Folio Biology Form 4
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Transcript of Folio Biology Form 4
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No. CONTENT PAGE
1. Introduction 2
2. Objective 3
3. Human Activities That Endanger An
Ecosystem
i. Causes
ii. Source
4 - 19
4. Greenhouse Effect And The Thinning Of
The Ozone Layer
20 - 25
5. Steps To Maintain A Stable
Environment
26 - 28
6. Conclusion 29
7. References 30
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I , Muhammad Amin Bin Rosnan from 4 Alfa would like to thank those who
have been indirectly or directly involved in the making of this folio titled
ENDANGERED ECOSYSTEM. Ministry Of Educations effort in organizing the
making of this folio is highly appreciated in a way of increasing students
understanding in biology. Hence, not only increasing students level of understanding,but also increasing the value of studying biology as it is related to our living. By doing
this folio, it does not only increase my understanding towards biology, also it makes
me grow enthusiastic towards the intriguing subject, biology. I have now completed a
paperwork on the topic ENDANGERED ECOSYSTEM based on the last chapter
in the form 4 syllabus.
Nevertheless, I felt relief and grateful upon having such fabulous companion and
references who were my biology teacher Madam Airin Binti Abu Bakar, my parents,
helpful friends also siblings. I was really thankful to those who have helped me
out,being supportive yet helpful especially in providing extra information on the topic
which is given to in the making of this folio. Without their help surely I will not be
able to make this folio as a satisfying piece. Not to forget to my headmaster Tuan Haji
Sabuddin Bin Haji Sani for giving the students the opportunity to make this folio. Last
but not least, thank you once again to those who has helped directly or indirectly in the
making of the folio.
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THE REASON FOR THE PAPERWORK IS BEING DONE IS DUE TO
SEVERAL OBJECTIVES AS STATED BELOW :
To evaluating human activities that endanger an ecosystem.
To understanding the greenhouse effect and the thinning of the ozone layer.
To realizing the importance of proper management of development
activities and the ecosystem.
To instill awareness among human about the importance of the preservation
and the conservation of the ecosystem.
To deduce the time for the depletion and the destruction of the environment
due to the environmental problems caused by human beings.
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Human activities that threaten the ecosystem
The worlds population might reach to 10 billion in the next fiftyyears. Hence, when
there are increments in the number of the worlds population, it generally means that
there is an increasing demand for shelter, food, medicine, transport and raw materials.
Today, due to expectation of modern living and industrial revolution, the world has to
confront the destruction of forests tobuild more houses, to being use as plantation areas
and to buildroads just to fulfill humans needs.
Unplanned developments and mismanagement of ecosystem give rise to vast amounts
of environmental crisis. Among those environmental problems are greenhouse effect,
global warming,pollution, soil erosion, landslide, flashflood and ozone depletion.
The human activities that we are talking about are like agriculture, burning or
combustion, industrialisation and last but not least, deforestation.
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Human activities made many drawbacks to the environment. Whether we like
them or not, these cons of the human activities have made all of us now leaving
in a hardship. The impacts can now be clearly seen by looking at our devastating
environment conditions.
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Large areas of forests are cleared for extracting timber or fuel wood, agricultureneeds, and for the sake of urbanisation. The impacts are enormous and
outrageous. Let see what are the drawbacks of deforestation:
1.Deforestation causes soil erosion, landslides and flash floodsWithout proper development and planning, a land stripped of its vegetation is
subject to soil erosion.
Soil erosion is the removal and thinning oh the soil layer due to physical and
climatic processes, such as high rainfalls.
The absense of plant systems makes the soil structure unstable.
When there are heavy rains for a long period of time, the top layer of the soil
crumbles and this leads to landslides on steep hillsides.
The eroded soil is then carried by moving water and deposited at the bottom of
rivers.
This, together with depletion of water catchment areas, causes flash floods
during the rainy seasons.
Soil erosion caused the land to be depleted of minerals and natural resources,
making the land infertile.
Landslides Flash flood
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2.Deforestation results in the loss of biodiversityDeforestation has a devastating effect on the biodiversity in tropical rainforests.
The destruction of millions hectares of forests by human activities means:
The removal of the bases of numerous food webs
The loss of habitats of many species of flora and fauna
The extinction of countless species and varieties of plants and animals. The
extinction of flora and fauna species reduces the biodiversity. Biodiversity can
be rich source of food and priceless medicines to mankind.
3.Deforestation causes climatic changes
Deforestation disrupts the normal weather patterns, creating hotter, drier weather
and causing global climatic changes.
The removal of trees reduces transpiration, rainfall and the rate at which plants
absorb carbon dioxide from the atmosphere during photosynthesis.
This leads to an increase in the carbon dioxide level in the atmosphere. High
levels of carbon dioxide prevent heat from escaping from the atmosphere.
This is known as the greenhouse effect which is believed to lead to global
warming.
Forest clearing and burning of wood result in air pollution and release more
carbon dioxide into the atmosphere .
Burning of trees in the tropics adds about 25% more carbon dioxide to the
atmosphere.
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Excessive use of land for intensive farming decreases the space and resources
available for other species.
In intensive farming, farmers often use inorganic fertilisers, which contain
nitrates, phosphates and potassium ions, to improve crop yields.
Since nitrate and ammonium ions are highly soluble, the do not remain in the
soil for long and are quickly leached into the surrounding rivers and lakes.
This leads to eutrophication.
Intensive farming
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The burning of fossil fuels adds about 75% of carbon dioxide tothe atmosphere.
An increase in carbon dioxide levels is associated with the greenhouse effect and
global warming.
Smoke from vehicle
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An increase in human population generates an increase in both domestic and
industrial waste.
The dumping of waste in landfills poses a great danger to living organisms as toxic
subtances and other pollutants from the dumpsites leak into the ground and
eventually pollute the nearby water sources.
Factory
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Pollution can be defined as any undesirable change in the environment due to the
release of harmful substances following undesirable human activities. There are four
types of pollution, namely:
Air Pollution
Air pollution is the change in the composition of air due to the presence of pollutants
(gases or particles) in high concentrations that can be harmful to life as well as to the
environment.
Air pollution from open burning
Air pollution
Water pollution
Thermal pollution
Noise pollution
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Sources of Air Pollution
There are various sources of air pollution. These include:
Motor vehicles use fossil fuel which emits carbon dioxide, carbon monoxide, sulphur
dioxide, dust, etc. Industries also use fossil fuel as their source of energy. Open
burning produces a great amount of smoke, dust and carbon dioxide. This in turn can
cause hazes and affect visibility and human health.
Effects of Air Pollution on Human Health
Air pollution is detrimental to human health. The continuous inhaling of polluted air
can cause various ailments such as bronchitis, emphysema and cancer of the lungs
and silicosis. It also affects the eyes, causing them to become irritated and leading toconjunctivitis and other problems.
People wearing mask
Motor vehicles
Industries
Open burning
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Effects of Air Pollution on Buildings
Air pollution also reacts with the structural components of buildings such as the brick
works, paint and the metal components.
Corrode building
Effects of Air Pollution on Plants
Air pollution also damages plants by oxidising the cellular components and enzymes
of the plants. The air pollution causes the leaves to turn yellow. This process is
known as chlorosis (a reduction in the amount of chlorophyll). Prolonged exposure to
air pollution causes the plants to weaken, be infected by diseases and eventually, the
plants die.
Dying tree
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Effects of Air Pollution on the Climate
There are various effects of air pollution on the climate such as:
The Formation of Acid Rain
The formation of acid rain involves various stages. In the first stage, the large
amounts of sulphur dioxide and nitrogen dioxide released from factories and vehicles
combine with atmospheric water vapour/droplets. This combination produces
sulphuric acid and nitric acid in the water droplets. The presence of acid in the water
droplets causes the pH to drop below 5.0.
The formation of acid
rain
The greenhouse effect
Hazes
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Eutrophication
One of the main effects of water pollution is eutrophication. Eutrophication is a
process where the water in ponds or lakes becomes rich in dissolved nutrients
(nitrates and phosphates) produced from fertilisers or sewage. The high concentration
of dissolved nutrients promotes the growth of algae and blue green bacteria which
cover up the surface of the ponds or rivers.
As a result, sunlight is prevented from reaching the algae and aquatic plants at the
bottom of the water. Photosynthesis cannot take place and they die. The
decomposition of dead plants by the aerobic bacteria uses more oxygen in the water
and reduces its concentration. This in turn increases the biochemical oxygen demand
(BOD).
The BOD is an indication of the amount of dissolved oxygen in water. A lower BOD
indicates that a high amount of oxygen has dissolved in the water while a higher
BOD indicates that a low amount of oxygen has dissolved in the water.
The BOD for clean water is less than 1 part per million (ppm; in highly polluted
water with human wastes, the BOD is between 200-400 ppm.
Algal bloom
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Noise Pollution
Noise pollution is man-made noise that disrupts the environment. Excessive noise
pollution is harmful to living organisms. The sources of noise pollution are vehicles,
aeroplanes and trains, music, entertainment and drilling machines as well as noise
caused by piling at construction sites.
Excessive and very loud noise can damage the ear drums as well as the cells in the
inner part of the ear leading to hearing loss and deafness.
The threshold of the normal sound suitable for the ear is in the range of 40-60
decibels. Sounds of higher decibels, such as the sound of a jet engine (> 125 decibels)
and piling at construction sites (>100 decibels) are not suitable for the ears and
should be avoided.
Drilling
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The Greenhouse Effect
The greenhouse effect is an effect in the atmosphere as a result of the presence of
certain gases , called the greenhouse gases.
Greenhouse gases in the atmosphere are similar to the glass panes of a greenhouse
which trap the heat and warm the greenhouse.
Carbon dioxide, cllorofluorocarbons (CFCs), methane, nitrous oxide, low level
ozone, and water vapour make up the greenhouse gases.
With the exception of CFCs, most of the greenhouse gases occur naturally.
However, all of them are also the results of human activities.
Today, data collected around the world show a steady increase in the concentration
of greenhouse gases. At the same time, there is also rapid development and
industrialisation.
Since the beginning of the Industrial Revolution, atmospheric concentrations of
carbon dioxide have increased by nearly 30%, the concentrations of methane have
more than doubled, and the concentrations nitrous oxide (N20) have risen by about
15%.
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The greenhouse effect
Scientists believe that the combustion of fossil fuels and other human activities
such as deforestation and industrial production are the primary reasons for the
increased concentration of atmospheric carbon dioxide.
As the concentration of greenhouse gases rises, the greenhouse effect increases,
trapping more heat in the atmosphere and raising the average temperature on Earth.
This overall rise in the average temperature of the atmosphere is known as global
warming. The increase in atmospheric temperature has been high enough to cause
changes in the global climate.
Over last 40 years, the average temperature on Earth has increased by about
0.2-0.3C.
In Malaysia, temperature has been rising at 0.18C every decade.
Without emission control policies, it is projected that carbon dioxide
concentrations will be 30-150% higher than the present level. The average
temperature on earth may rise between 1.5C and 4.5C by 2100.
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THE EFFECTS OF GLOBALWARMING
The Occurrence Of Floods
-As the mean temperature rises, the polarice caps and glaciers melt.
- A rise in sea levels caused low-lyingareas to be flooded.
Climatic Changes
- Global warming leads to changes inwind direction and the distribution of
rainfall. As a result, agrcultural activitiesare affected.
- Global warming causes weather patternsto change. This affects the distribution ofspecies which may lead to the extinction
of species in certain regions.
Occurence Of Drought
- Global warming increases thefrequency of droughts.
- The land becomes dry and infertile.This leads to a drop in crop yields.
Spread of Diseases
- With warmer climates, pests andvectors may spreads to new areas.
- The warmer conditions lead to anexpansion of territories for diseases-
carrying vectors, resulting in an increasein the outbreaks of diseases such as
malaria and dengue fever.
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The Thinning Of The Ozone Layer
The ozone layer is a region in the stratosphere, between 20 and 25 kilometres
above the surface of the Earth.
The ozone layer contains high con centrations of ozone molecules (O3) that
absorb ultraviolet (UV) radiation and shield organisms from its damaging effects.
The ozone layer filters out UV radiation.
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The thinning of ozone layer has been recorded by scientists since the 1970s.
In 1985, it was reported that the stratopheric ozone over the Antarctica has
declined by 40% since 1977.
The atmosphere in this area has very low ozone concentrations, resulting in the
formation of an ozone hole. An ozone hole has now appeared above the Arctics as
well.
Consequently, UV radiation has risen by 7% per decade in the southern
hemisphere.
This layer of ozone shields us from excessive ultraviolet radiation from the sun.
A satellite image of the ozone hole over the Antarctica. The dark region on
the image is actually an ozone hole.
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There are many steps can be taken to maintain the balance of nature such
as:
1. Implementation of laws:
Environment Quality Act, 1974
Controls and prevents the pollution of the environment
Controls the type of licensing, content and quality of environment
Tests and examines the samples of substances and gas fromindustries
Natural Forestry Act, 1984
-Aims at protecting and preserving our forests and wildlife
Pesticides Act, 1974
-Aims at controlling the use of pesticides
Protection of Wildlife Act, 1972
-Aims at protecting wildlife animals, birds and plants
Fisheries Act, 1985
-Aims at controlling marine pollution
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2.Use of technology:
Use modern equipment and chemicals to control oil spills.
Recycle rubbish.
To look for methods to do research.
Change organic rubbish to biogas.
Use less polluting and clean fuels in motor vehicles.
Control and treat the toxic and dangerous waste before disposing.
3.Education:
To increase the awareness and sensitivity of theindividual to the
environment.
To provide the basic knowledge of environmentalproblems and effects of
pollutions.
To teach the public the necessary skills to protect andmaintain a healthy
society.
To help the individuals to become responsible andsensitive to the
environment.
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4.Preservation and conservation of the ecosystem:
Force the development companies to replant the forest trees after
deforestation.
Remaining the mangrove swamps area so that the ecosystemis protected.
Restore the mining and used land for agriculture.
Put effort in rivers cleaning to ensure there is sufficient supplyof water in
future) Practice of biological control.
A method of controlling the animal pests by using naturalpredators insteadof using chemical substances.
Factors to choose the animals predators.
5.Efficient use of energy: Reduce the burning of coal, petroleum and other fossil fuels.
Substitute natural gas for coal at power plants.
Improve fuel efficiency in vehicles-use cars that run on energy-efficient
engines.
Use a cleaner fuel by reducing the content of sulphur in diesel and
switching to gas.
Improve energy efficiency in factories.
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The effects of unplanned development and mismanagement of the ecosystem
can lead to damaging consequences such as soil erosion, flash floods, landslides,
eutrophication ,pollution global warming, ozone depletion, climatic changes and
loss of biodiversity. There are four types of pollution which are air, water,
thermal, and noise pollution. Greenhouse gases released by various human
activities can trap heat in the atmosphere and raise the Earths average
temperature. Such an overall rise in the Earthstemperature can leads to global
warming. The thinning of ozone layer is mainly due to the accumulation of
chloroflurocarbon (CFCs)in the atmosphere. Sustainable development must take
into consideration of proper management of the ecosystem to ensure a balance
of nature is maintained.
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Biology Form 4 Text Book.
Success (Oxford Fajar) Biology ( 2013 edition ) reference books.