CHAPTER 8DYNAMIC ECOSYSTEM

ECOSYSTEM COMPONENT

BIOTIC COMPONENT

ABIOTIC ABIOTIC COMPONENTCOMPONENT

ABIOTIC COMPONENTThe non living components

of an ecosystem

pH value

Temperature Light intensity

Humidity

Water

Topography

Microclimate

pH value

• the pH value of soil and water has important effect on the types of organisms

• a drastic change in pH may kill the organisms

Temperature

• affects the physiological activities of organisms

• most of organisms cannot tolerate extremes temperatures

Light intensity

• affects the distribution and growth of organisms

• the sun is the source of energy

• some plants show adaptation to reach the light

• most animal need sunlight but some show adaptation to live in the dark

Humidity

• is the amount of water vapour in the air

• plant and animal that live in wet have special adaptation

Water

• important for living process in all organisms

• but some organisms are able to survive under condition where there is a limited supply of water such as camel and cactus

Microclimate

• Refers to local climate in a small area

• Humidity, temperature and light intensity affect the microclimates

Topography

• influence local climate and soil development

• the main factor is altitude and aspect

• higher altitude : lower atmospheric pressure and temperature so different plants growing at different altitude

• sloppy areas receive more sunlight compared to valley

•Gradient : steepness of a slope cause a faster drainage and run off the water

BIOTIC COMPONENTSThe living components

in an ecosystem

Producers Consumers

Decomposers

Producers

• mainly green plants

• manufacture complex organic food substances from raw materials

•Convert light energy → chemical energy

• affect the lives of other organisms because they start the food chain and food web

Consumers

• Obtain their energy from the other organisms they feed on

• Cannot make their own food : heterotrophs (herbivores, carnivores, omnivores, saprophytes or decomposers )

Decomposers

• break down dead organisms through the decomposition process

• the product in this process is returned to environment and will used again by green plants

• saprophytic fungi and saprophytic bacteria

CLASSIFICATION OF BIOTIC COMPONENTS INTO TROPHIC LEVEL

Food chain

• A series of organisms through which energy is transferred in the form of food

• trophic level - each stages in the food change and can be shown in the form of pyramid number

• pyramid number show the interaction between a producers and consumers and the number of organisms

• during food transfer from one trophic level to next level a lot of energy is lost ( through undigested matter, excretory products, lost as heat during respiration)

• 90% : energy is lost

• 10% : transfer from one trophic level to the next

Food web

• in a community, food chains are linked together to form a food web

• gives a more complete picture of the feeding relationship in a community

INTERACTION BETWEEN ORGANISMS

Symbiosis Saprophytism Prey-predator Competition

Commensalism Mutualism Parasitism

Symbiosis

• Interaction in which there is a close and permanent relationship between two specific organisms

• One species : benefits

• One species : unaffected, harmed or helped

Symbiosis

Commensalism • ( + , 0 )• example - clown fish & sea anemones - pigeon orchid

Mutualism

• ( + , + )

• example

- lichens

- root nodules

Parasitism

• ( + , - )

• example

- flea

- tapeworm

+ : benefits0 : neither benefit nor harm- : harm

Epiphytes(plant)

Epizoics(animal)

Ectoparasite Endoparasite

Saprophytism

A type of interaction in which living organisms obtain food from dead and decaying organic matter

Enzymes are secreted onto the food and digestion occurs outside the cell

Example : saprophyte (plant) : fungus saprozoite (animal) : earthworm

Prey-predator(+ ,- )

• predator

- kills other animal for food

- larger and fewer in number than its prey

- the number of predator affects the

size of prey population

• prey

- the animal that kill by the predator

- must be able to protect itself from being killed

• example : owls & snakes, frogs & snakes

prey

predator

Time

Number

Competition

An interaction between organisms which live together In a habitat and compete for the same resources that are

in limited supply

Intraspecific

Competition between individuals of the same species

Compete for light, water, space and nutrients

Example : Bryophyllum sp

Interspecific

Competition between individualsof different species

Example : paramecium aurelia& paramecium caudatum

Number

the winner

the loser

Time

Interspecific competition

ECOSYSTEM

• An ecological system formed by the interaction of living organisms and their non-living environment

• Example : Mangrove, swamp, desert, marine forest

THE PROCESS OF COLONISATION AND SUCCESSION IN AN ECOSYSTEM

COMMUNITY

• A population of organisms living together within the same habitat

• represent biotic components of an ecosystem

•Example : various group of organisms living in forest

POPULATION

• A group of individuals of the same species occupying the same habitat

• expressed by density

•The rate of change of a population density depends on birth rate, death rate and migration

SPECIES

•A group of closely related organisms which are capable of interbreeding to produce fertile offspring

ECOSYSTEM

COMMUNITY

POPULATION

SPECIES

HABITAT

• The place where the organism lives

• organism obtain its food, shelter and reproduces in its habitat

• example : ponds, rivers, forests

• within an ecosystem there will be several habitats

• microhabitat : smaller division of an a habitat

NICHE

• Is the function of an organism or the role it plays in the habitat

• organisms can live in the same habitat but they occupy different niches

• includes its habitat, its interaction, the types of food it consumes, the range of temperature it tolerate and the spaces it occupies

•Example : a caterpillar and aphid live in the same habitat (caterpillar eats the leaf but aphid sucks sap from the leaf)

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COLONISATION & SUCCESSION IN DISUSED PONDSCOLONISATION & SUCCESSION IN DISUSED PONDS

How does a disused pond become tropical rainforest ?

Mangrove swampPond

LEARNING OUTCOMESLEARNING OUTCOMES Explain the process of colonization,Explain the process of colonization, Explain the process of succession,Explain the process of succession, Identify the successors in an ecosystem,Identify the successors in an ecosystem, Identify the dominant species in an ecosystemIdentify the dominant species in an ecosystem Identify the adaptive characteristic of pioneer species,Identify the adaptive characteristic of pioneer species, Identify the adaptive characteristics of successors,Identify the adaptive characteristics of successors, Explain the changes in habitat caused by pioneer Explain the changes in habitat caused by pioneer

species,species, Explain the changes in habitat caused by successors at Explain the changes in habitat caused by successors at

every level of succession until a climax community is every level of succession until a climax community is reached,reached,

Relate the abiotic components with the biotic Relate the abiotic components with the biotic components in an ecosystem during the processes of components in an ecosystem during the processes of colonization and succession.colonization and succession.

COLONISASIONCOLONISASION Occurs in newly formed areas where no life Occurs in newly formed areas where no life

previously existed previously existed The first colonisers : The first colonisers : pioneer speciespioneer species Special adaptation of pioneer species Special adaptation of pioneer species

1) 1) hardyhardy plant plant 3) have 3) have good dense root systemgood dense root system (bind sand (bind sand particles particles and hold water + humus)and hold water + humus)4) have 4) have shortshort life cycle life cycle5) when die, their remains add to humus 5) when die, their remains add to humus

contentcontent Examples : grasses, ferns & sedges Examples : grasses, ferns & sedges

SUCCESSIONSUCCESSION The process in which The process in which one community changes its one community changes its

environment so that it is replaced by another environment so that it is replaced by another communitycommunity

The The gradual & continuousgradual & continuous process process Leads to a final and stable community which is in Leads to a final and stable community which is in

equilibrium with its environment and is known as equilibrium with its environment and is known as climax climax community community

Successor speciesSuccessor species : a series of plant that replaced the : a series of plant that replaced the pioneer species (herbaceous plant)pioneer species (herbaceous plant)

Successor : Successor : 1) 1) grow biggergrow bigger than pioneer thus reduced the than pioneer thus reduced the

amount of amount of sunlight sunlight 2) 2) have small wind- dispersable seedshave small wind- dispersable seeds (able to spread and grow rapidly)(able to spread and grow rapidly)3) can 3) can change the structurechange the structure and quality of soil for and quality of soil for

larger plant to grow example shrubs larger plant to grow example shrubs

Dominant speciesDominant species : grow faster and dominate the : grow faster and dominate the slower growing pioneer and successor speciesslower growing pioneer and successor species

Dominant species turn modify the environment Dominant species turn modify the environment which allows larger tree to growwhich allows larger tree to grow

The larger trees provide shade and the shrubs The larger trees provide shade and the shrubs cannot compete and are replaced by forest floor cannot compete and are replaced by forest floor speciesspecies

Ecological succession leads to a relatively stable Ecological succession leads to a relatively stable community which is a community which is a climax communityclimax community

EXAMPLE :

From bare ground → forest

COLONISATION & SUCCESSION IN DISUSED PONDSCOLONISATION & SUCCESSION IN DISUSED PONDS

1 Submerged/ sunken plant

Plankton

Begin pioneer species which is submerged plant like Begin pioneer species which is submerged plant like HydrillaHydrilla sp., sp., CabombaCabomba sp., sp., ElodeaElodea sp. sp.

Submerged species are autotrophs (carry out photosynthesis)Submerged species are autotrophs (carry out photosynthesis) When they die, they contributes debris/humus (which supplies When they die, they contributes debris/humus (which supplies

nutrients for next group, successor) nutrients for next group, successor) The decomposition of dead pioneers species & soil erosion will add The decomposition of dead pioneers species & soil erosion will add

silt & reduce water levelsilt & reduce water level The new environment is now suitable for 1The new environment is now suitable for 1stst successor (floating successor (floating

plant)plant)

2

The floating plant like The floating plant like LemnaLemna sp., sp., EichorniaEichornia sp., sp., NympheaNymphea sp. will sp. will replace the pioneer groupreplace the pioneer group

They have broad leaves which cover the water surfaceThey have broad leaves which cover the water surface The pioneer group receive less light for photosynthesis The pioneer group receive less light for photosynthesis Thus, the population of pioneer group decreases Thus, the population of pioneer group decreases The accumulation of humus increases graduallyThe accumulation of humus increases gradually The pond become shallower The pond become shallower This leads to the growth of 2This leads to the growth of 2ndnd successor (emergent/amphibian successor (emergent/amphibian

palnt)palnt)

Floating plant

3

The emergent plant such as cattails & sedges (Thypa sp., Cyperus The emergent plant such as cattails & sedges (Thypa sp., Cyperus sp.) will replace the floating plantssp.) will replace the floating plants

They can live both water and on land They can live both water and on land In earlier stages, these plant grow near the pond sideIn earlier stages, these plant grow near the pond side As the accumulation of humus and silt increases, they will dominate As the accumulation of humus and silt increases, they will dominate

further in until the whole pond becomes landfurther in until the whole pond becomes land

Emergent/ amphibian plant

4

The accumulation of humus makes land more fertileThe accumulation of humus makes land more fertile The creepers, herb plants and shrub will replace the emergent The creepers, herb plants and shrub will replace the emergent

plantsplants The land now covered by bushes The land now covered by bushes

Grasses

5

Over a period of time, the bushes will replaced by a primary Over a period of time, the bushes will replaced by a primary forestforest

Finally, it reaches the climax community Finally, it reaches the climax community Example : Example :

tropical rain forest in Malaysiatropical rain forest in Malaysia

Hydrilla sp. (water weed)

Elodea sp. (water weed)

Cabomba sp. (fan wort)

Submerged/ sunken plant

Lemna sp. (duck weed)

Eichornia sp. (water hyacinth)

Nymphaea sp. (water lily)

Floating plant

Thypa sp. (cattails) Cyperus sp. (sedges) Fimbristylis sp. (sedges)

Emergent / amphibian plant

MANGROVE SWAMPMANGROVE SWAMP

MANGROVE SWAMPMANGROVE SWAMP Found in tropical & subtropical regions Found in tropical & subtropical regions

where freshwater meets salt waterwhere freshwater meets salt water Characteristics :Characteristics :

1) Soft & muddy soil1) Soft & muddy soil

2) High concentration of salt2) High concentration of salt

3) Low level of oxygen3) Low level of oxygen

4) Exposed to high intensities of 4) Exposed to high intensities of sunlight sunlight & strong wind & strong wind

4 species of mangrove : 4 species of mangrove :

1) 1) AvicenniaAvicennia sp. sp.

2) 2) SonneratiaSonneratia sp. sp.

3) 3) RhizophoraRhizophora sp. sp.

4) 4) Brugeria Brugeria sp.sp. The mangrove plants are well adapted to The mangrove plants are well adapted to

the harsh conditions of these regions.the harsh conditions of these regions.

ADAPTATIONS OF MANGROVE PLANTSADAPTATIONS OF MANGROVE PLANTS

PROBLEMSPROBLEMS ADAPTATIONSADAPTATIONS

Soft, muddy soilSoft, muddy soil

Strong coastal windStrong coastal wind

AvicenniaAvicennia sp. : underground sp. : underground cable cable rootsroots (long & branch) (long & branch)

RhizophoraRhizophora sp. : sp. : prop rootsprop roots (aerial roots)- for anchor & (aerial roots)- for anchor & aerationaeration

Waterlogged conditions of Waterlogged conditions of soil (↓ amount of Osoil (↓ amount of O22))

AvicenniaAvicennia sp. : breathing roots sp. : breathing roots ((pneumatophorespneumatophores), grow ), grow vertically upwardsvertically upwards

Gaseous exchange through Gaseous exchange through lenticelslenticels (on the bark) (on the bark)

Direct exposure to the sun Direct exposure to the sun

(↑ rate of transpiration)(↑ rate of transpiration)

Leaves are covered by a thick Leaves are covered by a thick layer of layer of cuticle cuticle

Leaves are Leaves are thick & succulentthick & succulent (able to store water)(able to store water)

High salinity of the sea water High salinity of the sea water

(soil hypertonic compared to (soil hypertonic compared to the cell sap of the root cells)the cell sap of the root cells)

The cell sap in the roots cells The cell sap in the roots cells has a has a higher osmotic higher osmotic pressurepressure (hypertonic) than the (hypertonic) than the soil.soil.

The excess salt is excreted as The excess salt is excreted as crystalline salt from crystalline salt from hydatodeshydatodes (pores on the (pores on the lower epidermis)lower epidermis)

Seeds which fall onto the Seeds which fall onto the ground die (submerged in the ground die (submerged in the soft & waterlogged)soft & waterlogged)

ViviparityViviparity : seeds are able to : seeds are able to germinate while still attached germinate while still attached to the mother plantto the mother plant

Props roots

Excretion of crystalline salt from hydathodes Viviparity

Pneumatophores

Cable roots

Pioneer speciesAdaptations :

• pnematophores• aerenchyma tissue

• viviparous seedlings

Successor speciesAdaptations:• props roots

Successor speciesAdaptations :

• buttress roots• viviparous seedlings

• hydatodes• thick & succulent leaves

• waxy cuticles

COLONISATION & SUCCESSION IN MANGROVE SWAMPSCOLONISATION & SUCCESSION IN MANGROVE SWAMPS

COLONISATIONCOLONISATION The pioneer species : The pioneer species : AvicenniaAvicennia sp. & sp. & SonneratiaSonneratia sp. sp. The extensive roots system of The extensive roots system of AvicenniaAvicennia sp. & sp. & SonneratiaSonneratia sp. sp.

collect sediments & organic mattercollect sediments & organic matter As times passes, the soil become more compact & firmAs times passes, the soil become more compact & firm

SUCCESSIONSUCCESSION RhizophoraRhizophora sp. replaces the pioneer species sp. replaces the pioneer species The arcing roots of The arcing roots of RhizophoraRhizophora sp. trap silt & mud, creating a firmer sp. trap silt & mud, creating a firmer

soil structure.soil structure. As times passes, the ground becomes higher & the soil becomes As times passes, the ground becomes higher & the soil becomes

drierdrier Bruguiera Bruguiera sp. replaces sp. replaces RhizophoraRhizophora sp. sp. The buttress roots of The buttress roots of Bruguiera Bruguiera sp. Form loops which protrude from sp. Form loops which protrude from

the soil to trap more silt and mud. The soil structure changesthe soil to trap more silt and mud. The soil structure changes Over time, terrestrial plants ( Over time, terrestrial plants ( Nypa fruticansNypa fruticans & & PandanusPandanus sp. replace sp. replace

Bruguiera sp.Bruguiera sp. As times passes, the tropical plants replace the terrestrial plants to As times passes, the tropical plants replace the terrestrial plants to

form climax communityform climax community

POPULATION ECOLOGYPOPULATION ECOLOGY Population ecology : a branch of ecology that Population ecology : a branch of ecology that

studies the structure and dynamics of populationsstudies the structure and dynamics of populations Population density : the number of organisms per Population density : the number of organisms per

unit area of the habitatunit area of the habitat Population density is affected by abiotic, biotic, birth Population density is affected by abiotic, biotic, birth

rate, death rate immigration & emigration.rate, death rate immigration & emigration. Sampling technique : estimate the total population Sampling technique : estimate the total population

size of the organismssize of the organisms Type of sampling technique : Type of sampling technique :

1) quadrat sampling technique (plant)1) quadrat sampling technique (plant)2) the capture, mark, release & 2) the capture, mark, release &

recapture recapture technique (animal) technique (animal)

Quadrat sampling technique Quadrat sampling technique (plant)(plant)

• Used to estimating the size of plant populations

• Made from a metal or a wooden frame

• The quadrat is placed randomly in the ecosystem

FORMULA FORMULA

Frequency : the number of times a particular species is found present when a quadrat is thrown a certain number of times

Frequency : Number of quadrats containing the species Number of quadrats

X 100%

Density : the mean number of individuals of a species per unit area

Density : Total number of individuals of a species in all quadrats Number of quadrats X quadrat area

Percentage coverage : an indication of how much area of the quadrat is occupied by a species.

Percentage coverage : Aerial coverage of all quadrats (m2) Number of quadrats X quadrat area

X 100%

Capture, mark, release & Capture, mark, release & recapture technique (animal)recapture technique (animal)

• Used to estimate the populations of mobile animals• The method :

1) A specific animal sample is captured 2) The animal is marked (a ring, a tag or waterproof coloured ink/paint). 3) The marked animals are released into the general population 4) After suitable period of time, a second sample are recaptured 5 ) The number of marked animal is recorded

FORMULAFORMULA

Population size : (no of individuals in the 1st sample) X (no of individuals in the 2nd sample) no of marked individuals recaptured

8.4 BIODIVERSITY8.4 BIODIVERSITY Refers to the diverse species of plants and

animals interacting with one another on Earth Taxonomy : a branch of biology concerned with identifying, describing and

naming organisms Organism are classified into 5 major kingdoms :

1) Monera2) Protista3) Fungi4) Plantae5) Animalia

Monera

N : Monera

C : - prokaryotic organisms (unicellular organisms)

- no distinct nuclear membrane

- The cell wall is present but lack of both membrane-bound nuclei and

organelles

- No tissues formation

- They can be photosynthetic and non-photosynthetic

E : Bacteria and cynobacteria

Protista

N : Protista

C : - have a nuclear and organelles that surrounded by membrane

- may be unicellular or multicellular (algae and protozoa)

- they can either be heterotrophic or autotrophic or even both

- the cell of multicellular, are not specialised to perform specific functions

in the organisms

- some have both plant and animal characteristic

E : Amoeba, Paramecium, Spirogyra and Chlamydomonas

Fungi N : Fungi

C : - heterotrophic multicellular and some are unicellular

- the cell walls of fungi contain chitin

- the main bodies consists of network of thread-like hyphae called mycelium

- do not chlorophyll

- produce spores for reproduction

- become saprophytic and some are parasitisms

E : Mould (Mucor), mushrooms and yeast

Plantae N : Plantae

C : - include all land plants

- have a chlorophyll and carry out photosynthesis

- multicellular

- cells are specialise into tissues

E : mosses, fern, conifers and flowering and non-flowering plant

AnimaliaN : Animalia

C : - multicellular, heterotrophic and eukaryotes

- animal cell do not have cell wall

- mobile

- do not have chlorophyll

E : invertebrate, fish, reptiles,, bird and mammals

Kingdom

Phylum

Class

Family

Order

Genus

Species

A group of organisms sharing certain basic features

A group of organisms has closely related classes

A group of organisms has closely related order

A group of organisms has closely related families

A group of organisms has closely related genera

A group of organisms has closely related species

A group of organisms are very similar, but they still have individual different

The Hierarchy in the Classification of Organisms

Linnaeus Binomial System Classification

1. The modern system of naming animals and plants is based on the Linnaeus Binomial System develop by Carolus Linnaeus

2. The Linnaeus Binomial System of classification uses two words to name every species of organisms found.

i) the first word in the name refers to the genus

ii) the second word is the specific name

3. The characteristics of the system are as follows:

i) both names are in Latin words

ii) the name of the genus is written first and the first letter should be

in upper case. The name of the species is written in lower case

iii) both names are in italics if typed or underlined if written

Common name Scientific name

Paddy Oryza sativa

Durian Durio zibethinus

Oil palm Elaeis guineensis

Rambutan Nephelium lappacium

Sugar cane Saccharum officinarum

Chicken Gallus domesticus

Toad Bufo melanosticus

Frog Rana erythraeu

Scientific names of some local organisms

Kingdom

Phylum

Class

Family

Order

Genus

Species

Animalia Animalia

Chordata Chordata

Mammalia Mammalia

Carnivora Carnivora

Canidae Canidae

Canis Canis

familiaris lupus

The Hierarchy in the Classification of Organisms

Dog Wolf

The Importance of Biodiversity

Importance of Biodiversity

Shelter

Clean drinking water

Economic resources

Clean air

Sources of food

Sources of medicine

8.5 The impact of microorganisms on life8.5 The impact of microorganisms on life

Microorganisms are tiny organisms that can only seen clearly under the microscope

Microorganism are classified into 5 major types :

1) Virus2) Bacteria3) Algae 4) Protozoa5) Fungi

Bacteria

N : Bacteria

C : - unicellular organisms which have basic cell structure that

includes a cell wall, plasma membrane and DNA that is not

enclosed in a membrane

- have a cell walls made of a polymer called peptidoglycan

- certain bacteria form spores under unfavourable conditions

- their shape may be spherical (coccus), rod shape, (bacillus) or

spiral (spirilium)

E : Lactobacillus sp. and Staphylococcus sp.

Algae

N : Algae

C : - photosynthetic eukaryotic plant-like organisms in the

kingdom protista

- have a chlorophyll and chloroplast

- cell walls are made of cellulose

- do not have leaves, stems or roots

E : phytoplankton and Spirogyra sp.

Fungi N : Fungi

C : - heterotrophic multicellular or unicellular

- do not have chlorophyll

- have a cell walls made up of chitin

- fungi feed by secreting enzymes that break the surrounding

organic material down into simple molecules before they are

absorbed

E : Mucor sp. and yeast

Protozoa

N : Protozoa

C : - unicellular organism

- have nucleus, cytoplasm and plasma membrane

- capable carry out living processes such as respiration,

reproduction and excretion

- they have flagella, cilia or pseudopodia to move

E : Euglena sp., Paramecium sp., Amoeba sp.

Viruses

N : Viruses

C : - is not a living cell because it cannot survive or reproduce on its own outside

the host

- is composed of DNA and RNA, surrounded by a protein coat

- can be crystallised

E : T4 bacteriophage and tobacco mosaic virus

The Effect of Abiotic Components on the Activity of Microorganisms

1.Concentration of nutrient:

- all microorganisms except viruses need nutrient and water for

reproduction and growth.

- without nutrient and water, microorganisms will die or form

spores

2. pH

- most bacteria prefer slightly alkaline condition (pH around 7.4)

- moulds, yeast and protozoa (pH between 4.5 and 5.0)

3. Temperature

- most microorganisms are inactive at low temperatures

- optimum temperature for most microorganisms is between 35 ⁰C and 40 ⁰C

- beyond 60 ⁰C the growth of microorganisms is inhibited

- microorganisms and their spores can only be destroyed when they are sterilized at a temperature of about 121 ⁰C

4. Light intensity

- microorganisms prefer place which are dark or have a low light intensity

- a high intensity of sunlight and ultraviolet rays can kill microorganisms

- however, algae and photosynthetic bacteria need light to photosynthesis

The Role of Useful Microorganisms in the Ecosystem

1. Digestion:

- in stomach, intestine or caecum of herbivors – have a bacteria that produce

cellulases enzymes to digest cellulose to simple sugars

- simple sugar absorbed by the herbivore and symbiotic bacteria

- Termite have a Trichonympha sp. (flagellated protozoan) which is help to digest

cellulose from the wood

2. Medicine

- fungi – produce antibiotic (prevent the growth of bacteria)

- Examples: Penicillium notatum – gonorrhoea, syphilis, lung infection

Streptomycine – tunerculosis (TB)

- dead bacteria or viruses – produce vaccine

- Examples: BCG for TB

3. Decomposition:

- bacteria and saprophytic fungus are microorganisms that feed on dead organic matter to get energy for their life processes.

- play an importance role in the natural cycles of the elements such as the carbon cycle and nitrogen cycle

4. Industry

- production of alcohol – using yeast through the fermentation process of sugar,

starch or grains

- production of vinegar – the bacterium, Acetobacter, acts on alcohol to produce

vinegar (ethanoic acid)

- Making bread – using yeast and sodium bicarbonate to produce carbon dioxide

to rises the bread dough

- Production of butter – cream is made sour by the action of bacteria. Bacteria

split protein from the fat of the cream. This will enable

the fat molecules stick together when the mixture is

stirred strongly

4. Industry

- production of fermented milk – tairu and yogurt

- the bacteria, Lactobacillus sp. and

Streptococcus sp. and yeast

- the milk will become sour and has

smell of alcohol

- production of vitamins – Vitamin B2 – yeast

- Vitamin D – yeast and bacterium

- textile industry – bacteria are use to decomposed the soft plant

tissues leaving the plant fibres

5. Nitrogen cycle

List the function of microorganism in the nitrogen List the function of microorganism in the nitrogen cycle abovecycle above

Nitrogen-fixing bacteriaNitrogen-fixing bacteria Process: Nitrogen FixationProcess: Nitrogen Fixation

1.1. RRhizobiumhizobium sp. (in root nodule) sp. (in root nodule)

CClostridiumlostridium sp. sp. AAnabaenanabaena sp. sp. NNostoc ostoc sp. (cyanobacteria)sp. (cyanobacteria) AAzotobactor zotobactor sp. (live sp. (live freely in soil) freely in soil) fix fix atmosphere nitrogenatmosphere nitrogen into into nitratenitrate (absorb by (absorb by plant & animal)plant & animal)

Putrefying bacteria and fungiPutrefying bacteria and fungi

Process: DecompositionProcess: Decomposition

2.2. Help in putrefaction and Help in putrefaction and decompositiondecomposition

of organic matter into of organic matter into

ammoniaammonia NH3 NH3

Nitrifying bacteria Nitrifying bacteria

Process: NitrificationProcess: Nitrification

3.3. Nitrosomonas Nitrosomonas sp.sp.

NitrococcusNitrococcus sp. sp.

Changes Changes ammoniaammonia into into nitrite, NO2nitrite, NO2 - -

4.4. NitrobacterNitrobacter sp. sp.

Changes Changes nitrite nitrite into into nitrate, NO3 nitrate, NO3 --

Denitrifying bacteria Denitrifying bacteria

Process: DenitrificationProcess: Denitrification

5.5. DenitrifyingDenitrifying bacteria, changes nitrate bacteria, changes nitrate

into nitrogeninto nitrogen

Pathogens, Vectors and Symptoms of Some Diseases

DiseaseDisease Pathogens Pathogens VectorVector SymptomsSymptoms Method of Method of infectioninfection

TBTB BacteriaBacteria -- -Feeling tiredFeeling tired-Constant Constant coughingcoughing-Coughing out Coughing out bloodblood

Droplet infection, Droplet infection, dust, food and dust, food and drinks that are drinks that are contaminatedcontaminated

CholeraCholera Bacteria (Bacteria (VibrioVibrio sp.)sp.)

House House flyfly

-VomitingVomiting-Serious diarrheaSerious diarrhea

Water or food that is Water or food that is contaminatedcontaminated

Food Food poisonipoisoni

ngng

Bacteria, fungiBacteria, fungi House House flyfly

-VomitingVomiting-DiarrhoeaDiarrhoea-Abdominal Abdominal painspains-FeverFever

Water or food that is Water or food that is contaminatedcontaminated

ColdCold VirusVirus -- - Fever, Fever, HeadacheHeadache- Muscle painMuscle pain

Through the airThrough the air

RingwoRingwormrm

FungiFungi -- - Red spot on the Red spot on the skinskin- ItchinessItchiness

TouchTouch

Pathogens, Vectors and Symptoms of Some Diseases

DiseaseDisease PathoPathogens gens

VectorVector SymptomsSymptoms Method of Method of infectioninfection

DengueDengue VirusVirus Mosquito, Mosquito, Aedes Aedes aegyptiaegypti

- High feverHigh fever- HeadacheHeadache-RashesRashes- Pain at the jointPain at the joint-Bleeding from the Bleeding from the nose, gums and nose, gums and tooth socketstooth sockets

Mosquito Mosquito bitebite

Mumps Mumps VirusVirus -- - FeverFever- Painful feeling Painful feeling when when

eatingeating-Difficulty opening Difficulty opening the the

mouthmouth-Soft swelling in Soft swelling in front and front and

below the earsbelow the ears

Through the Through the airair

DiseaseDisease PathogenPathogens s

VectorVector SymptomsSymptoms Method of Method of infectioninfection

AIDSAIDS VirusVirus

(HIV 1 and (HIV 1 and HIV 2)HIV 2)

-- - FeverFever-Loss of body weightLoss of body weight-TirednessTiredness-Candidiasis around Candidiasis around the mouth and throatthe mouth and throat-PneumoniaPneumonia-Kaposis’s sarcoma Kaposis’s sarcoma

-Through sexual Through sexual contact with a contact with a person infected person infected with HIVwith HIV- Transfusion of Transfusion of blood from a HIV blood from a HIV victimvictim-Sharing of Sharing of injection needlesinjection needles

MalariaMalaria Protozoa Protozoa ((PlasmodiuPlasmodiu

mm))

MosquitMosquitoo

- FeverFever-HeadacheHeadache- Muscle painMuscle pain-ShiveringShivering

Mosquito biteMosquito bite

SARSSARS VirusVirus -- - High feverHigh fever-Cry coughCry cough-Shortness of breath Shortness of breath or breathing difficultyor breathing difficulty-PneumoniaPneumonia-Headache, muscular Headache, muscular stiffnessstiffness-Loss of appetiteLoss of appetite-Rash, diarrhoeaRash, diarrhoea

-Droplet infection Droplet infection touchtouch- Close contact with Close contact with someone who has someone who has SARSSARS-Body secretionBody secretion

Transmission of Microorganisms

1.Through five ways :

i) the air

ii) touch

iii) food

iv) vectors

v) water

Controlling Pathogens

Methods of controlling pathogens

Antibiotics

Penicillin and streptomycin are

chemicals produced by microorganisms which inhibit the

growth or kill other microorganisms,

especially bacteria

Vaccines

Are modified or weakened forms of

bacteria or viruses. Is a suspension of dead

bacteria or viruses which is inoculated into our body to induce the

production of antibodies. Examples of vaccine are Sabine vaccine and BCG

Antiseptics

Are used on cuts and wounds to kill and

inhibit the growth of microorganisms.

Examples of antiseptics are

acriflavin and iodine solution

Disinfectants

Use to kill microorganisms on the

floor, buildings or furniture and sterilise surgical equipment. Example : phenol, formaldehyde and

carbolic acid