BIOL 131 Assignment 5

PrinciplesofBiology2
Fall2022

Assignment5:Microbes

UploadyouranswerstoBlackboardby11:59pm,FridayOctober7,2022.Youwillgettogether
withyourgroupTuesday(10/11)inclassandpresentyourfindingstotheclass.

Microbes—bacteriaandarchaeaspecifically—haveextremeimportanceinourworld. Theyare
abundant,andfoundineveryhabitat.Theycanbefriends(likehealthygutbacteria)orfoes(like
plantpathogens).

AnswerthequestionsbelowaboutBacteriaandArchaea:

1.Give5keyfactsaboutDomainBacteriathatyoushouldknowfortheexam. (Thesecanbein
bulletpoints)
● maincharacteristicsofaprokaryote
○ smallerthaneukaryoticcells,
○ havenonucleus,andlackorganelles
○ TheyhavesinglecircularDNAasgeneticmaterialandplasmids(forextragenes)
○ Theypossessmesosomesforrespiration.
○ Theyarearchaea
○ Theyareolder
○ Theyadaptandgrowquickly
○ Theyreproduceasexually,throughbinaryfusion/nodiversity

● theevolutionaryhistoryofprokaryotes
○ Oldestfossils;alonefor2billionyears
○ 5000namedspecies,millionsmorepossible
○ Sheerabundance
○ Habitatdiversity,foundeverywhere
○ Extremophileprokaryotes
■ Archaeathatthriveinsaltponds,methanepools,ice

● DistinguishbetweenDomainBacteriaandDomainArchaea
○ Similartobacteria,archaeadonothaveinteriormembranesbutbothhaveacell
wallanduseflagellatoswim.Bacteriacontainpeptidoglycaninthecellwall;
archaeadonot.Thecellmembraneinbacteriaisalipidbilayer;inarchaea,itcan
bealipidbilayeroramonolayer.Bacteriacontainfattyacidsonthecell
membrane,whereasarchaeacontainphytanyl.
● DefinethemaincharacteristicsofthekeylineagesofDomainBacteriaandDomain
Archaea
○ Bacteriaareprokaryoticcells.
○ LiketheEukarya,theyhavemembranescomposedofunbranchedfattyacid
chainsattachedtoglycerolbyesterlinkages