Ecosystem: Everything Is Connected

ECOSYSTEM Everything Is Connected

What is an Ecosystem? Refers to an interacting group of natural elements and the organism in a given environment  A unit interrelationships between and among living things and non-living things  Possesses both living (biotic) and non-living (abiotic) components of the environment 

Ecosystems Are Connected People often think of ecosystems as isolated from each other, but ecosystems do not have clear boundaries. Things move from one ecosystem into another. Soil washes from a mountain into a lake, birds migrate from Michigan to Mexico, and pollen blows from a forest into a field. Living things respond and adapt to non-living conditions in their environment to maintain homoestasis, or their steady state condition

The Components of an Ecosystem BIOTIC AND ABIOTIC FACTORS

BIOTIC FACTORS 

These are the living and once living parts of an ecosystem, including all of the plants and animals.

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Biotic factors include dead organisms, dead parts of organisms, such as leaves, and the organisms’ waste products.

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Classified as how organisms consume raw materials for energy:

Producers – an organism that makes its own food. Producers are also called autotrophs, self-feeders Consumers – organisms that get their energy by eating other organisms. Consumers are also called heterotrophs, otherfeeders.

The Diversity of Living Things

Types of Producers A. Photosynthetic Organisms 

a plant uses sunlight to make sugar molecules by a process called photosynthesis

Types of Producers B. Chemosynthetic Organisms 

Obtain energy by oxidizing inorganic compounds such ammonia, nitrates, and sulfides and use this energy to synthesize organic compounds

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Have been found supporting communities in some caves and also at hydrothermal vents along deep sea oceanic ridges • • •

Bacteria, such as those in the picture, live in some of these organisms and use hydrogen sulphide to make their own food. Hydrogen sulfide is present in the hot water that escapes from the cracks in the ocean floor. Therefore, the bacteria are producers that can make food without sunlight. These bacteria are eaten by the other underwater organisms and thus support a thriving ecosystem.

Types of Consumers A. Herbivores 

Consumers that eat only producers are called herbivores, or plant eaters.

B. Carnivores 

Consumers, such as lions and hawks, that eat only other consumers are called carnivores, or flesh eaters.

C. Omnivores 

Consumers that eat both plants and animals are called omnivores, or eaters of all.

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Scavengers are omnivores that feed on the dead remains of plants and animals that have recently begun to decompose.

D. Decomposers 

Consumers, such as bacteria and fungi, that use their digestive secretions to chemically breakdown their dead organic matter including animal wastes in the external environment

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Returns nutrients to soil, air and water

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Decomposers produce detritus

Detritus is a term that refers to organic remains in the water and soil that are in the final stage of decomposition

ABIOTIC FACTORS 

These are the non-living parts of the ecosystem

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Abiotic factors include: 

Sunlight

 Water  Temperature

 Wind  Atmospheric  Rocks

Gases

and soil

 Chemical  Periodic

substances

disturbances

A. Sunlight 

Primary source of energy in nearly all ecosystems

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Energy used by plants during the process of photosynthesis

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In aquatic environments, the availability of sunlight has a significant effect on the growth and distribution of algae

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Because water itself and microorganisms in it absorb light and keep it penetrating very far, most photosynthesis occurs near the surface of the water

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In terrestrial environment, light is not often the most important factor limiting plant growth

Photoperiodism 

The response of plants to changes in the length of day and night

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Organized into three categories: long day plants, short day plants, and day neutral plants

Long Day Plants 

Plants that begin the flowering process before the summer solstice, June 12, when the lengthening days reach some critical length

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Examples are radish, lettuce, potatoes, and spinach

Short Day Plants 

Plants that begin the flowering process after the summer solstice, December 21

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Examples are strawberries, poinsettia, chrysanthemums, and primrose

Day Neutral Plants 

Plants which appear to be in different cycles of night and day

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May flower continuously or respond to other stimuli

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Examples are sunflower, cucumber and dandelions

Nocturnal Animals 

Animals that are active only at night

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They tend to have keen eyesight and excellent hearing

Diurnal Animals 

Animals that demonstrate activity during the day

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They tend to have poor eyesight and hearing compared to nocturnal animals

Crepuscular Animals 

Animals that are active during the twilight hours, at and dusk

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Animals take advantage of the twilight to feed, seek out water and engage in other behaviors because they know that predators are not as active in twilight

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Visibility is also challenging at dawn and dusk, making it easier for animals to hide from potential threats

B. Water 

The universal solvent and the basis of all life on our planet

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An odorless, tasteless substance that covers more than 70% of the earth’s surface Global Water Distribution •

Although 71 percent of the Earth’s surface is covered with water, nearly 97 percent of Earth’s water is salt water in oceans and seas.

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Of the fresh water on Earth, about 77 percent is frozen in glaciers and polar icecaps. Only a small percentage of the water on Earth is liquid fresh water that humans can use.

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Water is the primary agent for the chemical and mechanical breakdown of rocks called weathering to form loose rock fragments (regolith) and soil

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By the process of erosion, water sculpts the surface of the earth as precipitation falls on the land and makes it way from rivers to the sea

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Waves from ocean storms can erode coastlines to give rise to a variety of spectacular landforms.

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Aquatic organisms have a seemingly unlimited supply of water, but they face problems of water balance if their solute concentration does not match that of their surroundings

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For terrestrial organisms, the main water problem is the threat of drying out. Many land species have water-tight coverings that reduce water loss.

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According to water requirements, plants are grouped into: 

Hydrophytes – plants that actually live in water

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Mesophytes – plants that need moderate amount of water

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Epiphytes – plants that get their water from the air

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Xerophytes – plants that grow under dry conditions

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Halophytes – plants that can live in salty water

Hydrophytes (water lily)

Mesophytes (rose)

Epiphytes (orchids)

Xerophytes

Halophytes

(cactus)

(mangrove)

C. Temperature 

Describe as the measure of a hotness or coldness of the body, substance or the environment

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Temperature of air depends on the temperature of the temperature of the surface below

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Temperature remains lower on surfaces like snow and ice compared areas of forests and soil

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Temperature decreased as you move higher in the mountain

Environmental temperature is an important abiotic factor because of its effect in metabolism 

Few organisms can maintain sufficiently active metabolism at temperatures close to 0°C

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Temperatures above 50°C destroy the enzymes of most organisms

Effects of Temperature in Plants 

Sometimes, temperatures are used in connection with day length to manipulate the flowering of plants

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Chrysanthemums will flower for a longer period of time if daylight temperatures are 50°F

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The Christmas cactus forms flowers as a result of short days and low temperature

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Daffodils are forced to flower by putting bulbs in cold storage in October at 35 to 40°F. The cold temperature allows bulb to mature. The bulbs are transferred to greenhouse in midwinter where growth begins. The flowers are then ready for cutting in 3 to 4 weeks

Temperature Regulation in Animals 1.

Cold-blooded Animals (Poikilotherms) 

Animal whose internal temperature varies along with that of the ambient environmental temperatures

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Examples are reptiles, fishes, and amphibians

2. Warm-blooded Animals (Homeotherms) 

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Animal whose members keep their body temperature at a roughly constant levels regardless of the ambient temperature Has an ability to cool down or produce more heat by regulating their metabolic rates Examples are mammals and birds

Corrective Mechanisms in Temperature Control 

Increased sweating aimed to reduce temperature of organisms.

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Vasodilation is a corrective response where the blood vessels close to the skin surface become more dilated, meaning there is a larger surface area for heat to be lost from the blood vessels carrying over heated blood.

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Vasoconstriction occurs when the temperatures in an organism drop. The blood vessels become constricted so that minimal heat loss occurs.

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The hairs on your body has a corrective response where hairs “stands on end”, and trap a layer of air between the hair and the skin. This insulation of warmer air next to the skin reduces heat lost, while a thin layer of insulation would increase heat loss.

Effect of Temperature in Plants Thermoperiod refers to daily temperature change  Plants produce maximum growth when exposed to a day temperature 10 to 15°F higher than the night temperature  High temperatures cause increased respiration (break down), sometimes above the rate of photosynthesis (build up) which means the energy are being used rapidly than it is being produced  Low temperatures can also result in poor growth, photosynthesis is slowed down and results in lower yields  Buds of many plants require exposure to a certain number of days before a critical temperature (chilling hours) before they resume growth in spring  During dormancy, buds can withstand very low temperatures but after the rest period, buds are more susceptible to weather conditions and can be damaged easily by frost 

D. Wind 

Winds have great effect on weather and climate

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Wind constantly wears down rocks and scoops out canyons, it carries away sand and soil by the process of soil erosion and eventually results to soil formation

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Some organisms, such as bacteria, protists and many insects that live on snow-covered mountain peaks depend on the nutrients blown on them by winds

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Many plants depend on wind to disperse their pollen and seeds

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Local wind damage often creates opening in forest, contributing patchiness in ecosystem

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Wind also increases an organism’s rate of water loss by evaporation. The consequent increase in evaporative cooling can be advantageous in summer but can cause dangerous wind chill in the winter.

Monsoons 

These are large-scale seasonal wind

Southwest Monsoon (Habagat) 

Blows during the months of June to October each year

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Subjected to abundant rainfall and extensive cloud development at the western sections of the country

Northeast Monsoon (Amihan) Blows during the months of November to February each year  Subjected to abundant rainfall and extensive cloud development at the eastern sections of the country 

The Philippines have a year-round humid, tropical climate.

E. Atmospheric Gases GASES NAME

PERCENT VOLUME

Nitrogen

78.08 %

Oxygen

20.95 %

Water

0 to 4 %

Argon

0.93 %

Carbon Dioxide

0.360 %

Neon

0.0018 %

Helium

0.0005 %

Methane

0.00017 %

Hydrogen

0.00005 %

Nitrous oxide

0.00003 %

Ozone

0.000004 %

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Nitrogen, oxygen, water vapor, carbon dioxide, methane, nitrous oxide and ozone are extremely important to the health of the Earth’s biosphere

 Nitrogen 

Removed from the atmosphere and deposited at the Earth’s surface mainly by specialized nitrogen-fixing bacteria and by way of lightning through precipitation

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Addition of nitrogen to the earth’s surface soils and various bodies of water supplies much needed nutrition for plant growth

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Returns to the atmosphere primarily through biomass combustion and denitrification

 Oxygen 

Exchanged between the atmosphere and life through the process of photosynthesis and respiration

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In respiration, oxygen is combined with glucose to chemically release energy for metabolism

 Water Vapor 

Redistributes heat energy on the Earth through latent heat energy exchange

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The condensation of water vapour creates precipitation that falls to the Earth’s surface providing needed fresh water for plants and animals

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Helps warm the Earth’s atmosphere through the greenhouse effect

 Carbon dioxide 

Increased by over 35% in the last three hundred years

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Increase is primarily due to human induced burning from fossil fuels, deforestation, and other forms of land-use change

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Human-caused increase in its concentration in the atmosphere has strengthened the green house effect and has definitely contributed to global warming over the last 100 years

 Methane 

A very strong greenhouse gas, since 1750, it increased by more than 150%

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Primary sources for the additional methane in the atmosphere are: 

Rice cultivation

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Domestic grazing animals

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Termites

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Landfills

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Coal mining

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Oil and gas extraction

 Ozone 

Stratospheric ozone provides an important service to life on Earth as it absorbs harmful ultraviolet radiation

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At the surface of the Earth, however, ozone is a human-made air pollutant that at certain concentrations may affect human health.

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Ozone forms from the reaction of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of heat and sunlight.

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As ozone concentrations in the atmosphere increase, greater numbers of people may experience harmful health effects of ozone on the lungs.

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Exposure to ozone may also accelerate the natural aging process.

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In recent years, levels of stratospheric ozone have been decreasing due to the build up of chlorofluorocarbons (CFCs)

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Satellite measurements have indicated that the ozone had a 3% decrease in stratospheric ozone

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CFCs were being used in refrigerators, air-conditioners, aerosol spray containers, and many other consumer products.

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Since late 1970, scientists have noticed the development of severe holes in the ozone layer over Antarctica

F. Rocks and Soil 

It sustains the growth of all plants and animals and forms part of the biosphere

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Formation of soil is attributed to combined effect of the physical, chemical, and biotic forces acting on organic and weathered rock fragments resulting to soil with porous fabric that contains water and air

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The physical and chemical composition of rocks and soil limit the distribution of plants and of animals that feed on the vegetation.

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In streams and rivers, the composition of the substrate can affect water chemistry, which in turn influences the resident plants and animals

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In marine environments, the structure of underlying substrates determines the types of organisms that can attach or burrow in those habitats

Classification of Soil 

Texture is determined by the minerals, water and air that composed the soil

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The minerals present determines the classification of the soil

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The soil particles present in soil vary by size and characteristics

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Texture along with the organic content and pH, determine how well a plant will grow without any interference

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Soil is classified according to particle size as clay soil, silt soil and sandy soil

Clay Soil (<0.002 mm) 

Made up approximately 0 to 45% sand, 0 to 45% silt and 50 to 100% clay

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Sticky and feels almost plastic-like when it is wet

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Holds water and nutrients well

Silt Soil (0.002 – 0.05 mm) 

Made up approximately 25 to 50% sand, 30 to 50% silt and 10 to 30% clay

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Feels smooth and slippery when wet

Sandy Soil (0.05 – 2.0 mm) 

Made up approximately 80 to 100% sand, 0 to 10% silt and 0 to 10% clay

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Drains quickly after it rains, is easy to work with and warms up quickly in warm weather

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Has lower moisture and nutrient holding capacity

Soil Horizon 

O Horizon – Organic matter. Litter layer of plant residues in relatively undecomposed from

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A Horizon – Surface soil. Layer of mineral soil with most organic matter accumulation and soil life. This layer is depleted of iron, clay, aluminum, organic compounds, and other soluble constituents

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When eluviation is pronounced, a lighter colored “E” subsurface soil horizon is apparent at the base of the “A” horizon.

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B – Subsoil. This layer accumulates iron, clay, aluminium, and organic compounds, a process referred to as illiviation

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C – Parent rock. Layer of large unbroken rocks. This may accumulate the more soluble compounds. Humus is a decomposed organic material

Types of Soil   

Classified according to nature of parent material, climate and vegetation The most general category of the Soil Classification System recognizes eleven distinct soil orders: Oxisols, ardisols, mollisols, alfisols, ultisols, spodosols, entisols, inceptsols, vertisols, histosols, andisols

G. Chemical Substances  Acids 

Some microorganisms would require acidic conditions in order to survive, they are categorized as acidophiles

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Plants would require some acids such as abcisic acid for growth and development that plays an important role in integrating various stress signals and controlling downstream stress responses

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Some plants that grow best in acid soils are azaleas, ericas, ferns and many protea species

 Bases 

Various biological activities such as ammonification or sulfate reduction can lead to transient alkalinity in microhabitats that is widespread feature of heterogeneous environment such as soils and the highly alkaline Ca2+ dominated ground waters that are present in various geological locations have paved the way for the existence of microorganisms that are categorized as alkaliphiles

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Some plants grow best in alkaline soils with pH above 7 such as Lucerne and many xerophytes

 Salts 

Molten salts and solutions containing dissolved salts are called electrolytes

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Plants that have adapted to live in salty environments are called halophytes

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Salt draws water out of the roots of most plants, slowly drying them out but some halophytes have ways to get rid of excess salt

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Mangroves take in salts from saltwater from their roots, the salt is carried in the tree’s sap up to old leaves, which are then shed or to living leaves which have glands that excrete salt

 Carbohydrates 

Also termed as saccharides, are divided into four chemical groupings: monosaccharide, disaccharides, oligosaccharides, polysaccharides

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Monosaccharide and disaccharides are smaller carbohydrates which commonly referred to as sugar

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Polysaccharides serves as storage of energy (starch and glycogen) and as structural components (cellulose and chitin)

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Saccharides and their derivatives include many other important biomolecules that play key roles in immune system, fertilization, preventing pathogenesis, blood clotting, and development

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Carbohydrates are coming from the different plants in the form of glucose

 Proteins 

Many proteins are enzymes that catalyse the chemical reaction in metabolism

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Other proteins have structural or mechanical functions, such as proteins that form the cytoskeleton that maintain the cell shape

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Essential amino acids cannot be produced by the body and must be brought in through diet while non-essential amino acids can be made by the body

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Complete proteins are those that contain all of the essential amino acids, while incomplete proteins lack one or more of the essential amino acids

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The body needs all the essential amino acids to build or repair tissues

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Soy is the only vegetable protein to be complete

 Lipids 

Are non-soluble in water and combine with carbohydrates and proteins to form majority of all the plants and animal cells

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Commonly synonymous with the word “fats” in terms of personal health, and though all fats are lipids, not all lipids are fats

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Major purposes of lipids are energy storage, cell membrane development, and serving as a component of hormones and vitamins in the body

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Lipoprotein is the medical term used to define a combination of fat and protein

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Cholesterol is a naturally occurring substance in the body and is comprised by lipids

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Cholesterol is separated in two types, high density lipoprotein (HDL) and low density lipoprotein (LDL)

 Nucleic Acids 

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Biological molecules essential for life, and include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) Each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information When a cell divides, its DNA is copied and passed from one cell generation to next generation DNA contains the “programmatic instructions for cellular activities, when organisms produce offspring, these instructions in the form of DNA are passed down RNA is involved in the synthesis of proteins, information is typically passed from DNA to RNA to the resulting proteins

H. Periodic Disturbances 

Catastrophic disturbances, such as fires, hurricanes, tornadoes, and volcanic eruptions, can devastate biological communities

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After the disturbance, the area is re-colonized by organisms or repopulated by survivors, but the structure of the community undergoes a succession of changes during the rebound

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Some disturbances, such a volcanic eruptions, are so infrequent and irregular that organisms have not acquired evolutionary adaptations to them

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Fire, although unpredictable over the short term, recurs frequently in some communities, and many plants have adapted to this periodic disturbances

Types of Natural Fires

 Surface Fires 

Usually move rapidly through an area and do not consume all organic layers

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Burn the upper litter layer and small branches that lie on or near the ground

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Moisture in organic horizons prevents ignition of the humus layer and protects the soil and inhabiting organisms from the heat

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Fast moving fires does not normally persist long enough to damage tissues underneath the thick bark of large trees

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But it will girdle the root collar of small trees and shrubs and reduce small diameter branches

 Ground Fires 

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Usually occur only during periods of protracted drought when the entire soil organic layer may dry sufficiently, but they may burn for weeks or months until precipitation and low temperature extinguish the fire or they run out of fuel Large and small trees are generally killed because of long and high temperature heat pulse generated Release considerable amounts of nutrients from burned fuels Can cause an increased chance of surface flow and erosion on slopes and leave a baked and hardened seedbed that may prevent rapid revegetation

 Crown Fires 

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Occur in forests during periods of drought and low relative humidity, particularly in areas with heavy accumulations of understory material called ladder fuels such as fallen trees, logging slash and combustible understory vegetation Tree crowns become engulfed in flames and the fire spread to nearby trees Generate tremendous heat that rises in a strong convection column, drawing in brisk surface winds that fan the flames even more Have environmental effects similar to those of ground fires

Limiting Factors and Tolerance

 Limiting Factors 

Are environmental influences that constrain the productivity of organisms, populations, or communities and thereby prevent them from achieving their full biological potential, which could be realized under optimal conditions

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Can be single elements or a group of related factors

 Law of Minimum

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States that the growth and well-being of an organism is ultimately limited by that essential resource, this is in its lowest supply relative to what is required

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The most deficient resource is therefore called the limiting factor

 Law of Tolerance

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States that for each physical factor in the environment, a minimum and maximum limit exists called tolerance limit; beyond which the organism does not thrive or survive

 Adaptation 

an inherited trait that increases an organism’s chance of survival and reproduction in a certain environment

Difference of Niche from Habitat 

Niche is more on how the organisms behave in the places where they belong, while habitat is focused on the place where each organism belongs

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Niche is more on how organisms react to their environment, while habitat is more on how their environment affects them

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The short definition of niche is how an organism makes a living in the place it belongs, while habitat is where the organism live

Difference of Niche from Habitat

Homeostasis in Ecosystem 

Refer to the optimum balance in any system, be it biological or environmental in nature

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Balance in nature simply considers the different aspect of the ecosystem which comprise of biotic and abiotic components in it

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Humans and other living entities in the ecosystem must not engage in activities that incurred accumulated wastes that will disrupt the prevailing biochemical cycles and other abiotic factors which will lead to an imbalance state of ecosystem

Types of Ecosystem 

Ecosystems differ in flora (plants), fauna (animals) and environmental conditions, but all of them support some kind of life

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Therefore it is very important to understand the features of the ecosystem before entering it and trying to make changes

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It was lack of this understanding in early days that led to the exploitation of natural habitats and extinction of many rare species, along with the distractions of some beautiful landscapes

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Human beings are known to act in manners which disrupt the natural cycles and flow of things in ecosystem that leads to major problems

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To prevent this from happening, we need to understand what type of ecosystem we are dealing with

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There are basically two types of ecosystems: terrestrial and aquatic