Q:l TF:l Pathogenicl strainsl ofl bacterial tendl tol growl slowerl thanl normall

Q:l T/F:l Pathogenicl strainsl ofl bacterial tendl tol growl slowerl thanl normall non-pathogenicl bacteriall strains

Answer:

False

Pathogenicl strainsl ofl bacterial tendl tol growl fasterl thanl non-pathogenicl strainsl atl 37l degreesl celsiusl whichl isl whyl researchersl mayl setl incubatorsl atl 25l degreesl celsiusl tol restrictl growth

Q:l Whenl givenl anl unknownl bacteriall samplel thel firstl stepl isl tol expandl thel currentl bacteriall population.l Whichl forml ofl medial bestl suitesl thisl need?l Why?A.l MSAl agar B.l LBl medial containingl ampicillinl andl neomycin C.l MacConkeyl agar D.l Bloodl agar

Answer:

D.l Bloodl agar.l Alll thel otherl optionsl arel formsl ofl selectivel medial andl willl inhibitl thel growthl ofl thel unknownl sample.l Althoughl Bloodl agarl isl al differentiall media,l itsl mostl importantlyl non-selective

BIOLl271l /l BIOL271l Modulel 4:l (Latestl

2026/l 2027l Update)l 100%l Verifiedl Questionsl &l Answersl |l Gradel A 1 / 3

Q:l Truel orl False:l Differentiall medial isl bestl suitedl forl distinguishingl betweenl twol similar speciesl ofl bacteria.

Answer:

True

Growthl medial doesl notl containl restricivel factors,l whilel selectivel medial isl bestl used tol encouragel thel growthl ofl onel microbel whilel simultaneouslyl discouragingl the growthl ofl thel other.l Sincel twol similarl speciesl ofl microbesl arel beingl studiedl they mustl bel differentiatedl underl similarl butl justl slightlyl differentl conditionsl (differential media).

Q:l Al researcherl isl askedl tol determinel ifl al samplel containsl Neisserial meningitides.l Knowingl Neisserial meningitidesl isl slowl growingl andl otherl foreignl microbesl mayl alsol bel presentl inl thel culture,l whichl typel ofl medial wouldl bel bestl suited?

Answer:

Selectival Media

Selectivel media.l Ifl additionall foreignl microbesl mayl bel presentl inl yourl samplel and youl knowl Neisserial meningitidesl isl slowl growing,l youl mustl restrictl thel unwanted microbesl whilel supportingl thel growthl ofl Neisserial meningitides.l Thus,l youl are 2 / 3

selectivelyl encouragingl onel microbesl growth,l whilel selectivelyl restrictingl others.

Q:l T/F:l LBl agarl isl classifiedl asl al selective,l non-differentiall media

Answer:

False

LBl agarl isl thel mostl basicl typel ofl agarl andl likel LB,l supportsl thel growthl ofl virtuallyl alll microbesl withoutl restriction

Q:l Anl unknownl microbel isl streakedl ontol al MacConkeyl agarl plate.l Afterl anl overnightl incubationl atl 37°C,l growthl isl observed.l Wouldl al Graml stainl bel necessary?l Whyl orl whyl not?

Answer:

No,l al graml stainl wouldl notl bel necessary,l bcl onlyl gram-negativel microbesl willl growl onl al MacConkeyl agar

Q:l Whichl typel ofl agarl medial isl bestl suitedl tol supportl thel growthl ofl Staphylococcus?

Answer:

Mannitoll saltl agar

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