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GEE1 WEEK1-17 - NOTES
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Bachelor in Secondary Education (BSED 4101- S)
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WEEK1 : SCIENTIFIC METHOD, ENVIRONMENTAL EDICATION: ITS
DEFINITION AND IMPORTANCE ECOLOGY, AND ENVIRONMENTAL EARTH
SCIENCE
What is ecology? Ecology, the study of relationships between organisms and the environment, has been
a focus for human study for as long as we have existed as a species. Our survival has depended upon
how well we could observe variations in the environment and predict the responses of organisms to those
variations. The earliest hunters and gatherers had to know the habits of their animal prey and where to
find food plants. Later, agriculturists had to be aware of variations in weather and soils and of how such
variation might affect crops and livestock.
Brief History of
Environmental
Science
There are three
"revolutions" that play
a significant role in the
development of
environmental
science. These are
then Agricultural
Revolution, Industrial-
Medical Revolution
and Information-
Globalization
Revolution.
Agricultural revolution
can be traced back
10,000 years ago
where nomadic
lifestyles of hunters moved gradually to farming of domesticated plants and animals. This lifestyle shift
resulted to a negative effect on the environment
Landscapes undergone intense alterations and people lived longer and reproduce more resulting to an
increase in population. During this time, there was limited awareness on environmental threats.
Deforestation was unregulated causing soil erosion which was believed to have contributed to the
downfall1 of many civilizations. The mid-1700s to mid-1800s was the beginning of Industrial-Medical
Revolution. It is an Age of enlightenment, as Science continues to progress and develop. Development of
these new technologies led to pollution and other environmentally related problems. Nuclear weapons,
DDT and other pesticides and synthetic problems. Materials like plastics were produced during this time.
Population increased causing famine because food supply time. Does not increase. People started to
become more aware of the things happening around them. In fact, Ben Franklin fought against pollution in
Philadelphia as industries continue to pollute the air. In 1854, Dr. John Snow first as industries recognized
a pattern in an epidemic and linked it to the environment. He found out that contaminated water from one
pump led to the spread of cholera. Concern about the environment in the US was voiced only in the mid-
1800s by people like Henry David Thoreau.
The Information-Globalization Revolution started way back in 1950 and flourish during the 1970's. In spite
of the growing awareness on environmental threats, people growing continue to develop products and
methods that have detrimental effects to the environment. Computers were developed to gain access to
more information in a global Scale through the use of the internet. Phones and remote- sensing satellites
were invented. These developments do not only affect our personal lives, our culture and economy but it
greatly affects our environment. Continuous destruction of the environment became alarming that people
started to formed movement to raise awareness of the effects of technologies to our environment. On the
other hand, this revolution also helps increase awareness on environmental issues through the Internet.
The Environmental Era emerged in 1960 up to the present. Several environmental movements existed to
increase to increase environmental awareness. Rachel Carson published the Silent Spring" in 1962 which
helps propel the modern environmental movement and raised awareness of the dangerous effects of
pesticides and other chemicals. Another ecologist by the name of Paul Ehrlich wrote "Population Bomb"
which made predictions about the effects of Overpopulation. In 1970, the formulation of environmental
laws was deemed necessary to protect and conserve the environment to maintain the balance in nature.
It is also in 1970 that Earth Day was started to be celebrated to remind people every year that the
environment should not be taken for granted. At present, environmental scientists are busy searching for
solutions to lessen the dangerous effects brought about by technologies on the Environmental awareness
is given emphasis by the by emphasis by governments all over the world to save only planet we all live
the earth.
Branches of Ecology:
Terrestrial Ecology
Terrestrial ecology is a branch of ecology that deals with the study of land organisms and how they
interact with each other and adapt to their environment. Aside from that, the diversity and distribution
of different organisms in various terrestrial habitats are also being focused on. Terrestrial ecology has a
wide variety of applications like resources management, and in the long run, be effective for
conservation measures. Additionally, soil properties like moisture, pH, nutrient and chemical content,
and soil type may be studied.
Aquatic Ecology
Basically the opposite of terrestrial ecology, aquatic ecology deals with the study of the ecosystems
found in bodies of water, be it the marine, freshwater, or the estuarine .Aquatic ecology focuses on
the interactions among living organisms in a particular aquatic habitat which can directly affect various
factors in the ecosystem. Such factors include competition for food and predation, temperature, nutrient
concentration, and oxygen demand.
studies the various factors that affect population size, density, dispersion modes, and growth rate and
mortality rate.
Behavioral Ecology
The next branch of ecology, behavioral ecology, integrates the study of the interaction between
survival value to the behavior of organisms and their offspring. Interestingly, it somehow related to
evolutionary as it examines how an organism changes its behavior to ensure survival and perpetuation. At
present, this branch of ecology attempts to find the link between an animal’s behavior to its environmental
adaptation and reproductive success.
Applied Ecology
Bringing together all the concepts and principles of ecology, applied ecology aims to apply these
significant knowledge, findings, and technological advances to understand real world situations
and to address practical human problems. Applied ecology includes applications like management of
wildlife and natural resources, epidemiology, and even natural disaster risk reduction and management.
The scope of applied ecology is huge and encompasses the fields of biotechnology, ecology, to study how
anthropogenic activities affect not only micro-systems but the biosphere as well.
Like other natural sciences, environmental science is a science that gathers knowledge about the natural
world. The methods of science include careful observation, record keeping, logical and mathematical
reasoning, experimentation, and submitting conclusions to the scrutiny of others.
WEEK2: ECOSYSTEM Sub-Topic: Biotic, Abiotic Components of an Ecosystem,
Limiting Factors and Tolerance Ecologic Niche, Homeostasis in the Ecosystem
and Types of Ecosystem
Biotic Components
The live component of an ecosystem comprises plants, animals, and microorganisms (Bacteria and Fungi).
They carry out different functions and Ecologists have carry traditionally divided organisms 'roles in
ecosystems into three broad categories: producers, consumers, and decomposers.
Producers are organisms that are able to use sources of energy to make complex, organic molecules from
the simple inorganic substances in their environment. In nearly all systems, energy is supplied by the sun,
and organisms such as plants, algae, and tiny aquatic organisms called phytoplankton use light energy to
carry on photosynthesis. Since producers are the only organisms in an ecosystem that can trap energy and
make new organic material from inorganic material, all other organ-isms rely on producers as a source of
food, either directly or indirectly. Consumers are organisms that require organic matter as a source of food.
They consume organic matter to provide themselves with energy and the organic molecules necessary to
build their own bodies. Ari important part of their role is the process of respiration in which they break down
organic matter to inorganic matter. However, consumers can be further subdivided into categories based on
the kinds of things they eat and the way they obtain food.
animal they can capture and kill. In addition, many animals, called omnivores, include both plants and
animals in their diet. Even animals that are considered to be carnivores (foxes, bears) regularly include large
amounts of plant material in their diets. Conversely, animals often thought of as herbivores (mice, squirrels,
and seed- eating birds) regularly consume animals as a source of food. Parasites are also consumers that
have a special way of obtaining their food. Decomposers are organisms that use nonliving organic matter as
a source of energy and raw materials to build their bodies. Whenever an organism sheds a part of itself,
excretes waste products, or dies, it provides a source of food for decomposers. Since decomposers carry on
respiration, they are extremely important in recycling matter by converting organic matter to inorganic
material. Many small animals, fungi, and bacteria fill this niche.
Keystone Species
Ecosystems typically consist of many different species interacting with each other and their physical
surroundings. However, some species have more central roles than others. In recognition of this idea,
ecologists have developed the concept of keystone species
A keystone species is one that has a critical role to play in the maintenance of specific ecosystems. In prairie
ecosystems, grazing animals are extremely important in maintaining the mix of species typical of grassland.
Without the many influences of the grazers, the nature of the prairie changes. The relationship among sea
urchins, sea otters, and kelp forests suggests that sea otters are a keystone species. Sea otters eat sea
urchins, which eat kelp. A reduction in the number of otters results in an increase in the number of sea
urchins. Increased numbers of sea urchins lead to heavy grazing of the kelp by sea urchins. When the
amount of kelp severely reduced, fish and many other animals that Iive within the kelp beds lose their habitat
and biodiversity is significantly reduced.
Abiotic Components
The physical factors of the environment (which are nonliving) have a major influence on the life of
organisms.
The abiotic components are of two types. They are:
1. Climatic factors consist of Temperature, rainfall and snow, wind, light, humidity etc. The climate of an area
is the result of several factors such as latitude, elevation, nearness to the sea, and monsoon activities and
ocean currents. Temperature influences the rates of biochemical reactions in plants, with the reaction rates
approximately doubling with every 10°C increase. Plant species require a range of temperature to survive.
Below a minimum temperature they are inactive, and above a maximum temperature biochemical reactions
stop. Normally in many plants growth is possible above 6°C. In areas with extremes of temperature, such as
the tundra and tropical deserts the plants have mechanisms to adapt to such conditions. Light levels decide
the magnitude of photosynthesis reactions. Different plants have their characteristic light requirements in
respect of light intensity, duration and wavelength. Some plants, termed heliphytes, require high levels,
whereas sciophytes can grow in shady, low light conditions. Water is an essential factor for biochemical
plant processes, including photosynthesis. Plants growing on lands obtain their water requirements from the
soil through their roots by the osmosis process. Plants called Hydrophytes grow in fresh water and they
cannot withstand drought. Xerophytes survive long periods of drought, and halophytes are able to survive in
saline water. Mesophytes require moderate conditions (neither waterlogged nor drought) and are found
mainly in temperate areas.
2. Edaphic factors or soil factors are pH, mineral and organic matter in soil and texture of soil. Soil is the
major source of nutrients and moisture in almost all the land ecosystems. Soil is formed when a rock
weathers .The rocks brake down into a collection of different inorganic or mineral particles. The climate
influences the type and rate of the weathering of the rocks as well as the nature of the vegetation growing on
it. Nutrients are recycled in the soil by the plants and animals in their life cycles of growth, death and
decomposition. Thus, humus material essential to soil fertility is produced. Soil mineral matter is derived
from the weathering of rock material. These consist of two types; stable primary materials like quartz and
various secondary materials like clays and oxides of Al and Fe.
Soil texture is the different size range of mineral particles varying from fine clay to coarse gravel. The varying
percentages of each size range produce soils with different characteristics. Soil organic matter is called
humus that is formed by the decomposition of plant and animal matter. The rate of decay depends upon the
nature of the material and the climate. Soil organisms carry out following three main groups of processes.
Decomposition of organic material: such as plant and animal parts by bacteria, fungi, actinomycetes and
Earthworms. Bacteria and fungi also breakdown soil mineral matter generating nutrients.
A limiting factor is anything that constrains a population's size and slows or stops it from growing. Some
examples of limiting factors are biotic, like food, mates, and competition with other organisms for resources.
Tolerance ranges for the abiotic environmental conditions.
An ecological niche is the role and position a species has in its environment; how it meets its needs for food
and shelter, how it survives, and how it reproduces. A species' niche includes all of its interactions with the
biotic and abiotic factors of its environment.
A forest ecosystem consists of several plants, animals and microorganisms that live in coordination with the
abiotic factors of the environment. Forests help in maintaining the temperature of the earth and are the major
carbon sink.
Grassland Ecosystem
In a grassland ecosystem, the vegetation is dominated by grasses and herbs. Temperate grasslands,
savanna grasslands are some of the examples of grassland ecosystems.
Tundra Ecosystem
Tundra ecosystems are devoid of trees and are found in cold climates or where rainfall is scarce. These
are covered with snow for most of the year. The ecosystem in the Arctic or mountain tops is tundra type.
Desert Ecosystem
Deserts are found throughout the world. These are regions with very little rainfall. The days are hot and the
nights are cold.
Aquatic Ecosystem
Aquatic ecosystems are ecosystems present in a body of water. These can be further divided into two types,
namely:
1. Freshwater Ecosystem
2. Marine Ecosystem
The freshwater ecosystem is an aquatic ecosystem that includes lakes, ponds, rivers, streams and wetlands.
These have no salt content in contrast with the marine ecosystem
Marine Ecosystem
The marine ecosystem includes seas and oceans. These have a more substantial salt content and greater
biodiversity in comparison to the freshwater ecosystem.
WEEK3: Energy Flow in the Ecosystem, Tropic Levels, Food Chain and
Food Web, Pyramids of Energy and Biomass (Ecological Pyramid), the
Laws of Thermodynamics: Materials, Cycle within Ecosystem
Energy Flow through Ecosystems
An ecosystem is a stable, self-regulating unit. This does not mean that an ecosystem is unchanging the
organisms within it are growing reproducing, dying and decaying. In addition, an ecosystem must have a
continuous input of energy to retain its stability. The only significant source of energy for most ecosystems
is sunlight. Producers are the only organisms that are capable of trapping solar energy through the
process of photosynthesis and making it available to the ecosystem. The energy is stored in the form of
chemical bonds in large organic molecules such as carbohydrates (sugars, starches), fats, and proteins.
The energy stored in the molecules of producers is transferred to other organisms when the producers
are eaten.
Trophic Levels
Each step in the flow of energy through an ecosystem is known as a trophic level. Producers (plants,
algae, and phytoplankton) constitute the first trophic level, and first trophic level, and Herbivore’s
constitute the second trophic level. Carnivores that eat herbivores are the third trophic level, and
carnivores at eat other carnivores are the fourth trophic level. Omnivores, parasites, and scavengers
occupy different trophic levels, depending on what they happen to be eating at the time.
Energy, chemical elements, and some compounds are transferred from creature to creature along food chains.
The more complex linkages are called food webs.
Food web is a connection of multiple food chains. Food chain follows a single path whereas food web
follows multiple paths.
Ecologists group the organisms in a food web into trophic levels. A trophic level (from the Greek word trephein)
meaning to nourish, thus the "nourishing level") consists of all organisms in a food web that are the same number of
feeding levels away from the original energy source. Then original source of energy in most ecosystems is the sun. In
other cases, it is the energy in certain inorganic compounds. Green plants, algae, and certain bacteria produce
sugars through the process of photosynthesis, using only energy from the sun and carbon dioxide (CO2) from the air.
They are called autotrophs, from the words auto (self) and trephein (to nourish), thus "self- nourishing," and are
grouped into the first trophic level.
Trophic level, step in a nutritive series, or food chain, of an ecosystem. The organisms of a chain are classified into
these levels on the basis of their feeding behaviour. The first and lowest level contains the producers, green plants.
The plants or their products are consumed by the second-level organisms—the herbivores, or plant eaters. At the
third level, primary carnivores, or meat eaters, eat the herbivores; and at the fourth level, secondary carnivores eat
the primary carnivores. These categories are not strictly defined, as many organisms feed on several trophic levels;
for example, some carnivores also consume plant materials or carrion and are called omnivores, and some
herbivores occasionally consume animal matter. A separate trophic level, the decomposers or transformers, consists
of organisms such as bacteria and fungi that break down dead organisms and waste materials into nutrients usable
by the producers.
Energy Pyramid
An energy pyramid (sometimes called a trophic pyramid or an ecological pyramid) is a graphical representation,
showing the flow of energy at each trophic level in an ecosystem.
A pyramid of energy shows how much energy is retained in the form of new biomass at each trophic level, while a
pyramid of biomass shows how much biomass (the amount of living or organic matter present in an organism) is
present in the organisms.
The width of each bar represents the units of energy available within each trophic level; the height is always the
same. The flow of energy moves through the layers of the energy pyramid from the bottom-up, and is gradually
reduced as energy is used up by the organisms at each level
The base of the energy pyramid indicates the energy available within primary producers. Primary producers, also
known as autotrophs, are organisms which create their own food by taking their energy from non-living sources of
energy. In most cases, these are photosynthesizing plants, which use energy from the sun to create their own
nutrition in the form of simple sugars, although there are exceptions such as deep sea organisms, which use
chemical energy from hydrothermal vents. In this description we will focus on ecosystems that take energy from the
sun.
All other levels in the energy pyramid consist of heterotrophs – organisms that obtain their nutrition from organic
carbon, usually in the form of other plants and animals.
The second trophic level consists of primary consumers. These are the herbivores that feed solely on primary
producers. The third and fourth levels are made up of secondary consumers and tertiary consumers. These are
carnivores and omnivores, which can feed on any of the lower levels, although mainly consume organisms from the
trophic level directly beneath them. The top layer of the energy pyramid contains apex predators. These are mostly
carnivorous animals that have no natural predators.
Ecological Pyramid
The pyramid shape is used to represent the flow of energy because of the way that energy is used up and
lost throughout the system.
Rudolph Clausius and appeared in English in 1868. A common example of entropy is that of ice melting
in water. The resulting change from formed to free, from ordered to disordered increases the entropy.
● 1st law of thermodynamics in Ecosystem
Energy from Sun to Plant, Chlorophyll of green plants traps the light energy from sun and produce food
with the help of water, CO2 and minerals.
Energy users Producers– Green plants use light energy (sunlight) to produce food (chemical energy).
Primary consumers– Feed on herbivores and get energy from plants (Carnivores). Secondary
consumers– Feed on primary consumers and get energy form them. Tertiary consumers- Feed on
secondary consumers and get energy. Decomposers- Break down dead or decaying organism
(decomposition) and get energy.
Food chain or food web support the 1st law of thermodynamics
Energy Recycling Plants or Producers 1st tropic level Energy Sun The energy house Energy Consumers
2nd tropic level Decomposers 3rd tropic level E n e r g y Energy Soil, Air, Water with matter Heat
● 2nd Law of Thermodynamics
In the path of energy transformation some energy loss in the form of heat and the entropy increases.
The Path Way of Energy Loss Not all food consumed by heterotrophs (consumers) is transformed into
biomass. At each tropic level about 90% of energy is loss to perform metabolic activities. Entropy
increases.
WEEK4: Biogeochemical Cycles, The Hydrologic Cycle, The Carbon-
Oxygen Cycle, The Nitrogen Cycle, The Phosphorus Cycle and The
Sulfur Cycle
Biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circulated. The
term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical
aspects of each cycle.
Elements within biogeochemical cycles flow in various forms from the nonliving (abiotic) components of the biosphere
to the living (biotic) components and back. In order for the living components of a major ecosystem (e., a lake or a
forest) to survive, all the chemical elements that make up living cells must be recycled continuously. Each
biogeochemical cycle can be considered as having a reservoir (nutrient) pool—a larger, slow-moving, usually abiotic
portion—and an exchange (cycling) pool—a smaller but more-active portion concerned with the rapid exchange
between the biotic and abiotic aspects of an ecosystem.
All matter is made up of atoms. These atoms are cycled between the living and non-living portions of an ecosystem.
The activities involved in the cycling of atoms include biological, geological, and chemical processes. Therefore,
these nutrient cycles are often called biogeochemical cycles.
Some atoms are more common in living things than are others. Carbon, nitrogen, oxygen, hydrogen, and phosphorus
are found in important organic molecules such as proteins, DNA, carbohydrates, and fats, which are found in all kinds
of living things. Organic molecules contain large numbers of carbon atoms attached to one another. These organic
molecules are initially manufactured from inorganic molecules by the activities of producers and are transferred from
one living organism to another in food chains. The processes of respiration and decay ultimately break down the
complex organic molecules of organisms and convert them to simpler, inorganic constituents that are returned to the
abiotic environment. In this section, we will look at the flow of six kinds of atoms within communities and between the
biotic and abiotic portions of an ecosystem: water, carbon, oxygen, nitrogen, phosphorus and Sulphur.
Water Cycle
The water cycle, also known as the hydrologic cycle or the HO cycle, describes the continuous movement of water
on, above and below the surface of the Earth. The mass water on Earth remains fairly constant over time but the
partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric is variable
depending on a wide range of climatic. The water moves from one reservoir to another, such as from river to ocean,
or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation,
infiltration, runoff, and subsurface flow. In so doing, the water goes through different phases: liquid, solid (ice), and
gas (vapor). The water cycle involves the exchange of energy, which leads to temperature changes. For instance,
when water evaporates, it lakes up energy from its surroundings and cools the environment. When it condenses, it
releases energy and warms the environment. These heat exchanges influence climate. The evaporative phase of the
cycle purifies water which then replenishes the land with freshwater. The flow of liquid water and ice transports
minerals across the globe. It is also involved in reshaping the geological features of the Earth, through processes
including erosion and sedimentation.
The water cycle is also essential for the maintenance of most life and ecosystems on the planet. The Sun, which
drives the water cycle, heats water in oceans and seas. Water evaporates as water vapor into the air. lce and snow
can sublimate directly into water vapor. Evapotranspiration is water transpired from plants and evaporated from the
soil. Rising air currents take the vapor up into the atmosphere where cooler temperatures cause it to condense into
clouds. Air currents move water vapor around the globe; cloud particles collide, grow, and fall out of the upper
atmospheric layers as precipitation. Some precipitation fails as snow or hail, sleet, and can accumulate as ice caps
and glaciers, which can store frozen water for thousands of years. Most water falls back into the oceans or onto land
as rain, where the water flows over the ground as surface. A portion of runoff enters rivers in valleys in the landscape,
with stream flow moving water towards the oceans. Runoff and water emerging from the ground (groundwater) may
be stored as freshwater in lakes. Not all runoff flows into rivers, much of it soaks into the ground as infiltration. Some
water infiltrates deep into the ground and replenishes aquifers, which can store freshwater for long periods of time.
Some infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as
groundwater discharge. Some groundwater finds openings in the land surface and comes out as freshwater springs.
In river valleys and flood-plains there is often continuous water exchange between surface water and ground water in
the hyporheic zone. Over time, the water returns to the ocean, to continue the water cycle.
Carbon Cycle
All living things are composed of organic molecules that contain atoms of the element that carbon. The carbon cycle
includes the processes and pathways involved in capturing inorganic carbon-containing molecules, converting them
into organic molecules that are used by organisms, and the ultimate release of inorganic carbon molecules back to
the abiotic environment.
however, nitrogen is made available to plants, which in turn ultimately sustain all animal life. The steps, which are not
altogether sequential, fall into the following classifications: nitrogen fixation, nitrogen assimilation, ammonification,
nitrification, and denitrification.
The phosphorus cycle
Phosphorus is a chemical element found on Earth in numerous compound forms, such as the phosphate ion (PO43-),
located in water, soil and sediments. The quantities of phosphorus in soil are generally small, and this often limits
plant growth. That is why people often apply phosphate fertilizers on farmland. Animals absorb phosphates by eating
plants or plant-eating animals. The role of phosphorus in animals and plants
Phosphorus is an essential nutrient for animals and plants. It plays a critical role in cell development and is a key
component of molecules that store energy, such as ATP (adenosine triphosphate), DNA and lipids (fats and oils).
Insufficient phosphorus in the soil can result in a decreased crop yield.
The phosphorus cycle
Phosphorus moves in a cycle through rocks, water, soil and sediments and organisms.
Here are the key steps of the phosphorus cycle
Over time, rain and weathering cause rocks to release phosphate ions and other minerals. This inorganic phosphate
is then distributed in soils and water.
Plants take up inorganic phosphate from the soil. The plants may then be consumed by animals. Once in the plant or
animal, the phosphate is incorporated into organic molecules such as DNA. When the plant or animal dies, it decays,
and the organic phosphate is returned to the soil.
Within the soil, organic forms of phosphate can be made available to plants by bacteria that break down organic
matter to inorganic forms of phosphorus. This process is known as mineralisation.
Phosphorus in soil can end up in waterways and eventually oceans. Once there, it can be incorporated into
sediments over time.
Sulfur Cycle
Sulfur is released from geologic sources through the weathering of rocks. Once sulfur is exposed to the air, i+
combines with oxygen, and becomes sulfate SO4Plants and microbes assimilate sulfate and convert it into organic
forms. As animals consume plants, the sulfur is moved through the food chain and released when organisms die and
decompose. Some bacteria - for example Proteus, Campylobacter, Pseudomonas and Salmonella - have the ability
to reduce sulfur, but can also use oxygen and other terminal electron. Others, such as Desulfuromonas, use only
sulfur. These bacteria get their energy by reducing elemental sulfur to hydrogen sulfide. They may combine this
reaction with the oxidation of acetate, succinate, or other compounds. Organic The most well-known sulfur reducing
bacteria are those in the domain Archea, which are some of the oldest are forms of life on Earth. They are often
extremophiles, living in hot springs and thermal vents where other organisms cannot live. Lots of bacteria reduce
small amounts of sulfates to synthesize sulfur-containing cell components; this is known as assimilatory sulfate
reduction. By contrast, the sulfate- reducing bacteria considered here reduce sulfate in large amounts to obtain
energy and expel the resulting sulfide as waste. This process is known as dissimilatory sulfate known as reduction. In
a sense, they breathe sulfate. Dissimilatory sulfate Sulfur metabolic pathways for bacteria have important medical
implications. For example, Mycobacterium tuberculosis (the bacteria causings tuberculosis) and Mycobacteriumn
leprae (which causes leoprosy) both utilize sulfur, so the sulfur pathway is a target of drug development to control
these bacteria.
1. Mineralization of organic sulfur into inorganic forms, such as hydrogen (HS), elemental sulfur, as
Well as sulfide minerals.
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GEE1 WEEK1-17 - NOTES
Course: Bachelor in Secondary Education (BSED 4101- S)
544 Documents
Students shared 544 documents in this course
University: Bestlink College of the Philippines
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WEEK1 : SCIENTIFIC METHOD, ENVIRONMENTAL EDICATION: ITS
DEFINITION AND IMPORTANCE ECOLOGY, AND ENVIRONMENTAL EARTH
SCIENCE
What is ecology? Ecology, the study of relationships between organisms and the environment, has been
a focus for human study for as long as we have existed as a species. Our survival has depended upon
how well we could observe variations in the environment and predict the responses of organisms to those
variations. The earliest hunters and gatherers had to know the habits of their animal prey and where to
find food plants. Later, agriculturists had to be aware of variations in weather and soils and of how such
variation might affect crops and livestock.
Brief History of
Environmental
Science
There are three
"revolutions" that play
a significant role in the
development of
environmental
science. These are
then Agricultural
Revolution, Industrial-
Medical Revolution
and Information-
Globalization
Revolution.
Agricultural revolution
can be traced back
10,000 years ago
where nomadic
lifestyles of hunters moved gradually to farming of domesticated plants and animals. This lifestyle shift
resulted to a negative effect on the environment
Landscapes undergone intense alterations and people lived longer and reproduce more resulting to an
increase in population. During this time, there was limited awareness on environmental threats.
Deforestation was unregulated causing soil erosion which was believed to have contributed to the
downfall1 of many civilizations. The mid-1700s to mid-1800s was the beginning of Industrial-Medical
Revolution. It is an Age of enlightenment, as Science continues to progress and develop. Development of
these new technologies led to pollution and other environmentally related problems. Nuclear weapons,
DDT and other pesticides and synthetic problems. Materials like plastics were produced during this time.
Population increased causing famine because food supply time. Does not increase. People started to
become more aware of the things happening around them. In fact, Ben Franklin fought against pollution in
Philadelphia as industries continue to pollute the air. In 1854, Dr. John Snow first as industries recognized
a pattern in an epidemic and linked it to the environment. He found out that contaminated water from one
pump led to the spread of cholera. Concern about the environment in the US was voiced only in the mid-
1800s by people like Henry David Thoreau.
The Information-Globalization Revolution started way back in 1950 and flourish during the 1970's. In spite
of the growing awareness on environmental threats, people growing continue to develop products and
methods that have detrimental effects to the environment. Computers were developed to gain access to
more information in a global Scale through the use of the internet. Phones and remote- sensing satellites
were invented. These developments do not only affect our personal lives, our culture and economy but it
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