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Hoe word Raunkiær se plantlewevorme vandag beskou?

Hoe word Raunkiær se plantlewevorme vandag beskou?


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Aan die begin van die 20ste eeu het Raunkiær 'n tipologie van plantlewensvorme voorgestel gebaseer op waar hulle hul knoppe dra, ongeveer soos:

kriptofiete: ondergronds

hemikiptofiete: aan die oppervlak

chamaephytes: naby die oppervlak

fanerofiete: bo die oppervlak geprojekteer

Word dit steeds as bruikbare / biologies betekenisvolle kategorieë beskou? Is daar 'n ander tipologie wat verkies word (bv. boom/struik/substruik)? Of beweeg mense na gradiënte van gekwantifiseerde eienskappe in plaas van tipologieë (bv. meet planthoogte, spesifieke blaaroppervlakte, ens.)?


Oreotrefes, dit hang alles af van die behoeftes. Reproduktiewe skemas sluit nie vormskemas uit nie. Daar was egter 'n verskuiwing na kladistiek in klassifikasie, wat beteken om wetenskaplike name SLEGS aan monofiletiese groepe te gee, dit wil sê groepe wat al die afstammelinge van 'n enkele voorouer insluit - en slegs sy afstammelinge. Maar ons gebruik byvoorbeeld steeds boom/struik-onderskeiding en epifiete, maar dit is om die ekologie van spesies te beskryf, om hulle te help identifiseer, nie om hulle op hierdie gronde alleen te klassifiseer nie.


Biosfeer

Die biosfeer bestaan ​​uit die dele van die aarde waar lewe bestaan. Die biosfeer strek van die diepste wortelstelsels van bome tot die donker omgewing van seeslote, tot welige reënwoude en hoë bergtoppe.

Aardwetenskap, Geografie, Fisiese Geografie

Dit lys die logo's van programme of vennote van NG Onderwys wat die inhoud op hierdie bladsy verskaf of bygedra het. Aangedryf deur

Die biosfeer bestaan ​​uit die dele van die aarde waar lewe bestaan. Die biosfeer strek van die diepste wortelstelsels van bome, tot die donker omgewing van seeslote, tot welige reënwoude en hoë bergtoppe.

Wetenskaplikes beskryf die Aarde in terme van sfere. Die soliede oppervlaklaag van die Aarde is die litosfeer. Die atmosfeer is die luglaag wat bokant die litosfeer strek. Die aarde se water op die oppervlak, in die grond en in die lug maak die hidrosfeer uit.

Aangesien lewe op die grond, in die lug en in die water bestaan, oorvleuel die biosfeer al hierdie sfere. Alhoewel die biosfeer ongeveer 20 kilometer (12 myl) van bo na onder meet, bestaan ​​byna alle lewe tussen ongeveer 500 meter (1 640 voet) onder die seeoppervlak tot ongeveer 6 kilometer (3,75 myl) bo seespieël.

Oorsprong van die biosfeer

Die biosfeer bestaan ​​al sowat 3,5 miljard jaar. Die biosfeer se vroegste lewensvorme, genaamd prokariote, het sonder suurstof oorleef. Antieke prokariote het enkelsellige organismes soos bakterieë en archaea ingesluit.

Sommige prokariote het 'n unieke chemiese proses ontwikkel. Hulle kon sonlig gebruik om eenvoudige suikers en suurstof uit water en koolstofdioksied te maak, 'n proses wat fotosintese genoem word. Hierdie fotosintetiese organismes was so volop dat hulle die biosfeer verander het. Oor 'n lang tydperk het die atmosfeer 'n mengsel van suurstof en ander gasse ontwikkel wat nuwe vorme van lewe kon onderhou.

Die byvoeging van suurstof tot die biosfeer het meer komplekse lewensvorme toegelaat om te ontwikkel. Miljoene verskillende plante en ander fotosintetiese spesies het ontwikkel. Diere, wat plante (en ander diere) eet, het ontwikkel. Bakterieë en ander organismes het ontwikkel om dooie diere en plante te ontbind, of af te breek.

Die biosfeer trek voordeel uit hierdie voedselweb. Die oorblyfsels van dooie plante en diere stel voedingstowwe in die grond en see vry. Hierdie voedingstowwe word weer deur groeiende plante geabsorbeer. Hierdie uitruil van voedsel en energie maak die biosfeer 'n selfonderhoudende en selfregulerende stelsel.

Die biosfeer word soms beskou as een groot ekosisteem en mdasha-komplekse gemeenskap van lewende en nie-lewende dinge wat as 'n enkele eenheid funksioneer. Meer dikwels word die biosfeer egter beskryf as met baie ekosisteme.

Biosfeerreservate

Mense speel 'n belangrike rol in die handhawing van die vloei van energie in die biosfeer. Soms ontwrig mense egter die vloei. Byvoorbeeld, in die atmosfeer neem suurstofvlakke af en koolstofdioksiedvlakke verhoog wanneer mense woude skoonmaak of fossielbrandstowwe soos steenkool en olie verbrand. Oliestortings en industriële afval bedreig lewe in die hidrosfeer. Die toekoms van die biosfeer sal afhang van hoe mense met ander lewende dinge binne die sone van lewe omgaan.

In die vroeë 1970's het die Verenigde Nasies 'n projek genaamd Man and the Biosphere Program (MAB) gestig, wat volhoubare ontwikkeling bevorder. 'n Netwerk van biosfeerreservate bestaan ​​om 'n werkende, gebalanseerde verhouding tussen mense en die natuurlike wêreld te vestig.

Tans is daar 563 biosfeerreservate regoor die wêreld. Die eerste biosfeerreservaat is in Yangambi, Demokratiese Republiek van die Kongo, gestig. Yangambi, in die vrugbare Kongo-rivierkom, het 32 ​​000 spesies bome en endemiese spesies soos bosolifante en rooi riviervarke. Die biosfeerreservaat by Yangambi ondersteun aktiwiteite soos volhoubare landbou, jag en mynbou.

Een van die nuutste biosfeerreservate is in Yayu, Ethiopië. Die gebied is vir landbou ontwikkel. Gewasse soos heuning, hout en vrugte word gereeld verbou. Yayu se mees winsgewende en waardevolle hulpbron is egter 'n inheemse plantspesie, Arabiese koffie. Hierdie struik is die bron van koffie. Yayu het die grootste bron van wild Arabiese koffie in die wêreld.

Foto deur Rosanne Atencio Sevilla, MyShot

Biosfeer 2
In 1991 het 'n span van agt wetenskaplikes na 'n groot, selfstandige navorsingsfasiliteit genaamd Biosphere 2 in Oracle, Arizona, ingetrek. Binne 'n enorme kweekhuisagtige struktuur het Biosfeer 2 vyf afsonderlike biome en 'n werkende landboufasiliteit geskep. Wetenskaplikes het beplan om in Biosfeer 2 te woon met min kontak met die buitewêreld. Die eksperimente wat in Biosfeer 2 uitgevoer is, is ontwerp om die verhouding tussen lewende dinge en hul omgewing te bestudeer en om te sien of mense dalk eendag in die ruimte kan lewe.

Die sending was veronderstel om 100 jaar te duur, met twee spanne wetenskaplikes wat elk 50 jaar in die fasiliteit spandeer het. In plaas daarvan het twee spanne dit net vier jaar gemaak, en die wetenskaplikes het in 1994 uitgetrek. Alhoewel die inleeffase verby is, vind navorsing steeds in Biosfeer 2 plaas, met 'n hooffokus op aardverwarming.


Omgewingsbiotegnologie: betekenis, toepassings en ander besonderhede

Omgewingsbiotegnologie is veral die toepassing van prosesse vir die beskerming en herstel van die kwaliteit van die omgewing.

Omgewingsbiotegnologie kan gebruik word om die vrystelling van besoedelingstowwe in die omgewing op 'n aantal maniere op te spoor, te voorkom en te herstel.

Vaste, vloeibare en gasvormige afvalstowwe kan verander word, óf deur herwinning om nuwe produkte te maak, óf deur te suiwer sodat die eindproduk minder skadelik vir die omgewing is. Die vervanging van chemiese materiale en prosesse met biologiese tegnologieë kan omgewingskade verminder.

Sodoende kan omgewingsbiotegnologie 'n beduidende bydrae tot volhoubare ontwikkeling lewer. Omgewingsbiotegnologie is een van vandag’s vinnigste groeiende en mees prakties bruikbare wetenskaplike velde. Navorsing oor die genetika, biochemie en fisiologie van ontginbare mikroörganismes word vinnig vertaal in kommersieel beskikbare tegnologieë om verdere agteruitgang van die aarde’ se omgewing om te keer en te voorkom.

Doelwitte van Omgewingsbiotegnologie (Volgens Agenda 21):

Die doel van omgewingsbiotegnologie is om omgewingsagteruitgang te voorkom, te stop en om te keer deur die toepaslike gebruik van biotegnologie in kombinasie met ander tegnologieë, terwyl veiligheidsprosedures as 'n primêre komponent van die program ondersteun word.

Spesifieke doelwitte is:

1. Om produksieprosesse aan te neem wat natuurlike hulpbronne optimaal benut, deur biomassa te herwin, energie te herwin en afvalgenerering te minimaliseer.

2. Om die gebruik van biotegnologiese tegnieke te bevorder met die klem op bioremediëring van grond en water, afvalbehandeling, grondbewaring, herbebossing, bebossing en grondrehabilitasie.

3. Om biotegnologiese prosesse en hul produkte toe te pas om omgewingsintegriteit te beskerm met die oog op langtermyn ekologiese sekuriteit.

Die gebruik van biotegnologie om besoedelingsprobleme te behandel is nie 'n nuwe idee nie. Gemeenskappe is vir meer as 'n eeu afhanklik van komplekse bevolkings van mikrobes wat natuurlik voorkom vir rioolbehandeling. Elke lewende organisme - diere, plante, bakterieë ensovoorts - neem voedingstowwe in om te lewe en produseer 'n afval as 'n neweproduk. Verskillende organismes benodig verskillende soorte voedingstowwe.

Sekere bakterieë floreer op die chemiese komponente van afvalprodukte. Sommige mikroörganismes voed op materiale wat giftig is vir ander. Navorsingsverwante omgewingsbiotegnologie is noodsaaklik in die ontwikkeling van effektiewe oplossings vir die versagting, voorkoming en omkeer van omgewingskade met behulp van hierdie lewende vorms. Toenemende kommer oor openbare gesondheid en die verswakkende kwaliteit van die omgewing het die ontwikkeling van 'n reeks nuwe, vinnige analitiese toestelle vir die opsporing van gevaarlike verbindings in lug, water en land aangespoor. Rekombinante DNS-tegnologie het die moontlikhede verskaf vir die voorkoming van besoedeling en hou 'n belofte in vir 'n verdere ontwikkeling van bioremediëring.

Toepassings van Omgewingsbiotegnologie:

Omgewingsbeskerming is 'n integrale komponent van volhoubare ontwikkeling. Die omgewing word elke dag deur die aktiwiteite van die mens bedreig. Met die voortdurende toename in die gebruik van chemikalieë, energie en nie-hernubare hulpbronne deur 'n groeiende wêreldbevolking, neem gepaardgaande omgewingsprobleme ook toe. Ten spyte van toenemende pogings om afvalophoping te voorkom en om herwinning te bevorder, blyk die hoeveelheid omgewingskade wat deur oorverbruik veroorsaak word, die hoeveelhede afval wat gegenereer word en die mate van onvolhoubare grondgebruik waarskynlik aan te hou groei.

Die middel kan tot 'n mate bereik word deur die toepassing van omgewingsbiotegnologietegnieke, wat lewende organismes gebruik in die behandeling van gevaarlike afval en besoedelingsbeheer. Omgewingsbiotegnologie sluit 'n wye reeks toepassings in soos bioremediëring, voorkoming, opsporing en monitering, genetiese ingenieurswese vir volhoubare ontwikkeling en beter lewensgehalte.

Bioremediëring verwys na die produktiewe gebruik van mikroörganismes om besoedelingstowwe te verwyder of te ontgift, gewoonlik as kontaminante van grond, water of sedimente wat andersins menslike gesondheid intimideer. Biobehandeling, bio-herwinning en bio-herstel is die ander terminologieë vir bioremediëring. Bioremediëring is nie 'n nuwe praktyk nie. Mikro-organismes word vir baie jare gebruik om organiese materiaal en giftige chemikalieë uit huishoudelike en vervaardigingsafval te verwyder.

Die fokus in omgewingsbiotegnologie vir die bekamping van verskillende besoedeling is egter op bioremediëring. Die oorgrote meerderheid bioremediëringstoepassings gebruik mikroörganismes wat natuurlik voorkom om giftige afval te identifiseer en te filtreer voordat dit in die omgewing ingebring word of om bestaande besoedelingsprobleme op te ruim.

Sommige meer gevorderde stelsels wat geneties gemodifiseerde mikroörganismes gebruik, word getoets in afvalbehandeling en besoedelingsbeheer om moeilik-afbreekbare materiale te verwyder. Bioremediëring kan in situ of in gespesialiseerde reaktore (ex situ) uitgevoer word. Bioremediëring deur mikroörganismes benodig geskikte omgewing vir die skoonmaak van die besoedelde terrein.

Byvoeging van voedingstowwe, terminale elektronontvangers (O2/GEEN2), temperatuur, vog om die groei van 'n spesifieke organisme te bevorder, kan nodig wees vir die mikrobiese aktiwiteit in die besoedelde terrein. Bioremediëringsoperasies kan óf ter plaatse óf buite terrein, in situ of ex situ gedoen word. Bioremediëring het 'n groot potensiaal om water en grond wat deur 'n verskeidenheid gevaarlike besoedelingstowwe, huishoudelike afval, radioaktiewe afval, ens.

Biologiese skoonmaakprosedures maak gebruik van die feit dat die meeste organiese chemikalieë aan ensiematiese aanval van lewende organismes onderwerp word. Die mees algemene benadering is die gebruik van ensieme as plaasvervangende chemiese katalisators. Beduidende vermindering of volledige uitskakeling van harde chemikalieë kan bereik word soos waargeneem word in leer, tekstielverwerking en pulp- en papierbedryf.

Slegs 1-2g hemisellulose word vir 10-15 kg chloor vervang om 1 ton pulp te behandel, waardeur die gechloreerde organiese uitvloeisel aansienlik verminder word. Omgewingsbeskerming en -remediëring kombineer tans biotegnologiese, chemiese, fisiese en ingenieursmetodes.

Die relatiewe belangrikheid van biotegnologie neem toe namate wetenskaplike kennis en metodes verbeter. Die laer vereistes vir energie en chemikalieë, gekombineer met laer produksie van geringe afval, maak dit 'n toenemend wenslike alternatief vir meer tradisionele chemiese en fisiese metodes van remediëring. Toepassings van bioremediëring vir instandhouding van die omgewing is verskeie. In hierdie hoofstuk word 'n paar behandel as hantering van afvalwater en industriële uitvloeisel, grond- en grondbehandeling, lug- en afvalgasbestuur.

Afvalwater en industriële uitvloeisels:

Waterbesoedeling is 'n ernstige probleem in baie lande van die wêreld. Vinnige industrialisasie en verstedeliking het groot hoeveelhede afvalwater gegenereer wat gelei het tot agteruitgang van oppervlakwaterbronne en grondwaterreserwes. Biologiese, organiese en anorganiese besoedelingstowwe besoedel die waterliggame.

In baie gevalle is hierdie bronne onveilig gemaak vir menslike gebruik sowel as vir ander aktiwiteite soos besproeiing en industriële behoeftes. Dit illustreer dat verswakte waterkwaliteit in werklikheid kan bydra tot waterskaarste, aangesien dit die beskikbaarheid daarvan vir beide menslike gebruik en die ekosisteem beperk. Die behandeling van die afvalwater voor wegdoening is wêreldwyd 'n dringende kommer.

In rioolsuiweringsaanlegte word mikroörganismes gebruik om die meer algemene besoedelingstowwe uit afvalwater te verwyder voordat dit in riviere of die see gestort word. Toenemende industriële en landboubesoedeling het gelei tot 'n groter behoefte aan prosesse wat spesifieke besoedelingstowwe soos stikstof- en fosforverbindings, swaar metale en gechloreerde verbindings verwyder.

Metodes sluit in aërobiese, anaërobiese en fisies-chemiese prosesse in vastebedfilters en in bioreaktore waarin die materiale en mikrobes in suspensie gehou word. Riool- en ander afvalwater sal, indien onbehandeld gelaat word, selfsuiwering ondergaan, maar die proses vereis lang blootstellingsperiodes. Om hierdie proses te bespoedig word bioremediëringsmaatreëls gebruik.

Vyf sleutelstadia word egter in afvalwaterbehandeling erken:

a) Voorbehandeling – gruis, swaar metale en drywende puin word verwyder.

b) Primêre behandeling – opgeskorte sake word verwyder.

c) Sekondêre behandeling – bio-oksideer organiese materiale deur aktiwiteite van aërobiese en anaërobiese mikroörganismes.

d) Tersiêre behandeling – spesifieke besoedelingstowwe word verwyder (ammoniak en fosfaat).

e) Slykbehandeling – vaste stowwe word verwyder (finale stadium).

Aërobiese biologiese behandeling:

Druppelfilters, roterende biologiese kontaktors of kontakbeddings bestaan ​​gewoonlik uit 'n inerte materiaal (rotse/as/hout/metaal) waarop die mikroörganismes in die vorm van 'n komplekse biofilm groei. Dit word al meer as 70 jaar vir riool- en afvalwaterbehandeling gebruik. In hierdie prosesse word die afbreekbare organiese materiaal deur die mikroörganismes tot CO geoksideer2 wat na die atmosfeer geventileer kan word.

Geaktiveerde slykproses:

Hierdie proses word gebruik vir die behandeling en verwydering van opgeloste en bioafbreekbare afval, soos organiese chemikalieë, petroleumraffineringsafval tekstielafval en munisipale riool. Die mikro-organismes in geaktiveerde slyk bestaan ​​gewoonlik uit 70-90% organiese en 10-30% anorganiese stowwe.

Die mikroörganismes wat in hierdie slyk voorkom, is gewoonlik bakterieë, swamme, protosoë en rotifers. Petroleumkoolwaterstowwe word afgebreek deur spesies bakterieë (Acinetobacter, Mycobacteria, Pseudomonas ens.), giste, Cladosporium en Scolecobasidium. Plaagdoders (aldrin, dieldrin, parathion, malathion) word ontgift deur die swam Xylaria xylestrix. Pseudomonas ('n oorheersende grondmikr-organisme) kan organiese verbindings soos koolwaterstowwe, fenole, organofosfate, polichlorineerde bifeniele en polisikliese aromaten ontgift.

Benutting van geïmmobiliseerde sianobakterie Phormidium laminosum in batch- en kontinuvloei-bioreaktors vir die verwydering van nitraat, nitriet en fosfaat uit water is deur Garbisu et al. (2003). Blanco et al. (2003) het die biosorpsie van swaarmetaal deur Phormidium laminosum geïmmobiliseer in mikro-poreuse polimeriese matrikse getoon. Foto-bioreaktors word tans gebruik om alge en sianobakterieë onder nougekontroleerde omgewingstoestande te kweek, met die oog op die maak van hoëwaarde produkte (soos beta-karoteen en gamma-linoleïensuur), die ontwerp van doeltreffende afvalwaterbehandelingsprosesse en die verskaffing van nuwe energiebronne .

Die koste van afvalwaterbehandeling kan verminder word deur die omskakeling van afval in nuttige produkte. Swaelmetaboliserende bakterieë kan swaar metale en swaelverbindings uit afvalstrome van die galvaniseringsbedryf verwyder en hergebruik. Die meeste anaërobiese afvalwaterbehandelingstelsels produseer nuttige biogas.

In sommige gevalle is die neweprodukte van die besoedelingbestrydende mikroörganismes self nuttig. Metaan kan byvoorbeeld verkry word uit 'n vorm van bakterieë wat swaweldrank, 'n afvalproduk van papiervervaardiging, afbreek.

Grond- en grondbehandeling:

Soos die menslike bevolking groei, neem die vraag na voedsel van gewasse toe, wat grondbewaring noodsaaklik maak. Ontbossing, oorontwikkeling en besoedeling deur mensgemaakte chemikalieë is net 'n paar van die gevolge van menslike aktiwiteite en sorgeloosheid. Die toenemende hoeveelhede kunsmis en ander landbouchemikalieë wat op grond toegedien is en industriële en huishoudelike afvalverwyderingspraktyke, het gelei tot die toenemende kommer oor grondbesoedeling. Besoedeling in grond word veroorsaak deur aanhoudende giftige verbindings, chemikalieë, soute, radioaktiewe materiale of siekteveroorsakende middels, wat nadelige uitwerking op plantgroei en dieregesondheid het.

Baie spesies swamme kan vir grondbioremediëring gebruik word. Lipomyces sp. kan onkruiddoder parakwat afbreek. Rhodotorula sp. kan bensaldehied na bensielalkohol omskakel. Candida sp. formaldehied in die grond afbreek. Aspergillus niger en Chaetomium cupreum word gebruik om tanniene (wat in looiery-uitvloeistowwe voorkom) in die grond af te breek en sodoende te help met plantgroei.

Phanerochaete chrysosporium is gebruik in bioremediëring van gronde wat met verskillende chemiese verbindings besoedel is, gewoonlik weerbarstig en as omgewingsbesoedelende stowwe beskou. Afname in PCP (Pentakloorfenol) tussen 88-91% binne ses weke is waargeneem in teenwoordigheid van Phanerochaete chrysosporium.

Bioremediëring van gekontamineerde grond is gebruik as 'n veilige, betroubare, koste-effektiewe en omgewingsvriendelike metode vir die afbraak van verskeie besoedelingstowwe. Dit kan op 'n aantal maniere bewerkstellig word, hetsy in situ of deur die grond meganies te verwyder vir behandeling elders.

In situ-behandelings sluit in die byvoeging van voedingsoplossings, die bekendstelling van mikroörganismes en ventilasie. Ex situ behandeling behels die uitgrawing van die grond en die behandeling daarvan bogronds, hetsy as kompos, in grondbanke, of in gespesialiseerde flodderbioreaktors. Bioremediëring van grond is dikwels goedkoper as fisiese metodes en die produkte daarvan is grootliks skadeloos.

Tydens biologiese behandeling verander grondmikro-organismes organiese besoedeling na CO2, water en biomassa. Degradasie kan onder aërobiese sowel as onder anaërobiese toestande plaasvind. Grondbioremediëring kan ook met behulp van bioreaktore bewerkstellig word. Degradasie kan onder aërobiese sowel as onder anaërobiese toestande plaasvind. Grondbioremediëring kan ook met behulp van bioreaktore bewerkstellig word. Vloeistowwe, dampe of vaste stowwe in 'n flodderfase word in 'n reaktor behandel. Mikrobes kan van natuurlike oorsprong wees, gekweek of selfs geneties gemanipuleer.

Navorsing op die gebied van omgewingsbiotegnologie het dit moontlik gemaak om grond wat met minerale olies besmet is, te behandel. Vastefase-tegnologieë word gebruik vir petroleum-besmette gronde wat uitgegrawe word, in 'n inperkingstelsel geplaas word waardeur water en voedingstowwe deursip. Biologiese afbraak van olies het kommersieel lewensvatbaar bewys, beide op groot en klein skaal, in situ en ex situ.

In situ grondbioremediëring behels die stimulering van inheemse mikrobiese populasies (bv. deur byvoeging van voedingstowwe of deurlugting). In hierdie proses word die omgewingstoestande vir die biologiese afbraak van organiese besoedeling so ver moontlik geoptimaliseer. Suurstof moet voorsien word deur kunsmatige beluchting of deur elektronaannemers soos nitrate of suurstofvrystellende verbindings by te voeg. Osoon opgelos in water en H2O2 word soms gebruik wat die organiese kontaminante afbreek.

Met die aanvang van die menslike beskawing is die lug een van die eerste en mees besoedelde komponente van die atmosfeer. Die meeste lugbesoedeling kom van een menslike aktiwiteit: die verbranding van fossielbrandstowwe—aardgas, steenkool en olie—om industriële prosesse en motorvoertuie aan te dryf. Wanneer brandstof onvolledig verbrand word, kom verskeie chemikalieë genaamd vlugtige organiese chemikalieë (VOC's) ook die lug binne. Besoedelingstowwe kom ook van ander bronne af.

Byvoorbeeld, ontbindende vullis in stortingsterreine en stortingsterreine vir vaste afval gee metaangas vry, en baie huishoudelike produkte gee VOC's af. Uitbreidende industriële aktiwiteite het meer kontaminante in die lug bygevoeg.

Die konsep van biologiese lugbehandeling het aanvanklik onmoontlik gelyk. Met die ontwikkeling van biologiese afvalgas-suiweringstegnologie met behulp van bioreaktors—wat biofilters, bio trickling filters, bioscrubbers en membraanbioreaktors insluit—word hierdie probleem versorg. Die werkswyse van al hierdie reaktore is soortgelyk.

Lug wat vlugtige verbindings bevat, word deur die bioreaktors gevoer, waar die vlugtige verbindings van die gasfase na die vloeistoffase oorgedra word. Mikrobiese gemeenskap (mengsel van verskillende bakterieë, swamme en protosoë) groei in hierdie vloeistoffase en verwyder die verbindings wat uit die lug verkry word.

In die biofilters word die lug deur 'n bedding gevoer wat gepak is met organiese materiaal wat die nodige voedingstowwe vir die groei van die mikro-organismes verskaf. Hierdie medium word klam gehou deur die humiditeit van die inkomende lug te handhaaf. Biologiese afgasbehandeling is oor die algemeen gebaseer op die absorpsie van die VOC in die afvalgasse in die waterfase gevolg deur direkte oksidasie deur 'n wye reeks vraatsugtige bakterieë, wat Nocardia sp. en Xanthomonas sp.

Volhoubare ontwikkeling en lewensgehalte hang af van die rasionele, eko-vriendelike gebruik van natuurlike hulpbronne met ekonomiese groei. Om aan hierdie neiging te voldoen, moet nywerheidsontwikkeling verander na volhoubare styl van afbrekende tipe en vir so 'n doel moet skoner tegnologieë aangeneem word.

Volgens die Verenigde Nasies Omgewingsprogram (1996) ‘ definieer die deurlopende toepassing van 'n geïntegreerde voorkomende omgewingstrategie op prosesse, produkte en dienste om eko-doeltreffendheid te verhoog en risiko's vir mense en die omgewing te verminder’ die eko-vriendelike konsep. Die toepassing van voorkomende en skoon konsep kan slegs bereik word deur die 5R-beleide (Olguin et al, 2003).

Vyf omgewingsgonswoorde is die 5R's vir doeltreffende gebruik van energie en beter beheer van afval, wat kan help met volhoubare ontwikkeling en lewensgehalte:

1. Verminder (Vermindering van afval)

2. Hergebruik (Doeltreffende gebruik van water, energie)

3. Herwin (Herwinning van afval)

4. Vervang (Vervanging van giftige/gevaarlike grondstowwe vir meer omgewingsvriendelike insette)

5. Herwin (nuttige nie-giftige fraksies uit afval)

Innovasie en aanvaarding van skoon tegnologie is die teiken van navorsing en ontwikkeling wêreldwyd. Industriële maatskappye ontwikkel prosesse met verminderde omgewingsimpak wat reageer op die internasionale oproep vir die ontwikkeling van 'n volhoubare samelewing. Daar is 'n deurdringende neiging na minder skadelike produkte en prosesse weg van “end-van-pyp” behandeling van afvalstrome. Omgewingsbiotegnologie, met sy toepaslike tegnologieë, is geskik om by te dra tot hierdie tendens.

Ensieme word vir baie jare wyd in nywerhede gebruik. Ensieme, nie-giftig en bioafbreekbaar, is biologiese katalisators wat hoogs bekwaam is en talle voordele bo nie-biologiese katalisators het. Die gebruik van ensiem deur die mens, beide direk en indirek, is al duisende jare lank.

In die afgelope jare het ensieme 'n belangrike rol gespeel in die vervaardiging van dwelms, fyn chemikalieë, aminosure, antibiotika en steroïede. Industriële prosesse kan eko-vriendelik gemaak word deur die gebruik van ensieme. Ensiemtoediening in die tekstiel-, leer-, voedsel-, pulp- en papierbedryf help om ernstige chemikalieë aansienlik te verminder of heeltemal uit te skakel en is ook meer ekonomies in energie- en hulpbronverbruik.

Biotegnologiese metodes kan voedselmateriaal produseer met verbeterde voedingswaarde, funksionele eienskappe, rakstabiliteit. Plantselle wat in fermenteerders gekweek word, kan geure soos vanielje produseer, wat die behoefte om die verbindings uit vanieljebone te onttrek, verminder. Voedselverwerking het baat gevind by biotegnologies vervaardigde chymosien wat gebruik word in kaasvervaardiging alfa-amilase, wat gebruik word in die produksie van hoë-fruktose mieliesiroop en droë bier en laktase, wat by melk gevoeg word om die laktose-inhoud vir persone met laktose-intoleransie te verminder .

Geneties gemanipuleerde ensieme is makliker om te produseer as ensieme wat uit oorspronklike bronne geïsoleer is en word bevoordeel bo chemies gesintetiseerde stowwe omdat hulle nie neweprodukte of ongeure in voedsel skep nie.

Omgewingsopsporing en -monitering:

'n Wye reeks biologiese metodes word gebruik om besoedeling op te spoor en vir die deurlopende monitering van besoedelingstowwe. Die tegnieke van biotegnologie het nuwe metodes om omgewingsprobleme te diagnoseer en normale omgewingstoestande te assesseer sodat mense beter ingelig kan wees oor die omgewing. Toepassings van hierdie metodes is goedkoper, vinniger en ook draagbaar.

Eerder as om grondmonsters te versamel en na 'n laboratorium te stuur vir ontleding, kan wetenskaplikes die vlak van besoedeling op die terrein meet en die resultate dadelik weet. Biologiese opsporingsmetodes met behulp van biosensors en immunotoetse is ontwikkel en is nou in die mark. Mikrobes word gebruik in biosensors besoedeling van metale of besoedelingstowwe. Saccharomyces cerevisiae (gis) word gebruik om sianied in rivierwater op te spoor terwyl Selenastrum capricornatum (groen alg) vir swaarmetaalopsporing gebruik word. Immunoassays gebruik gemerkte teenliggaampies (komplekse proteïene wat in biologiese reaksie op spesifieke middels geproduseer word) en ensieme om besoedelingsvlakke te meet. As 'n besoedelstof teenwoordig is, heg die teenliggaam homself daaraan, wat dit opspoorbaar maak deur kleurverandering, fluoressensie of radioaktiwiteit.

'n Biosensor is 'n analitiese toestel wat 'n biologiese reaksie in 'n fisiese, chemiese of elektriese sein omskakel. Die ontwikkeling van biosensors behels die integrasie van 'n spesifieke en sensitiewe biologies-afgeleide waarnemingselemente (geïmmobiliseerde selle, ensieme of teenliggaampies) word geïntegreer met fisies-chemiese transduktors (óf elektrochemies of opties). Geïmmobiliseer op 'n substraat, verander hul eienskappe in reaksie op een of ander omgewingseffek op 'n manier wat elektronies of opties waarneembaar is.

Dit is dan moontlik om kwantitatiewe metings van besoedelingstowwe te maak met uiterste akkuraatheid of tot baie hoë sensitiwiteite. Die biologiese reaksie van die biosensor word bepaal deur die bio-katalitiese membraan, wat die omskakeling van reaktant na produk bewerkstellig. Geïmmobiliseerde ensieme beskik oor 'n aantal voordelige eienskappe wat hulle veral toepaslik maak vir gebruik in sulke stelsels.

Hulle kan hergebruik word, wat verseker dat dieselfde katalitiese aktiwiteit teenwoordig is vir 'n reeks ontledings. Biosensors is kragtige instrumente wat staatmaak op biochemiese reaksies om spesifieke stowwe op te spoor, wat voordele ingehou het vir 'n wye reeks sektore, insluitend die vervaardiging, ingenieurswese, chemiese, water, voedsel en drank industrieë. Hulle is in staat om selfs klein hoeveelhede van hul spesifieke teiken chemikalieë vinnig, maklik en akkuraat op te spoor.

Vir hierdie karakter van biosensors is hulle ywerig aangeneem vir 'n verskeidenheid prosesmoniteringstoepassings, hoofsaaklik ten opsigte van besoedelingsevaluering en -beheer. Biosensors vir die opsporing van koolhidrate, organiese sure, glukosinolate, aromatiese koolwaterstowwe, plaagdoders, patogeniese bakterieë en ander is reeds ontwikkel.

Die biosensors kan ontwerp word om baie selektief te wees, of sensitief vir 'n wye reeks verbindings. Byvoorbeeld, 'n wye verskeidenheid van onkruiddoders kan opgespoor word in rivierwater met behulp van alg-gebaseerde biosensors die spanning toegedien op die organismes gemeet word as veranderinge in die optiese eienskappe van die plant’s chlorofil. Biosensors is van verskillende tipes soos kalorimetriese biosensors, immunosensors, optiese biosensors, BOD-biosensors, gasbiosensors.

Die merkwaardige vermoë van mikrobes om chemikalieë af te breek, blyk nuttig te wees, nie net in die remediëring van besoedeling nie, maar ook in die opsporing van besoedeling. 'n Groep wetenskaplikes by Los Alamos Nasionale Laboratorium werk met bakterieë wat 'n klas organiese chemikalieë genoem fenole afbreek. Wanneer die bakterieë fenoliese verbindings inneem, heg die fenole aan 'n reseptor.

Die fenol-reseptorkompleks bind dan aan DNS, wat die gene wat betrokke is by die afbreek van fenol aktiveer. Die Los Alamos-wetenskaplikes het 'n verslaggewergeen bygevoeg wat, wanneer dit deur 'n fenol-reseptorkompleks geaktiveer word, 'n maklik waarneembare proteïen produseer, wat dus die teenwoordigheid van fenoliese verbindings in die omgewing aandui. Biosensors wat asetielcholienesterase gebruik kan gebruik word vir die opsporing van organofosforverbindings in water.

Biotegnologie, wat na verwagting 'n groot bydrae tot die welsyn van die mensdom sal lewer, is 'n belangrike tegnologie wat voortdurend ontwikkel behoort te word. Die toepassing van DNS-tegnologie, onder die verskillende soorte biotegnologie, het die moontlikheid om nuwe geenkombinasies te skep wat nie voorheen in die natuur bestaan ​​het nie.

Sedert sy begin het genetiese ingenieurswese beweer dat hulle in staat is om pasgemaakte mikroörganismes met verbeterde afbrekende vermoëns vir giftige stowwe te konstrueer. Met die ontwikkeling van GEM (geneties gemanipuleerde mikroörganisme) en hul moontlike benutting in die behandeling van besmette grond en water, is stabiliteit van plasmiede uiters wenslik. Plasmiede is sirkelvormige DNA-stringe wat as aparte entiteite repliseer onafhanklik van die gasheerchromosoom. Plasmiede kan in grootte wissel van dié wat net 'n paar gene dra tot dié wat baie groter getalle dra. Klein plasmiede kan as veelvuldige kopieë teenwoordig wees. Uitruiling van genetiese inligting via plasmiede word verkry deur die proses van vervoeging.

Die gebruik van beperkingsensieme het die isolasie van spesifieke DNA-fragmente moontlik gemaak wat oorgedra kan word na 'n ander organisme wat nie dieselfde is nie. Genes which code for metabolism of environmental pollutants such as PCB’s and other xenobiotic compounds are frequently, although not always, located on plasmids.

The possibility of genetic transfer in non-biodegradative microbes has opened a new outlook of bio treatment of wastes. The recombinant DNA has the ability to multiply and may also confer the specific derivative capacity to detoxify environmental contaminants.

Gene transfer among microbial communities has improved the derivative capacity in vitro. The first patent for a genetically modified organism (GMO) or GEM, filed in the USA by Professor A. M. Chakrabarty was for a bacterium Pseudomonas putida with hydrocarbon degrading abilities. Subsequent reports have noted the role of plasmids in degradation of alkanes, naphthalene, toluene, m— and p— xylenes.

Given the overwhelming diversity of species, biomolecules and metabolic pathways on this planet, genetic engineering can, in principle, be a very powerful tool in creating environmentally friendlier alternatives for products and processes that presently pollute the environment or exhaust its non-renewable resources.

Nowadays organisms can be supplemented with additional genetic properties for the biodegradation of specific pollutants if naturally occurring organisms are not able to do that job properly or not quickly enough. By combining different metabolic abilities in the same microorganism blockage in environmental cleanup may be circumvented.

In the USA some genetically modified bacteria have been approved for bioremediation purposes but large scale applications have not yet been reported. In Europe only controlled field tests have been authorized. Just as light, heat, and moisture can degrade many materials, biotechnology relies on naturally occurring, living bacteria to perform a similar function but the action is faster.

Some bacteria naturally feed on chemicals and other wastes, including some hazardous materials. They consume those materials, digest them, and excrete harmless substances in their place. Bioremediation uses natural as well as recombinant microorganisms to break down toxic and hazardous substances already present in the environment. Bio treatment can be used to detoxify waste streams at the source before they contaminate the environment – rather than at the point of disposal. This approach involves carefully selecting organisms, known as biocatalysts, which are enzymes that degrade specific compounds and accelerate the degradation process.

However, the application of GMOs/GEMs, in the environment for bioremediation may create problems in the ecosystem. These exclusively designed organisms do not get a chance to experience the various fluctuating environmental conditions which is faced by naturally occurring organisms during the evolutionary processes spaning millions of years.

As a result, the latter are well adapted to the changing environmental conditions such as changes in temperature, substrate or waste concentrations. But when exposed to the contaminated site, GMOs show a higher viability than naturally occurring bacteria, due to their tailored enzymatic equipment.

There are concerns about the negative effect of these GMOs on the complex and delicate microbial ecosystems by competition or the exchange of genetic material in the soils to which they are applied. Even more worrisome is their potential effect outside the treatment area. While recombinant strains may appear harmless in the laboratory, it is virtually impossible to assess their impact in the field.

Biotechnical methods are now used to produce many proteins for pharmaceutical and other specialized purposes. Human insulin, the first genetically engineered product to be produced commercially (1982) is made by nonvirulent strain of Escherichia coli bacteria, by introduction of a copy of the gene for human insulin.

When the gene is “amplified” the bacterial cells produce large quantities of human insulin that are purified and used to treat diabetes in human beings. A number of other genetically engineered products have been approved since then, including human growth hormone, alpha interferon, recombinant erythropoietin and tissue plasminogen activator.

Biotechnology techniques are being applied to plants to produce plant materials with improved composition, functional characteristics. Among the first commercially available whole food products was the slow-ripening tomato, the gene for polygalacturonase, the enzyme responsible for softening, is turned off in this tomato. Plants that are resistant to disease, pests, environmental conditions, or selected herbicides or pesticides are also being developed.

In 1995, the Environmental Protection Agency (EPA) gave clearance for development of transgenic corn seed, cotton seed, and seed potatoes that contain the genetic material to resist certain insects. The advantage of such products is that they allow the use of less toxic and more environmentally friendly herbicides and pesticides.

The first approved application of biotechnology to animal production was the use of recombinant bovine somatotropin (BST) in dairy cows. Bovine somatotropin, a protein hormone found naturally in cows, is necessary for milk production. When the recombinant BST is administered to dairy cows under ideal management conditions, milk production has been shown to increase by 10% to 25%.

Other uses of biotechnology in animal production include development of vaccines to protect animals from disease, production of several calves from one embryo (cloning), artificial insemination, improvement of growth rate and/or feed efficiency, and rapid disease detection.

Natural bio-pesticides are another development of biotechnology that help farmers reduce chemical use. They degrade rapidly, leave no residues, and are toxic only to target insects. Bacillus thuringiensis (B.t.), produces a protein that is naturally toxic to certain insects. Scientists have extracted the B.t. gene that expresses the insecticide and inserted it into common bacteria that can be grown in large quantities by the same fermentation techniques used to produce such everyday products as beer and antibiotics. Spread on cotton and other crops, these harmless bacteria control insects naturally.

Moreover, a wide range of crop plants have been genetically engineered to express the cry genes (found in B. t.) in their tissues, so the insects get killed as they feed on these crops. Pollution control by genetic engineering is likely to work best when pollutants are a known mixture of relatively concentrated organic compounds that are related to each other in structure, where conventional alternative organic nutrients are absent, and when there is no competition from indigenous microorganisms.

The spectacular metabolic versatility of bacteria and fungi is exploited in the area environmental bioremediation as in sewage and waste water treatment, degradation of xenobiotics and metal abatement. Genetic manipulation offers a way of engineering microorganisms to deal with a pollutant, or a family of closely related pollutants, that may be present in the waste stream from an industrial process.

The simplest approach is to extend the degradative capabilities of existing metabolic pathways within an organism either by introducing additional enzymes from other organisms or by modifying the specificity or catalytic mechanisms of enzymes already present.

A treatment plant at the Homestake Mine in Lead, South Dakota, purifies 4 million gallons of cyanide-containing wastewater a day by completely converting cyanide to nitrate. Pseudomonas sp. convert cyanide and thiocyanate to ammonia and bicarbonate and the nitrifying bacteria Nitrosomonas and Nitrobacter cooperate in converting ammonia to nitrate. Recombinant DNA technology has had amazing repercussion in the last few years in environmental protection and also in other fields for better quality of living.

Different Areas of Environmental Biotechnology:

Environmental Biotechnology and Metagenomics:

Environmental Biotechnology is Divided into Different Areas:

(i) Direct studies of the environment,

(ii) Research with a focus on applications to the environment and

(iii) Research that applies information from the environment to other venues.

Here, a brief account of a particular aspect of direct analysis of environment is given.

In addition to DNA inside living organisms, there is much free DNA in the environment that might also be a source of new genes. The field of environmental biotechnology has revolutionized the study of the life-forms which have not been studied earlier and DNA.

This approach is direct analyses of the environment and the natural biochemical processes that are present. A significant study in this aspect is metagenomics. Metagenomics is the study of the genomes of whole communities of microscopic life forms and it deals with a mixture of DNA from multiple organisms, viruses, viroids, plasmids and free DNA.

In other words, metagenomics, the genomic analysis of a population of microorganisms, is the method to gain access to the physiology and genetics of uncultured organisms.

Using metagenomics, researchers investigate, catalogue the current microbial diversity. New proteins, enzymes and biochemical pathways are identified. The knowledge garnered from metagenomics has the potential to affect the ways we use the environment. Metagenomic analyses involves isolating DNA from an environmental sample, cloning the DNA into a suitable vector, transforming the clones into a host bacterium and screening the resultant transformants.

The clones can be screened for phylogenetic markers such as 16S rRNA and rec A or for other conserved genes by hybridization or multiplex PCR or for expression of specific traits such as enzyme activity or antibiotic production or they can be sequenced randomly.

One very important method for metagenomic study is stable isotope probing (SIP). An environmental sample of water or soil is first mixed with a precursor such as methanol, phenol, carbonate or ammonia that has been labeled with a stable isotope such as 15 N, 13 C or 18 O. If the organisms in the sample metabolize the precursor substrate, the stable isotope is incorporated into their genome.

When the DNA from the sample is isolated and separated by centrifugation, the genomes that incorporated the labeled substrate will be heavier and can be separated from the other DNA in the sample. The heavier DNA will migrate further in a cesium chloride gradient during centrifugation. The DNA can be used directly or cloned into vectors to make a metagenomic library. This technique is useful to find new organisms that can degrade contaminants such as phenol.

Microorganisms are crucial participants in cleaning up a large variety of hazardous substances/chemicals by transforming them into forms that are harmless to people and environment. One very important example is given here. Gasoline is leaked into soil in every gas station in United States.

There is every possibility that gasoline will be mixed with ground water which is the prime source of drinking water. However, the dormant members of the soil microbial community are triggered to become active and degrade the harmful chemicals in gasoline.

Since gasoline is composed of hundreds of chemicals it takes a variety of microbes working together to degrade them all. When some bacteria cause a depletion of O2 in ground water near a gasoline spill, other types of bacteria that can use nitrate for energy begin biodegrading the gasoline. Bacteria that use iron, manganese and sulfate follow.

All these microbial communities work together in a pattern to transform leaking gasoline into CO2 en water. Metagenomic analysis may help us identify the particular community member and function needed to achieve the full chemical transformation that will keep our planet livable.


Threats To Biodiversity

1. Climate Change

Climate change refers to the long term and irreversible change that occurs in the Earth’s climate. This increase in the temperature of the atmosphere has major effects on the environment such as the seasons, rising of the sea levels, and glacial retreats.

  • The biodiversity of organisms are affected regarding their population, distribution, level of the ecosystem, and even the individuals’ morphology and function.
  • Because of the increase in temperature, organisms have already adapted by expanding their ranges in latitudes. Because of this behavior, many species population have declined. Aside from this, many diere have exhibited changes in the timings of their physiological functions. These include the birds and insects migrating and mating earlier than usual, which then result in some failure in breeding and production of young.
  • Regarding ecosystems, studies revealed that climate change has brought the expansion of many desert ecosystems and thus have effects on the function and services that the ecosystem can provide.

For humans, the rapidly increasing rate in climate change imposes great threats for human security as the natural resources are becoming more and more limited. At present, global warming and climate change already have irreversible impacts on biodiversity. And these effects, if not mitigated, can lead to more significant threats in the future.

2. Habitat Loss and Degradation

Habitat loss refers to changes in the environment that result to the rendering of a specific habitat to be functionally valuable. The habitat can no longer accommodate and support the life of the organisms present, thereby declining their population.

  • Habitat loss may either be caused by natural events like natural calamities and geological events or anthropogenic activities like deforestation and man-induced climate change.
  • In the process of habitat degradation, the organisms that were once living in a particular area or region are displaced and are forced to relocate thus resulting in biodiversity reduction.

Indeed, man-made efforts are the prime reasons for habitat loss. At present, the practice of clearing out ecosystems for agriculture conversion and industrial expansion continues to displace organisms of their natural habitat. Other activities include logging and mining.

3. Pollution

Be it water, air, or land pollution, all forms of pollution appear to be a threat to all life forms on Earth. However, it plays a major threat to biodiversity when it comes to the nutrient loading of the elements nitrogen and phosphorus.

  • In Europe, atmospheric nitrogen is the only pollutant that has not decreased in concentration since the implementation of legislation. Its mere presence poses huge challenges to the conservation measures intended to natural habitats and species living there.
  • Furthermore, the presence of nitrogen compounds in water systems can cause eutrophication (excessive plant and algal growth).
  • The presence and accumulation of phosphorus in water systems can alter the way food webs function. Excessive phosphorus, like nitrogen can result to the uncontrolled growth of planktonic alge thus increasing organic matter deposition in the seabed.
  • Another form of pollution that can damage and kill living organisms is acid rain. Acid rain, as its name suggests, is rain that is composed of harmful acids (i.e., nitric and sulfuric acid). This rain is usually a result of pollution coming from the excessive burning of fossil fuels.

Some types of pollution, like the depletion of the ozone layer, can be reversible. However, this shall only happen when humans stop or limit the use of various chemicals that contribute to its destruction.

4. Invasive Species

An exotic or unnatural species can be any kind of organism that has been introduced to a foreign habitat. This introduction can cause major threats to the native species as they often become subjected to great competition for resources, disease, and predation. When these species have successfully colonized the area, they are already called “indringend” ones.

  • Next to habitat loss, invasive species are ranked as the second biggest threat to biodiversity.
  • The greatest threat that invasive species can bring is their capability to change an entire habitat. These species are highly adaptable and can easily dominate a certain area. Because many natural species survive only in a particular environment, they tend to be displaced, or worse, perish.
  • Some places have very low possibilities for the invasion of species. Usually, these places include those with harsh environmental conditions like extreme temperatures and high salinity.

Invasive Species Examples

  • Brown Tree Snake When the brown tree snake was introduced to Guam (an island in Pacific ocean), it wiped out 3/4th of the bird population by eating their eggs and young birds from the nests. This is one of the examples of invasive species by predation. Read more about this here.

Most exotic species are brought to a certain place to replace or add something to the vegetation. It is important to note that not all introduced species become invasive. Most of these attempts have become successful.

5. Overexploitation

Overexploitation refers to the act of overharvesting species and natural resources at rates faster than they can actually sustain themselves in the wild. Because of this, species population is put into great risk of reduction.

  • Overharvesting, overfishing, and overhunting are some examples of overexploitation.
  • Additionally, some species of living organisms find it hard to reproduce when their number is too small.
  • So as a population or ecosystem continues to suffer from low species diversity, the probability of getting wiped out completely when a natural disaster or other forces increases.

If the act of overexploitation continues, it can ultimately bring extinction to many species, even if they still exist in the wild.

6. Other Potential Threats

Aside from the five aforementioned threats, there are still a lot of drivers that may either directly or indirectly contribute to the loss of biodiversity. One good example of this are the epidemics and infectious diseases of wildlife such as Ebola virus disease, infectious bursal disease, and flu. This phenomenon does not only affect wildlife but also human health as well.

  • Aside from this, human-induced activities which include economic, technological and scientific, cultural, and demographic factors also have an impact on biodiversity. The desiccation of wetlands and soils owing to the excessive pumping of water tables oftentimes contributes to the death of organisms living in these environments.
  • The overuse of natural parks and watershed as tourist destinations and recreational spots also threatens biodiversity due to the fact that humans cause too much noise and perturbations that disrupt the animals’ normal activities.

Clearly, human activities have the most significant impact on biodiversity loss. At present, our planet continues to face these threats to biodiversity.

In the future, your children or the younger generation might ask you a question along the lines of, “When the crisis on biodiversity became so rampant during the early 2000s, what did you do about it?” What will your answer be?


Alternation of Generations

Alternation of generations describes a life cycle in which an organism has both haploid and diploid multicellular stages (n represents the number of copies of chromosomes). Haplontic refers to a lifecycle in which there is a dominant haploid stage (1n), while diplontic refers to a lifecycle in which the diploid (2n) is the dominant life stage. Humans are diplontic. Most plants exhibit alternation of generations, which is described as haplodiplodontic. The haploid multicellular form, known as a gametophyte, is followed in the development sequence by a multicellular diploid organism: the sporophyte. The gametophyte gives rise to the gametes (reproductive cells) by mitosis. This can be the most obvious phase of the life cycle of the plant, as in the mosses. In fact, the sporophyte stage is barely noticeable in lower plants (the collective term for the plant groups of mosses, liverworts, and lichens). Alternatively, the gametophyte stage can occur in a microscopic structure, such as a pollen grain, in the higher plants (a common collective term for the vascular plants). Towering trees are the diplontic phase in the life cycles of plants such as sequoias and pines.

Figuur (PageIndex<1>): Alternation of generations of plants: Plants exhibit an alternation of generations between a 1n gametophyte and 2n sporophyte.

Protection of the embryo is a major requirement for land plants. The vulnerable embryo must be sheltered from desiccation and other environmental hazards. In both seedless and seed plants, the female gametophyte provides protection and nutrients to the embryo as it develops into the new generation of sporophyte. This distinguishing feature of land plants gave the group its alternate name of embryophytes.


Why Is Biology Important in Everyday Life?

Biology is important to everyday life because it allows humans to better understand their bodies, their resources and potential threats in the environment. Biology is the study of all living things, so it helps people to understand every organism alive, from the smallest bacteria to California redwoods and blue whales. Professional biologists often concentrate on a small subset of living organisms, such as birds, plants or bacteria.

The study of biology has helped humans to understand the similarities between all forms of life. For example, the genetic code that helps to construct all living organisms is very similar in all life forms. The genetic material is stored in the form of DNA for all plants, animals, bacteria and fungi. By studying the DNA of all these different life forms, biologists have determined that all living creatures are related to each other.

Biology has also helped doctors learn how to keep people healthy and fight off disease. Biologists have learned that things called pathogens, which are themselves other living entities, cause diseases. By understanding how these dangerous organisms work, scientists can fight them off. Because of biology, many people have lived long lives as they have been able to avoid diseases.


What is Endosymbiotic Theory?

How did the eukaryotes become so complicated? And where did these battery-like organelles come from?

We think we know part of the answer. Eukaryotic cells may have evolved when multiple cells joined together into one. They began to live in what we call symbiotic relationships. The theory that explains how this could have happened is called endosymbiotic theory. An endosymbiont is one organism that lives inside of another one. All eukaryotic cells, like your own, are creatures that are made up of the parts of other creatures.

Mitochondria, the important energy generators of our cells, evolved from free-living cells. Click for more detail.

The mitochondrion and the chloroplast are both organelles that were once free-living cells. They were prokaryotes that ended up inside of other cells (host cells). They may have joined the other cell by being eaten (a process called phagocytosis), or perhaps they were parasites of that host cell.

Rather than being digested by or killing the host cell, the inner cell survived and together they thrived. It’s kind of like a landlord and a tenant. The host cell provides a comfortable, safe place to live and the organelle pays rent by making energy that the host cell can use. This happened a long time ago, and over time the organelle and the host cell have evolved together. Now one could not exist without the other. Today they function as a single organism, but we can still find evidence of the free-living past of the organelles if we look closely.


Multidisciplinary research hubs

ARC Centre of Excellence in Plant Energy Biology The Australian Research Council Centre of Excellence in Plant Energy Biology (PEB) is a cutting edge research centre focused on better understanding the way in which plants interconvert forms of chemical energy in response to environmental change.

Our vision is to enhance plant energy efficiency by simultaneously optimising energy capture, conversion and use in changing environments to improve the sustainable productivity of plants. Cooperative Research Centre for Honey Bee Products

The Cooperative Research Centre for Honey Bee Products addresses industry problems limiting the value and expansion of the Australian honey bee products industry.

It aims to make Australian honey renowned as unique, pure and priced for its rarity. The Centre undertakes research to ensure better understanding of the Australian honey bee, its product and its pivotal importance within Australian agriculture.

The UWA Oceans Institute provides state-of-the-art facilities for researchers, industry and government to come together to address the challenges facing our oceans, coasts and estuaries.

Fundamental and applied research is conducted across engineering, biophysical sciences and social sciences to support evidence-based decision-making.

Western Australian Biodiversity Science Institute

The Western Australian Biodiversity Science Institute (WABSI) is a joint venture partnership with leading research organisations, with multi-disciplinary research expertise.

It brings industry, government, researchers and community together to help address WA&rsquos strategic biodiversity priorities through collaborative research.

Western Australian Marine Science Institute

The Western Australian Marine Science Institution (WAMSI) is a leading Australian marine research organisation.

Its structure is like no other because it is a collaboration of State, Federal, industry and academic entities cooperating to create benchmark research and independent, quality scientific information.

It carries out research into climate change, biodiversity, the iconic Ningaloo Marine Park, sustainable fisheries, biotechnology and oceanography, and has overseen the development of a marine bioresources library that will store thousands of marine samples collected by researchers.


Evolution of Eukaryotes

Our own eukaryotic cells protect DNA in chromosomes with a nuclear membrane, make ATP with mitochondria, move with flagella (in the case of sperm cells), and feed on cells which make our food with chloroplasts. All multicellular organisms and the unicellular Protists share this cellular intricacy. Bacterial (prokaryotic) cells are orders of magnitude smaller and have none of this complexity. What quantum leap in evolution created this vast chasm of difference?

Die eerste eukaryotic cells - cells with a kern an internal membrane-bound organelles - probably evolved about 2 billion years ago. This is explained by the endosimbiotiese teorie. As shown in the Figuur below, endosimbiose came about when large cells engulfed small cells. The small cells were not digested by the large cells. Instead, they lived within the large cells and evolved into organelles.

From Independent Cell to Organelle. The endosymbiotic theory explains how eukaryotic cells evolved.

The large and small cells formed a symbiotic relationship in which both cells benefited. Some of the small cells were able to break down the large cell&rsquos wastes for energy. They supplied energy not only to themselves but also to the large cell. They became the mitochondria of eukaryotic cells. Other small cells were able to use sunlight to make food. They shared the food with the large cell. They became the chloroplasts of eukaryotic cells.

Mitochondria and Chloroplasts

What is the evidence for this evolutionary pathway? Biochemistry and electron microscopy provide convincing support. The mitochondria and chloroplasts within our eukaryotic cells share the following features with prokaryotic cells:

  • Their organelle DNA is short and circular, and the DNA sequences do not match DNA sequences found in the nucleus.
  • Molecules that make up organelle membranes resemble those in prokaryotic membranes &ndash and differ from those in eukaryotic membranes.
  • Ribosomes in these organelles are similar to those of bacterial ribosomes, and different from eukaryotic ribosomes.
  • Reproduction is by binary fission, not by mitosis.
  • Biochemical pathways and structures show closer relationships to prokaryotes.
  • Two or more membranes surround these organelles.

The "host" cell membrane and biochemistry are more similar to those of Archaebacteria, so scientists believe eukaryotes descended more directly from that major group (Figuur hieronder). The timing of this dramatic evolutionary event (more likely a series of events) is not clear. The oldest fossil clearly related to modern eukaryotes is a red alga dating back to 1.2 billion years ago. However, many scientists place the appearance of eukaryotic cells at about 2 billion years. Some time within Proterozoic Eon, then, all three major groups of life &ndash Bacteria, Archaea, and Eukaryotes &ndash became well established.

What Does it all Mean?

Eukaryotic cells, made possible by endosymbiosis, were powerful and efficient. That power and efficiency gave them the potential to evolve new characteristics: multicellularity, cell specialization, and large size. They were the key to the spectacular diversity of animals, plants, and fungi that populate our world today. Nevertheless, as we close the history of early life, reflect once more on the remarkable but often unsung patterns and processes of early evolution. Often, as humans, we focus our attention on plants and animals, and ignore bacteria. Our human senses cannot directly perceive the unimaginable variety of single cells, the architecture of organic molecules, or the intricacy of biochemical pathways. Let your study of early evolution give you a new perspective &ndash a window into the beauty and diversity of unseen worlds, now and throughout Earth&rsquos history. In addition to the mitochondria that call your 100 trillion cells home, your body contains more bacterial cells than human cells. You, mitochondria, and your resident bacteria share common ancestry &ndash a continuous history of the gift of life.

The three major domains of life had evolved by 1.5 billion years ago. Biochemical similarities show that eukaryotes share more recent common ancestors with the Archaea, but our organelles probably descended from bacteria by endosymbiosis.


Dr. Monty White Articles

Surely, evolution is about the origin and development of life-forms on earth — what has this got to do with religion? Evolution is science, isn’t it?

Evolution is taken as fact by both unbelievers and some Christians. Monty White demonstrates that evolution has never been proven.

There are hundreds of stories and legends about a worldwide flood. Why do diverse cultures share a strikingly similar story?

The gap theory is simply compromise. It is an attempt to harmonise the facts of Scripture with the ideas of fallen men.

Creationists are often asked, “How is it possible for the earth’s population to reach 6.5 billion people if the world is only about 6,000 years old and if there were just two humans in the beginning?”

It is said that a British newspaper headline once announced “Fog Over Channel—Continent Isolated.” The headline aptly and amusingly sums up Britain’s ambivalent relationship with its neighbors.

In the UK there is a strange paradox—while people are enormously apathetic toward the Christian faith, at the same time they enthusiastically deride it.

Prior to joining AiG, the authors’ letters to newspapers and TV stations would be ignored whenever we would respond to various articles or programmes that dealt with the origins issue.

According to Lord Bertram Russell if human beings do not kill each other through wars, they will probably die of starvation or disease.

It’s not often that a creation conference attracts people from 21 countries. But that’s what happened recently with the largest major in-depth creation conference ever held in the UK.

In the last few years, another compromise of biblical truth has emerged, actually from within what might be termed the ‘Young Earth Creation’ movement. This compromise is the 'Recolonisation Theory.'

In spite of repeated attack on evangelical Christianity in the UK, apparently only 48% of the British public actually believe evolution.

Catholic bishops of England, Wales and Scotland recently published their study book, "The Gift of Scripture." Does the book presume authority to be based on the Bible, or something else?

Stories like these are the latest in a series of insults to the Christian faith in the UK.

Steve Chalke may not be so well known outside the UK, but he is a well-known British evangelical personality who appears regularly on the TV.

A friend of Answers in Genesis wants to use the hype about The Matrix films to direct attention to the reality behind the all-prevailing myth of our day.

Since joining Answers in Genesis, I’ve been giving my own version of this message, titled, “The Origin of the so-called Races,” across the UK.

“Britain’s Greatest Hoax” is the title of the Timewatch investigation of the Piltdown Man fraud, shown on BBC2 television recently.

A country of contrasts is how Bulgaria could be described. It is a very beautiful country but has dilapidated buildings everywhere.

Dr Monty White, head of AiG–UK, was asked to record a three-minute talk for BBC World Update (Radio) on ‘why am I a creationist.’

When Vet author James Herriot wrote about life in Yorkshire last centrury, he probably had no idea that this area of England held a fascinating key to unlocking one of the myths of evolution's long-ag

Recently, there have been reports of two fossils that are not all they appear to be!

Newspapers across the United States carried headlines similar to that of The Cincinnati Post: “Key Ingredients for Life Found in Universe,” with the byline “Chemistry Happens Around Distant Stars.”

During this time I began to realize that the idea of evolution was at best a hypothesis and that it had not been proven. There is not a shred of evidence for the evolution of life on earth.


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