiki/Earth%27s_atmospherehttp://en.wikipedia.org/wiki/Historical_temperature_recordhttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#global_warminghttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_effecthttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#greenhouse_gaseshttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#photosynthesishttp://www.bbc.co.uk/schools/gcsebitesize/biology/livingthingsenvironment/3impactofhumansrev10.shtml#deforestation


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Cl + O3ClO + O2

The chlorine atom changes an ozone molecule to ordinary oxygen

ClO + O3Cl + 2 O2

The ClO from the previous reaction destroys a second ozone molecule and recreates the original chlorine atom, which canrepeatthe first reaction and continue to destroy ozone

3. Eutrophication

Eutrophicationis the pollution of a river or a pond, by the addition of artificial or natural substances, such asnitrates andphosphates,

throughfertilizers orsewage.In other terms, it is the "bloom" or great increase ofphytoplankton or algae in a water body. Negativeenvironmental effects include the depletion of oxygen in the water, or also known as the increase in BOD levels( Biochemical OxygenDemand) which induces reductions in specific fish and other animal populations.
http://en.wikipedia.org/wiki/Nitratehttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Sewagehttp://en.wikipedia.org/wiki/Phytoplanktonhttp://en.wikipedia.org/wiki/Phytoplanktonhttp://en.wikipedia.org/wiki/Sewagehttp://en.wikipedia.org/wiki/Fertilizerhttp://en.wikipedia.org/wiki/Phosphatehttp://en.wikipedia.org/wiki/Nitrate


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4. Acid rain

Acid rainis arain that is unusuallyacidic,meaning that it possesses elevated levels of hydrogen ions (lowpH). It can have harmful

effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions ofcarbon dioxide,sulfur dioxide andnitrogen

oxides which react with thewater molecules in the atmosphere to produce acids
http://en.wikipedia.org/wiki/Rainhttp://en.wikipedia.org/wiki/Acidhttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Sulfur_dioxidehttp://en.wikipedia.org/wiki/Nitrogen_oxidehttp://en.wikipedia.org/wiki/Nitrogen_oxidehttp://en.wikipedia.org/wiki/Waterhttp://en.wikipedia.org/wiki/Waterhttp://en.wikipedia.org/wiki/Nitrogen_oxidehttp://en.wikipedia.org/wiki/Nitrogen_oxidehttp://en.wikipedia.org/wiki/Sulfur_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/PHhttp://en.wikipedia.org/wiki/Acidhttp://en.wikipedia.org/wiki/Rain


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Question 1 Question 2

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6.

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8.


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10.

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15. 16.


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Question 17


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Question 18

spm seminar 2014 - biology

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