BIOLOGY form 4 Chapter 9

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4551/2 Chapter 9 : Endanger Ecosystem 2014

The impact of human activities on the ecosystem No (a)

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Diagram shows the mankind activities

Based on your knowledge in biology, explain the harmful effect of the activities to the mankind and their surroundings. Suggest ways to overcome this problem

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Harmful effect to mankind and surrounding: P1-Industries, factories, and vehicles contribute to air pollution

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P2-Industries emit pollutant such as sulphur dioxide/oxide of nitrogen smoke/fine solid particles

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P3-Which can cause respiratory problems/asthma/bronchitis/, irritates the eye P4-oxides of nitrogen and sulphur dioxide dissolve in rain water to form acid rain P5-Makes the soil acidic and unsuitable for the cultivation of crops P6-Smoke and haze reduce light intensity cause the rate of photosynthetic decrease P7-Which subsequently reduce crop yield P8-Carbon dioxide lead to green house effect, result in an increase in the atmospheric

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P9-Climate change occur P10-How water is discharged into nearby lakes and river lead thermal pollution P11-Cause instant death /reduction of aquatic species Way to overcome :

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P12-Implementation of law to reduce pollution n P13-use unlead petrol/sewage treatment P14-(formal and informal ) education stressing ( on the concept of recycle, reuse and renew) P15-Reduce the burning of fossil P16-Use alternative energy source /using renewable energy solar energy. hyfroelectric and wind power)

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(b)

The world population is now growing drastically in order to fulfil the needs of the increasing population, area of lands have to be developed into housing areas, school, factories and highways Give an evaluation on the above statement by considering g the impacts on the environment 1 1 1 1 1 1 1 1 1 1 1 1

B1-Brings more bad impact than good impact to the environment B2-Deforestation will lead to flash flood /landslide B3-Open burning will lead to air pollution /formation of haze B4-More carbon dioxide (form open burning ) will trap heat B5-Lead to green house effect /global warming B6-Lead to changes in world climate B7-Greenhouse effect /global warming increase the earth temperature B8-Destroying flora and fauna B9-Migratin of fauna/birds B10-Lead to loss of herbs for medical purpose /timber B11-Distruption / no more water catchment area Any 10 ©

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Diagram show the human activities that may threaten the ecosystem

Explain the impact of these human activities on the ecosystem F1 Air pollution P1

Exhaust fume released by the vehicle contain carbon dioxide/ carbon monoxide/ sulphur dioxide

P2 Smoke release by the factory contain dust / soot / lead P3 Gases released by the factory contain carbon dioxide/ carbon monoxide/ sulphur dioxide / nitrogen oxide

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P4 Nitrogen oxide and sulphur dioxide dissolve in water in the clouds P5 Forming nitric acid and sulphuric acid P6 Form acid rain P7 Destroy photosynthetic tissues in leaves P8 Reduce rate of photosynthesis Module biology Trial Paper collection


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No (c)

4551/2 Chapter 9 : Endanger Ecosystem 2014 Marking scheme

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P9 Increase carbon dioxide concentration

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P10 Heat is trapped by green house gases P11 Causes green house effect // lead to increase in temperature // global warming P12 Leads to climatic change// increase sea level// flash flood F2

Water pollution

P13 Disposal of waste matter from industrial // domestic source into the water P14 Causes eutrophication // increase BOD level P15 Aquatic organism die F3

Land pollution

P16 Disposal of domestic waste on the ground P17 Increase the number of pest/ rat / cockroach / flies P18 Increase disease transmission\ (d)

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Diagram Shows evidence of development urbanization and industrial practices. TI needed to develop the rises of human population

Justify the effect of unplanned development into the ecosystem 10 F1-Industries/factories /vehicles contributes to air pollution P1-Smoke /fine solid particles can cause respiratory problem P2-Oxides of nitrogen /sulphur dioxide dissolve in rain to produce acid rain P3-(acid rain ) causing the soil become acidic/unsuitable for cultivation of crops/leaching of mineral/corrosion of metal P4-Increase carbon dioxide in atmosphere causes the green house effect. global warming F2-Industrial /domestic /agricultural activities produce waste to contribute water pollution n P5-Agro chemical /pesticides/insecticide/used by the farmer flow into the river /lead to the poisoning of aquatic organism P6-Agricultural run-off contain excess nitrate/Phosphate lead to eutrophication P7-(eutrophication ) cause the BOD value will increase thus may harm the aquatic organism P8-Effluent from electronic from electronic factories contain heavy metals/mercury/cadmium kill the aquatic organism /disturb food chain F3-Diacharged of hot water from industries/glass building cause thermal pollution P9-Increase the water temperature in the river causing dies of aquatic organism / increase the atmosphere temperature any 3F and any 7 P Module biology Trial Paper collection


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Development that is not planned and managed properly has brought negative effects to the ecosystem such as land erosion, flash flood, landslides, global warming, thinning of the ozone layer, climate change and the extinction of certain species P1: The leave canopy in the forest protects the soil from excess rain water. P2: When the forest is cleared, the soil is exposed to rain (water) / wind. P3: this will cause soil erosion P4:The soil that is exposed to wind will be blown to another area, P5: while soil that is exposed to rain water will be eroded and deposited at the bottom of the river / pond /lake. P6:The soil at the hill slopes can (also) be washed away by heavy rain water P7: resulting in land slides. P8: (The deposited soil will) cause the water level to increase rapidly when it rains and P9: this will in turn cause flash floods. P10:Wild life species will also be threatened P11: when their habitat is destroyed. P12: Global warming will occur P13:due to an increase in the Earth's temperature, P14:which is caused by excess emissions of carbon dioxide/ methane/ CFC /nitrogen dioxide (into the atmosphere). P15:These gases trap the heat that is reflected by the Earth. P16:The thinning of the ozone layer occurs P17: when the ozone layer (that protects the Earth from ultraviolet radiation) is destroyed by chlorofluorocarbons (CFC).

(f)

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Diagram shows a human activity and forest in a developing country

Discuss the effect of the activity to the environment F-The diagram shows human activity which is deforestation

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P1-Deforestation is the main cause for increasing the CO2 amount in the air P2-this lead to greenhouse effect phenomenon



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(a)

-Forest play an important role as carbon sink of earth which absorb vast amount of carbon dioxide for photosynthesis

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-Greenhouse effect phenomenon promotes global warming

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-As the temperature of world is increasing ,severe climatic change/drought occur in a certain country/melting of ice at arctic /Antarctic -Forest also act as water catchment area where rain water is absorbed and released back as water vapour to the atmosphere

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-Deforestation will cause soil erosion, because there are no more root to hold the soil

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-Deforestation damages the water catchment area and leads to flash flood -Deforestation also cause loss of biodiversity by -destruction of natural habitat -That leads to extinction of many animal and species -there also destruction of recreational sites any

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(b)

Diagram also show the activities of unplanned development in that area Discuss the effects of these activities towards the environment F1-Deforesation /uncontrolled logging E1-incrases the temperature of the earth because there ar less tree to absorb carbon dioxide /greenhouse effect //causes more areas to be expose to the winds an water /soil erosion//wind and water will erode the soil into river F2-The increase in the number of motor vehicles E2-Causes an inacrese in the concentration of carbon dioxide/carbon monoxide/lead /smoke in the air/air pollution D3-mirrooed buildings /glass building reflect heat E3-Cause thermal pollution F4-Nuclaer reactor releases hot water E4-Causes thermal pollution any 3F and 3E Module biology Trial Paper collection


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No (c)


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Diagram show a man walking past the dry lake bed of tasik Pedu in Kedah

Name the environmental problem shown in the diagram and how it occurs Explain ways overcome the environmental problem that you have stated 10 Drought /global warming Criteria: C1-increase in the carbon dioxide in atmosphere C2-Factor which contribute to increase of carbon dioxide content in the atmosphere C3-Increase in global temperature C4-Factors which contribute to the increase in global temperature 1 1 1 1 1 1 1 1 1 1 1 1

E1-Extensive cutting down of trees increases the earth temperature E2-More carbon dioxide brings about green house effect E3-incraese carbon dioxide content in the atmosphere E4-Carbon dioxide trap heat E5-Building with glasses reflect heat E6-Increase in surrounding temperature E7-Increase the frequency of drought Step to overcome the environmental problem C5: reducing burning C6: control deforestation E1-Replacing energy of fossil fuel en energy generate form wind water E2-Limit opens burning

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E3-Limit deforestation E4-Replacing after deforestation E5-Promotes green world Skill to synthesize

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Q1-Ability to relate carbon dioxide content with the increase in atmospheric tempearture and means to decrease the carbon dioxide content and temperature in the atmosphere 10

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No (d)


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Diagram show a large area of forest involved in the building of a dam

Discuss the good and bad economical and environmental effect of this development Good effect G1-Generate hydropower electricity

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G2-Aas reservoir / to store water /supply fresh water G3-Supply water for agricultural / industries G4-Place/site for recreation /tourism G5-Reduce the flood problem at the down stream Bad effect

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B1-Flooded.submerged trees /habitat of the fauna and flora B2-Less tree /plants to carry out photosynthesis B3-Amount of CO2 n the atmosphere increase B4-Incraese teh impact of green house effect / global warming

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B5-Many species of fauna and flora extinct//reduce the biodiversity B6-Reduce the flow of water at the downstream B7-Cause the populations of aquatic life st the downstream reduce B8-Reduce the land used for residential /agricultural B9-Flooded /destroy/loss of historical building /site (e)

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The world population is now growing drastically In order to fulfill the needs of the increasing population ,area of land have to be developed into housing areas,school,factories and highways Give an evaluation on the statement with impacts in the environmental E-Evaluation 1m-Impact on environment Evluation (E)

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E1-Bring more bad impact to the environment Impact on environment (I) I1-Deforestion will lead to flash flood .land slide

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I2-Open burning will lead to air pollution /formation of haze I3-More carbon dioxide ( from open burning ) trap heat Module biology Trial Paper collection


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I4-Lead to green house effect /Global warming

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I5-Lead to changes in world climate I6-Greenhouse effect /global warming incrass the earth temperature I7-Destroying flora and fauna I8-Migration of fauna/birds I10-No more/Disrupted water catchment area

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(E+any 9I) Acid rain No (a)

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Diagram shows s phenomenon X which caused by air pollution

Based on the diagram name the phenomenon and explain how it occurs 4 F -acid rain

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The formation of acid rain E1-Burning of fossil fuel coal and oil in factories/power generator station /vehicles E3- sulphur dioxide/nitrogen dioxide/carbon dioxide dissolve in the water vapour

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-to to form sulphuric acid/nitric acid/carbonic acid E5-Fall to the earth with less than 5.0 ( This called acid rain ) Any 3 E

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E2-Produces sulphur dioxide/nitrogen dioxide/carbon dioxide

(b)

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Describe the effect of the phenomenon on agriculture and aquatic ecosystem and suggest ways to prevent this phenomenon effect: acid rain : On agriculture E1-Acid rain will increase the acidity of the earth//soil become acidic leaching of minerals E2-Not suitable for cultivation /grow of crops E3-cause some minerals to become insoluble and cannot be absorbed by the plants

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Any 2E On aquatic ecosystem E1-Accumulation of insoluble aluminum ion /ions in water sources //will increase the acidity of water //reduce the water pH

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E2-Kill aquatic organism /threatens aquatic life

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The ways that can be taken: S1-Reduce teh burning of fossil fuel ( which acontains sulphur) S2-Use alternative power source which is nature friendly instead of using the fossil fuel//use solar energy/wave energy

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(c)

A group of farmers planned to develop an agriculture nearby the lake. Besides to obtaining a high agriculture yield, they suggested that the area be made into a eco-tourism area. The following are a part of the details of their planning

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State the phenomena shows in both diagrams Discuss the differences of both environmental phenomena shown in diagram A and B based on the following aspect -The cause -the effect -the ways to overcome10 criteria 1. State the type of phenomena C: Differences in the causes E: Differences in the effects S: Differences in the ways to overcome F1-( the phenomena is) acid rain The causes C1-Combustion /burning of fossil fuels in power station /factories/motor/vehicles C2-Release sulphur dioxide SO2 and in power stations factories/ motor vehicles C3-Form sulphuric acid and nitric acid when combine with water vapour C4-Fall to the earth as acid rain/hail/fog/frost/dew The effect Agriculture E1-Leaching of minerals//the soil become acidic Aquatic ecosystem : E2-Incrase acidity in the aquatic ecosystem // kill phytoplankton //destroyed photosynthetic tissues//accumulate insoluble aluminum ions in lakes and river which kill aquatic organism Module biology Trial Paper collection


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Health : E3-Acidicsoil release ions of certain heavy metals/ contaminate the supplynof drinking water //irritate the lungs make breathing difficult/asthma/bronchitis E4-Corrode metal railing bridges/damage buildings/statues/ automobiles/structures made of stone /metal historical building The ways to overcome /solution S1-Use scrubbers ( to clean up emission from power station and industrial plants) S2-use catalytic converters ( to clean up emission form vehicle exhausts) No

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(a)

z Based on the diagram explain the phenomenon and its effect and its effect to the environment Facts (F) : Name of phenomenon Explanation (E): Formation of phenomenon Effects (Ef) F-( the phenomenon ) is acid rain E1-Factories /motor vechicles released large amount of oxides of nitrogen to the atmosphere E2-and sulphur dioxide E3-Oxides of nitrogen combines woth wter vopuor (in the atmosphere) to form sulphuric acid E5-The rian falls as acid rain

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Effect: Ef1-May corrode buildings

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Ef2-Aquatic lives may die due to acidic water /low pH Ef3-Mineral in soil will be dissolved Ef4-Soil become infertile /not suitable for agriculture Ef5-Plants may die due to infertile soil/acidc soil Ef6-The ecological balance of ecosystem disrupted

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No (b)


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Diagram 9.2 shows the impact of human activity on environment.

Based on Diagram 9.2, discuss the good and bad effects of the human activity. Able to discuss the good and bad effects of the human activity. Sample answer: Good effect: G1-Produce goods / materials // any examples

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G2-Use in daily life G3-Motor vehicles for transport (Any 2) Bad effects:

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B1-Releases sulphur dioxide / nitrogen dioxide B2-Dissolve in atmospheric water vapour P1-Forms sulphuric acid / nitric acid / acid P2-Down pour as acid rain P3-Dissolves minerals in soil P4-Less fertile for plant growth P5-Releases poisonous chemicals / aluminium // other examples P6-Water in rivers / lakes lower pH P7-Upsets ecological balance P8-Death of planktons / flora / fauna P9-Destruction of food chain / web P10-Extinction of species P11-Acid cause leaves turn purple / death P12-Destroy marbles / buildings // other examples

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No (c)


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Diagram shows a phenomenon in the ecosystem due to an unplanned development

Based on diagram explain the phenomenon and its effect to the environment P1-Factories released large amount of oxides of nitrogen and sulphiur dioxide to the atmosphere

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P2-Oxides of nitrogen combines with vapour ( in atmosphere ) to form nitric acid

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P3-Sulphur dioxide combine with water vapour ( in the atmoopsheree ) to form sulphuric acid P4-The rain falls as acid rain P5-May corrode building P6-aquatic lives may die due to the acidic water /low pH P7-Minerals in soil will be washed into the rivers P8-Soil becomes infertile/not suitable for agriculture P9-Plants may die due to infertile soil /acidic soil (d)

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Diagram 9 shows one phenomenon in the ecosystem due to an unplanned development.

Based on the Diagram 9, explain the phenomenon and its effect to the environment. Factor + Explanation: F – (Name the effect) (The phenomenon) is acid rain E1 – Factors / motor vehicles / factory released large amount of nitrogen oxyde E2 - and sulfur dioxyde E3 – oxyde of nitrogen combine with water vapour (in atmosphere) to form nitric acid. E4 – sulphur dioxyde combined with water vapour (in atmosphere) to form sulphuric acid. E5 – the rain fall as the acid rain.



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Effect: 1 1 1 1 1 1 1

E1: may corrode the building E2: acidic water cause aquatic animal died. E3: minerals in soil dissolved/washed into river. E4: soil becomes infertile / not suitable for plant to growth. E5: Less yield / plant become die because the infertile soil. E6: The ecological balance of ecosystem disrupt (e)

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Diagram 9 shows a newspaper cutting on one of the effect of environmental pollution

Explain the causes of the phenomena shown in diagram and the effects on the environmental and organisms Suggest ways to minimize the effect of this phenomenon 10 C1-The cause of acid rain C2-The effect of acid rain to the environment C3-Sugesstion on how to overcome the problem Cause of acid rain: F1-The combustion of fossil fuel from power stations factories / domestic boilers/vehicles release large quantities of sulphur dioxide / SO2 and oxide of nitrogen /NO and NO2 F2-Both sulphur dioxide and oxides of nitrogen combine with water vapour in the atmosphere to form sulphuric acid and nitric acid respectively F3-They will fall back to the earth as acid rain F4-Rain is naturally acidic with pH about 5.6 due to the presence of dissolved carbonic acid F5-The pH of rain is however are less than 5.0 MAX 4 marks

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Effect of acid rain: Agriculture:

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F1-The soil becomes very acidic and unsuitable for the cultivation of crops 1



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F2-Acid rain cause the leaching of mineral such as potassium / calcium /magnesium which affect the growth of crops

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Aquatic ecosystem: F3-Acid rain cause insoluble aluminum ions to accumulate in the lakes and river. An increase in the accumulation of these ion can kill aquatic organism (such as fish/ and invertebrates)

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Health: F3-Acid rain releases the ions of certain heavy metals such as cadmium/ lead/ mercury which may contaminate / harm the supply of drinking water

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F5-Increased acidity in the aquatic ecosystem also kills phytoplankton (which changes the food chain)

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F6- Photosynthetic tissue is destroyed. Plant leaves turn yellow and fall off. The root are damaged and cannot absorb minerals

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Building F7-Metal railing and bridge corrode

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F-Limestone/stonework/marble monument are corroded due to chemical weathering Suggestion to overcome the problem: F1-Cleaning up emission form power station and industrial plants with scrubber. This process involves the spraying of water trap pollutants F2-Aleaning up emission form vehicles exhausts through the use of catalytic converters .The pollutants react with one another in the catalytic converter. The pollutant reacts with one another in the catalytic converter to produce less harmful products

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Water pollution No

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Diagram shows huamn activities which are carried out near a river Explain one type of pollution that occurs at site Q

F1-water pollution E1-Effluent /phosphate /any suitable pollutant are released from the factory release into the river F2-Thermal pollution E2-Hot water form teh factory is released into the river which reduce dissolves oxygen in the river (b)

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The farmer at site P spray a large amount of pesticide in their agriculture activity Diagram show a food chain at site R

Explain why the tissue in the food contain a higher level of pesticide molecule compared to the algae P1-Algae absorbs the contaminated water /chemicals

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P2-The tadpoles feeds on the algae P3-The chemical in the algae will accumulate in the tadpole body tissue P4-The fish feeds on the tadpole P5-Will cause the chemical (accumulated) in the body tissue of the tadpole P6-The fish will have a higher concentration of chemical in their body tissues

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(d) Explain the impact of human activities at site Q on humans Impact 1 : lack of clean water supply P1-Water effluent form factories contain numerous containmination /pollution .chemicals P2-Leads to disease example diarrhea /cholera/any suitable example which threaten health Impact 2 : reduction of fresh water fish/food /aquatic organism /natural resources P1-Lack of food/protein for human /any suitable impact and explanation P2-Destruction of food chain //aquatic organism die

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Eutrophication No (a)

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Diagram show the changes that occurs in a lake due to the human activities

Based in the diagram ,explain how the activities cause the changes in a lake 1 1

F-The condition of river is the result of eutrophication P1-Farmers use fertilizer that usually contains nitrates/phosphate P2-Fertilizer/animal waste/silage which contain nitrate /phosphate may washed out in water when they are supplied with extra nitrate/(phosphate) P4-( they may grow sa much ) that they completely cover the water P5-Block out the light intensity for plants growing beneath them P6-Photosyntehsis rate reduced P8-Plant on the top of water and beneath water eventually die P9-Their remains are good source of food becteria//bacteria decomposed the dead plant rapidly //bacteria breed rapidly

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P10-The large population of bacteria repires, using up oxygen , si there is very little oxygen left for other living organism

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P11-BOD increase

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P12-Those fosh /aquatic animal which need oxygen move to other areas or die any 10 P Module biology Trial Paper collection


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(b)

Explain the differences in BOD value between site P and Site R? 4 P1-the BOD value in site P is lower than site R

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P2-Becayuse R is at the down stream P3-More pollutants accumulated in R P4-The river water flow from agriculture area /P to palm oil factory P5-The higher/increase in organic substances in the river will increase the population f bacteria decomposition //more aquatic organism die //less oxygen dissolved in the river water (at R) /resulting the BOD to increase impact 3: Destruction of food chain

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P1-Accumulation of chemical in human P2-Through food chains/taking fresh water food P3-Caner /mutation /disease When sewage is released into the pond gradually, the number and the size of aquatic animals increase but when more sewage into the pond all the aquatic animals die (c)

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Explain how this affect the pond ecosystem and the balanced of nature sewage released gradually E1-Sewage has nitrate and phosphate salts which encourages algae growth E2-Algae is the main produce of food for aquatic organism will increase Sewage content increase

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E3-Aquatic animal will get enough food encouraging their growth and reproduction E4-The size and numbers o aquatic organism will thus increase Sewage content increase E5-Sewage increase will cause algae to grow and reproduce rapidly E6-Algae will cover the pond surface this prevent sunlight from reaching aquatic plants at the bottom of pond E7-The submerged aquatic pl ants will die as they cannot photosynthesis

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E8-The decomposition by bacteria will take place using oxygen E9-The dissolve oxygen level will drop E10-Aquatic animal will die to lack of oxygen in water Module biology Trial Paper collection


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No (d)


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Diagram show a pond nearby a factory area

Based on diagram, describe the effect of this activity to the pond, Explain the effect of this condition on the aquatic organism in pond 10 Condition of the pond is the result of eutrophication P1-Caused by nitrate form the factories leach into the pond P2-(caused by ) leaching of nitrate/phosphate form palm oil estate P3-Excess nutrient encourages the rapid growth of algae/algae bloom P4-Algae grow water than their consumes , so many die 9 without being consumed form organic matter) P5-Algae covered the surface of pond P6-restrict the penetration of light into water cause the rate of photosynthesis in aquatic plants reduced /aquatic plant die

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F2-Water pollution caused by sewage /domestic waste/human faces/garbage from rubbish dumps form residential area

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P6-Pond contains a lot of organic matter

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P7-The decaying organic matter P7-The decaying organic matter is broken down by decomposing microorganism /aerobic bacteria P8-Incrasing in the BOD result in a depletion of oxygen // reduction in the amount of dissolve oxygen in the pond

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F3-Imvalance to the aquatic food web

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P9-( the low level of oxygen dissolve) kills aquatic organism like fresh water shrimps/mayfly nymphs

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P1o-If grow and release toxic gases / hydrogen sulphide/kill fish/tubifex worms /sludge worm appear

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No (e)

Marking scheme Type of plants

: Strawberry and rose plant.

Location

: Near a natural lake.

Marks

Type of fertilizers used: Compost, lead nitrate salt, potassium nitrate, magnesium ,nitrate and phosphate Based on the detail above, explain the effect on the lake if their planning is not managed properly. F1 - the leaching of chemical fertilizer/phosphate/nitrate from agriculture area to the lake E1 - Increase the fertility of the lake E2 - Encourages eutrophication (encourage algal growth) F2 - The growth alga prevent the light from reaching the base of the lake E3 – This reduces and prevents photosynthesis by aquatic plant. E4 – Reduce the oxygen release E5 – Aquatic plants and animals die due to lack oxygen. F3 – decomposition of dead plants, animals and organic matter by saprophytic bacteria accurse E6 – This will decrease the dissolved oxygen content F5 – BOD increase the water polluted E7 – This cause the aquatic animals die. (d)

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Diagram 8.2 shows a section of a river that flows through rural and urban areas

People live in residential area complained that the river water has turned green and many Fishes die.

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Explain the phenomenon F1 : Eutrophication occur



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P1 : Farmers use fertilizers that usually contains nitrates/phosphate

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P2: Fertilizer/animal waste/silage which contain nitrate/phosphate may washed out in water when it rains/leaching/run into the river. P3: Increase the nutrient content in the river P4 : Algae in the river grow faster (when they are supplied with extra nitrate/(phosphate)/ Algal bloom P5: (they may grow so much) that they completely cover the water. P6: block the sunlight to reach the plants in the water. P7: Rate of photosynthesis decrease/ not occur P8 : The aquatic plants die P9 : Bacteria decomposed dead plant P10: Population of bacteria increase P11: oxygen in the water used up by the bacteria P12: Dissolve oxygen also reduced/ BOD increase

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P13: Caused aquatic plants and fish die Thermal pollution No

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(a)

Explain the effect of the phenomenon on the organism in the river F1-The phenomenon is thermal pollution

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E1-Thermal pollution occurs when there is an increase in the temperature of water source or excessive heat in the environment

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E2-High temperature /heat reduces the level of dissolved oxygen in water

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E3-Aerobic aquatic organism will die E4-Highg temperature can cause some aquatic organism die E5-Increase in temparature encourage some algae to grow rapidly E6-Lead to high BOD value F + any 3E Module biology Trial Paper collection


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The greenhouse effect No (b)

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The following statements are human activities in an ecosystem The use of chlorofluorocarbon in air conditioners and refrigerator Combustion of fossil fuel in the factories Based on the statement, discuss how the activities endanger the ecosystem F1-(CFC) cause depletion of ozone layer

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E1-Penetration of excess /more UV rays E2-Skin cancer/melanoma/sunburns/cataract//any suitable example E3-Reduce body immune system E4-Leaf cells and chlorophyll are easily damaged //lower rate of photosynthesis E5-Kill microorganism/phytoplankton E6-Distruption /destruction of food chain /web E7-Climatic changes//any suitable example E8-Surrounding temperature increases F2-(combustion of fossil fuel) causes acid rain //air pollution E7-Factories release a large amount of nitrogen oxide/nitrogen dioxide/sulphur dioxide/carbon monoxides/dust in the atmosphere E8-Acid rain –soil become acidic (so less suitable for the cultivation of food chain /food web E10-Photosynthetic tissue are destroyed//root damaged and cannot absorb mineral /water lower rate of photosynthesis E11-Metal railing /bridges corrodes / any suitable example

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E12-Health problem: asthma/bronchitis/and any suitable respiratory problem E13-Skin and eye irritation /conjunctivitis

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(c) (d)

Figure shows an environment phenomenon

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Describe how the phenomenon in figure occurs P1-The phenomenon is the greenhouse effect P2-Carbono dioxide ,chlorofluocarbon ( CFCs) methane , nitrous oxide and water vopour make Module biology Trial Paper collection


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up the green house gases P3-Greenhouse gases produces by burning of fossil P4-Also produced belching from cattle and anaerobic respiration in paddy field P5-Effect of deforestation P6-Sunlight enter the earth’s atmosphere P7-Most of the radiation is absorb by the earth P8-Some radiation is absorbed by th earth P9-Accumulated/imcreased concentration of green house gases trapped the radiated heat P10-Warm the atmosphere

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Suggest ways to minimize the effect of this phenomenon P1-Reduce burning of fossil fuel P2-Use alternative energy sources P2-Slow down deforestation for farming ot rice growing P4-Replant trees which have been cut down

No (a)

Marking scheme

Marks

Based on diagram a phenomenon which occurs in the earth’s atmosphere

Name this phenomenon and explain the effect of the phenomenon on the environment if the concentration levels of carbon dioxide, CO2 are increasing P1-This is called the greenhouse effect

1 1 1 1 1 1 1 1 1 1 1

P2-The increase in carbon dioxide concentration traps heat P3-Causes a rise in the earth’s temperature P4-The melting of polar ice raises the sea level Any 3P F3-Habitat destruction E5-Extinxction of flora and fauna E6-Loss of biodiversity F4-Incrase of carbon dioxide in atmosphere E7-Greenhouse effect E8-Global warming E9-Climatic change Module biology Trial Paper collection


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(b)


Figure 7 shows the events leading to the greenhouse effect

With reference to figure 7, describe the steps involved in the formation of the greenhouse effect5 by greenhouse gases such as carbon dioxide and methane

(c)

-

solar radiation warms the earth’s surface

-

heat energy is reradiated back into the atmosphere

-

some heat energy escapes into space

-

heat energy is reradiated back to the earth

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3

In many parts of the world, forests are being cut down and burned. Explain why this may be contributing to the greenhouse effect.

No (d)

in slash-and-burn agriculture, the burning trees increases the concentration of carbon dioxide in the atmosphere

1

- trees photosynthesis using carbon dioxide thus deforestation leads to less carbon dioxide being removed from atmosphere

1

- less carbon dioxide is able to be locked up in trees.

1

- As trees die and tree stumps left to rot, microbial activity during decomposition also releases carbon dioxide

1

- Carbon dioxide is greenhouse gas. It absorbs energy radiated by earth, some of these energy reradiated back thus increasing the surface temperature

1

Marking scheme Describe the other causes besides deforestation and the overall effects of the enhanced greenhouse effect.10

Marks

-

the greenhouse effect is further worsened by the combustion of fossil fuel in motor vehicles in power stations to generate electricity and in industries

1

-

these activities produce large quantities of carbon dioxide into the atmosphere

1

-

the setting up of large cattle ranches to cater for the growing human population leads to massive emissions of methane gas from the belching of these animals and the decomposition of their wastes.

1

-

As the world population strives for higher standards of living, there is an increased use of CFCs in products like air-conditioning and during the production of packaging materials Module biology Trial Paper collection


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-

The rapid decomposition of humus, combustion of fossil fuels use of nitrogen or nitrate fertilizer contributes to the production of nitrogen oxides which is another greenhouse gas

1

-

The increase in the concentration of these greenhouse gases would then lead to increasing surface temperatures on earth as they trap and reflect heat back to the earth

1

-

This may lead to an increase in photosynthesis which is about the only positive effect of an enhanced greenhouse effect

-

More alarmingly however the greenhouse effect may change the local and global climate causing a shift in vegetation and vectors

-

This may also lead to extinction of certain species of organisms which are unable to adapt to the changing environment

1 1 1

-

(e)

Glaciers may start to melt thus increasing the sea levels. This leads to flooding in low lying areas around the globe As an environmental activist, explain the green house effect and discuss some human activities that can lead to the greenhouse effect. Give suggestion to the public on measure to be taken to reduce the greenhouse effect 10 Phenomenon of green house effect: F1-the greenhouse effect is an effect in the at atmosphere as a result of presence of certain gases known as green house gases E2-Carbon dioxide, Chlorofluorocarbon (CFCs) methane, nitrous oxide and low level ozone and water vapour make up the green house gases E3-As the earth is warmed, heat in the form of infrared radiation is radiated back into the space. However. Much of this heat does not escape, instead remains trapped by the green house gases E4-At the same time, greenhouse also radiated heat ( in form of infrared radiation ) back to the earth E5-This similar to the glass planes of a green house which traps heat and warm the green house, hence the term greenhouse effect MAX 4marks

1

10

1 1 1 1 1

Factors contributing t o the greenhouse effect s F1-Burning of fossil fuel coal-fired power stations/vehicle exhausts/open burning / industrial effluents like to an increase in the amount of atmospheric co2

1

F2-logging /deforestation causes’ abundance amount of co2 in the atmosphere is not for photosynthesis

1

F3-As the concentration of green house gases rises the green house effect become more pronounced

1

F4-Biuliding with planes reflects more heat, thus worsen the green house effects

1 1

F5-As more heat is trapped, the earth’s average temperature rises leading to global warming MAX 4



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(f)


Suggestion on measure to be taken to minimize the problem E1-Reduce the burning of fossil fuels to conserve energy E2-Develop alternative sources of energy such as wind/solar/biogas/and geothermal energy E3-Reduce deforestation for farming purposes E4-Replanting after deforestation

1 1 1 1

E5-Polocies that control the emission of green house gases form industrial site must be reinforced and strictly implemented

1

E6-Promotes green world

1

Max 2 marks

2

(g)

Explain how the phenomenon happens and its effect on the environment C: causes of the phenomenon E: Effect of the phenomenon F1-this s phenomenon is called green house effect C1-combustion of fossil fuel from vehicles/factories/forest burning/coal – fire power station C2-excessive deforestation C3-Increase carbon dioxide concentration in the atmosphere caused by industries

(h)

C4-Pollutant/CFC/methane E1-Carbon dioxide traps heat /infra red light /long wave radiation E2-Increase in global/ world atmospheric temperature/ cause a rise in earth temperature/global warming E3-melting of polar ice/rise in the sea levels Suggests measure needed to be taken to overcome the phenomenon P1-use alternative source of energy to reduce the usage of fossil fuel energy generated from wind /water solar P2-Restrict open burning/forest burning /use incinerator P3-Reduce deforestation for farming/other development projects P4-Selective harvesting /logging/cut matured tree only P4-Replanting more trees which have been cut down P6-The use of technology/unleaded petrol/catalytic converter Module biology Trial Paper collection


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The thinning of ozone layer No

Marking scheme

Marks

(a)

(i) State the phenomena shows in both diagrams Discuss the differences of both environmental phenomena shown in diagram A and B based on the following aspect -The cause -the effect -the ways to overcome10 criteria 1. State the type of phenomena 2. C: Differences in the causes 3. E: Differences in the effects 4. S: Differences in the ways to overcome Diagram B F2-( the phenomena is) thinning depletion of ozone layer The causes P1-Coolant in air conditioners and refrigerators/ propellants in aerosol cans/insulating foam P2Release chlorofluorocarbon / CFC molecule P3Ultraviolet radiation ( strikes a chlorofluorocarbon /CFC molecule and ) causes a chlorine atom to break away//break the bond to release the chlorine atom P4Chorine atom ( collides and destroys the ozone molecule ( to form chlorine monoxide and oxygen molecule) P5Leaf cell and chlorophyll are damaged by ultraviolet rays// lower the rate of photosynthesis//reduce crop yield P6Ultraviolet rays kill microorganism .phyplankton//destroy//disrupt the marine food chain P7Prolonged exposure to ultraviolet radiation lead to skin cancer / melanoma/cataract /weakened the immune system P8-Green house effect/ global warming //damage the eggs of certain amphibians //wind patterns change //climatic changes P9-The ways to overcome /solution P10-Reduce/stop/ban the use of Chlorofluorocarbon /CFC P11-The world comply with the Montreal protocol to reduce the use of CFCs ( to cut the use of CFC’s in half of CFC in half by the year 1997) Any 10 Module biology Trial Paper collection


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No

Marking scheme

Marks

(b)

Diagram 8.2 shows another environmental phenomenon which has become a current topic discussion

Name this phenomenon and discuss the effect of the phenomenon on human and ecosystem The phenomenon is known as thinning/depletion of the ozone layer 1 1 1 1 1 1 1 1 1

P1-More ultraviolet ray reaches the earth surface P2-Ultra-violet ray will deteriorate/weaken thee human’s body immune system P3-An increase in the number of people suffering from skin cancer/melanoma/cataract P4-High ultraviolet rays destroy phytoplankton P5-break the food chain of marine life/the aquatic ecosystem P6-The number of stomata/chlorophyll of leaves will be reduced P7-Rate of photosynthesis decreases P8-Changes in climatic pattern No (c)

F with any 5P Marking scheme

6

Marks

Explain the concept sustained development and need for it to protect our environment F-(sustainable development refers to the measure undertaken to ensure that human activity optimally utilize Earth natural resources such that they can be replenish naturally//suitable explanation

1

P1-Sustainable development is necessary as the rate at which man is using the finite natural resources will compromise future generation‘s demands //suitable explanation

1

Necessary to exploit natural resources and at at the same time measure taken so that these resource can be replenish and be available for the future generation

1

P2-Ultimately, the natural resources, if continued to be depleted, will no longer be able to sustain human society//suitable explanation

1

P3-Which make up the surrounding we live in and survive upo n

1 1

P5-Includes proper usage of renewable resources P6-Inorder to maintain a stable ecosystem

1

F + ant 3P Module biology Trial Paper collection


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The importance of proper management of development activities and the ecosystem No

Marking scheme

Marks

(a)

Explain the important of preservation and conservation of tropical rainforest in Malaysia for the purpose of sustainable management of ecosystem 1. Sustainable management of tropical rainforest 2. Explain the importance o conservation and preservation 1

F1-replanting trees in areas that have been logged//reforestation

E1-To keep the ecosystem in their natural state (which provides aesthetic value for 1 humans)//preserve natural resource for outdoor/recreational; activities//eco-tourism //reduce stress//promotes healthy life style E2-To maintain soil fertility

1 1 E4-To avoid species extinction //to prevent extinction of flora and fauna/organism /species 1 E5-As an economic resource//source of raw material for construction industry/piling. 1 Furniture/boats/houses /production of charcoal/tannin /food / other suitable example //provide foods to human // resources for study /education /research E3-T prevent food / soil erosion/landslide/(muddy) float/(flash) flood

F2-Selecive logging E5-To maintain a balanced ecosystem / to allow maximum interaction 1 among teh living organism /biotic and abiotic factors E6-To maintain major sources of human biotic and abiotic factors

1 1 E7-Ti sustain n food web /food chain in the ecosystem E8-To prevent disruption of natural cycle of water /carbon balance oxygen between CO2 in the 1 atmosphere.//provide O 2 reduce CO2 E9-to decrease the carbon dioxide level in the atmosphere// to reduce the green house effect 1 global warming E10-to maintain the biodiversity of the forest // maintaining /increasing biodiversity 1 /complexity/veriety of organism /species /flora and fauna E11-To avoid lost of wildlife/ potential resources E12-To avoid loss of water areas //provide 1 natural water catchment area E13-Maintaining (normal) weather (pattern) by minimize climatic changes drought / harsh climate / maintain temperature E14-As a site for breeding feeding of flora and fauna serving as valuable nursery area for organism

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Marks

(b)

Based on th above information ,Explain how recycle practice able to preserve the balance of environment 10 The tree F1-Less tree will be chopped/felled P1-More CO2 absorbed by the trees for photosynthesis

1 1

P2-Avoid the increasing o CO2 in the atmosphere P3-Reudce the impact of green house effect/. Global warming P4-Less habitat of fauna and flora will be destroyed

1 1 1

P5-Reduce /avoid the extinction of fauna and flora P6-To maintain /preserve the biodiversity the oil .fuel //save energy

1 1 1 1 1

F2-Reudce the burning of oil /fuel P7-More fuel energy can be preserved for future P-Less green gases /acidic gases released P9-Reduce/avoid the impact of green house effect /acid rain The landfill will be opened F3-Less land fill will be opened P10-Landfill cause leaching /.ground water pollution

1 1

P11-Less disease /health problem caused by the improper managed landfill The Water F4-Less used water/effluent/ untreated seawage released into river P12-Reduce .avoid the impact of water pollution /avoid the extinction of aquatic organisms any 10



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(c)


Diagram show an ecosystem

Explain why the ecosystem in diagram 8.2 has to be preserved and conserved 10 1 1 1

F-Ot provides human with necessities of life P-Is a resource for food /timber to build shelter/ as a fuel/fibers for clothing F-Many plant species are original sources of pharmaceutical drugs/medicines P-New commodities, for example, new crop plants or medicinal material could be in the forest F-Allow for biological control to maintain stable population P-Regulate climatic conditions biogeochemical cycles, prevent flooding Natural ecosystem and species in the wild are beautiful P-there is much pleasure to be derived form unspoilt natural environment F-Ecotourism P-Could provide income for some countries

1 1 1 1 1 1 1

10

A paddy field area is developed into an industrial area as shown in Diagram

Discuss the good and the bad social, economic and environmental effects of this development. Good Effect (G)

Explanation (P)

G1: Provides job opportunity

P1: Improve economic status

G2: Provides infrastructure basic needs

P2: Build up schools/ clinics to upgrade quality/ better opportunity in education

G3: Provides better living condition/ convenient place for settlement

P3: Have good sanitation system/ hygienic water supply/ better electric supply Module biology Trial Paper collection


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G4: Convenient transport system

P4: Faster transportation/ save time to move from one place to another

Bad Effect (B)

Explanation (P)

B1: Area/ paddy field exposed to land reclamation

P5: During heavy rain, soil particles are washed away to the river/ water source leads to muddy flood/ leaching

B2: Habitat for flora/ fauna/ paddy field are destroyed

P6: Extinction of flora/ fauna in the area// less agricultural productivity in the area

B3: Air/ water/ thermal/ sound pollution

P7: Due to the release of pollutants into the environments// causes diseases/ bronchitis/ asthmatic/ stress// leads to decrease in health quality

B4: Increase population in the area

P8: Leads to social problems

No (d)


Marking scheme

Marks

Most of the human activities cause a lot of problems to the ecosystem. Discuss the importance of planned activities to avoid destruction of the ecosystem 10 Logging A – uncontrolled logging can cause destruction of the habitat 1 1 1 1

E – also can caused the'extinction of flora and fauna - destroy the water catchments-area so, it disturb the fresh water supply - can caused the muddy flood, flash flood, soil erosion and global warming P - So the logging activities should be planned to avoid t hose effect - Planned logging can be done by replanting logging at the certain area which contain only old timber tree.

1

Motor vehicles A - can caused air pollution because the smoke contain Plumbum, carbon monoxide, carbon d ioxide,

1

E – carbon monoxide can caused death if inhaled in large amount, because it reduced the ability of oxygen transportation by red blood cells

1

- Plumbum can cause cancer

1

- Carbon dioxide and heat from the smoke,it will increase the world temperature so it can cause global warming

1

P - So using of motor vehicle can be reduce by using car pool, use the public transportation and filter the smoke released

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Open burning A - can cause hazard E - it will decrease the distance of vision can increases the health problem related w ith lung and respiratory tract P - So it can be reduce by avoid the open burning or burn the garbage in the specific place( in close area)/incinerator

1 1 1

Farming and A agriculture 1 1 1

A – Farmer used chemical fertilizer it can cause the eutrophication E - can cause extinction of flora and f fauna P - Use organic fertilizer or increase the fertility of the soil OR A_use pesticide to kill the pest, it can caused air pollution and water pollution

1 1 1

E-can cause extinction of flora and fauna P-use biological control to control the population of pest No (e)

Marking scheme

10

Marks

(e) Discuss the importance in maintaining a balanced ecosystem in a river 1 1 1 1

F-A balanced ecosystem ina river must be maintain P1-When water pollution occurs//chemical content is very high P2-Sunlight penetration is reduced/amount of dissolved oxygen very low P3-Plants /producer do not carry out photosynthesis P4-First consumer species/herbivores/carnivores do not receive enough energy//destruction of energy flow P5-Very high decomposition .eutrophication

1 1 1 1

P6-Aquatic organisms die /extinct//destruction of food chain P7-Rover becomes shallower/causing flooding over flow of water Any5

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BIOLOGY form 4 Chapter 9

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