j j j j j j
Chapterj1:jCellularjBiology
MULTIPLEjCHOICE
1. Whichjstatementjbestjdescribesjthejcellularjfunctionjofjmetabolicjabsorption?
a. Cellsjcanjproducejproteins. c. Cellsjcanjtakejinjandjusejnutrients.
b. Cellsjcanjsecretejdigestivejenzymes. d.j Cellsjcanjsynthesizejfats.
ANS:j C
Injmetabolicjabsorption,jalljcellsjtakejinjandjusejnutrientsjandjotherjsubstancesjfromjtheirjsur
roundings.jThejremainingjoptionsjarejnotjinclusivejinjtheirjdescriptionsjofjcellularjmetaboli
cjabsorption.
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2. Mostjofjajcell’sjgeneticjinformation,jincludingjRNAjandjDNA,jisjcontainedjinjthe:
a. Mitochondria c. Nucleolus
b. Ribosome d.j j Lysosome
ANS:j C
Thejnucleusjcontainsjthejnucleolus,jajsmalljdensejstructurejcomposedjlargelyjofjRNA,jmos
tjofjthejcellularjDNA,jandjthejDNA-
bindingjproteins,jsuchjasjthejhistones,jwhichjregulatejitsjactivity.jThejotherjoptionsjdojnotjco
ntainjmostjofjajcell’sjgeneticjinformation.
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3. WhichjcomponentjofjthejcelljprodNuUceRsSIhNyGd TroBg. CenO M
p eroxide j(H2O2)jbyjusingjoxygenjtojre
movejhydrogenjatomsjfromjspecificjsubstratesjinjanjoxidativejreaction?
a. Lysosomes c. Ribosomes
b. Peroxisomes d.j Oxyhydrosomes
ANS:j B
Peroxisomesjarejsojnamedjbecausejtheyjusuallyjcontainjenzymesjthatjusejoxygenjtojremovejhy
drogenjatomsjfromjspecificjsubstratesjinjanjoxidativejreactionjthatjproducesjH2O2,jwhichjisjajp
owerfuljoxidantjandjpotentiallyjdestructivejifjitjaccumulatesjorjescapesjfromjperoxisomes.jRi
bosomesjarejRNA-
proteinjcomplexesj(nucleoproteins)jthatjarejsynthesizedjinjthejnucleolusjandjsecretedjintojthej
cytoplasmjthroughjporesjinjthejnuclearjenvelopejcalledjnuclearjporejcomplexes.jLysosomesja
rejsaclikejstructuresjthatjoriginatejfromjthejGolgijcomplexjandjcontainjmorejthanj40jdigestivej
enzymesjcalledjhydrolases,jwhichjcatalyzejbondsjinjproteins,jlipids,jnucleicjacids,jandjcarboh
ydrates.jOxyhydrosomesarejinvolvedjinjenzymejproduction.
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4. Whichjcelljcomponentjisjcapablejofjcellularjautodigestionjwhenjitjisjreleasedjduringjcelljinj
ury?
a. Ribosome c. Smoothjendoplasmicjreticulum
b. Golgijcomplex d.j Lysosomes
ANS:j D
, Thejlysosomaljmembranejactsjasjajprotectivejshieldjbetweenjthejpowerfuljdigestivejenzym
esjwithinjthejlysosomejandjthejcytoplasm,jpreventingjtheirjleakagejintojthejcytoplasmicjmat
rix.jDisruptionjofjthejmembranejbyjvariousjtreatmentsjorjcellularjinjuryjleadsjtojajreleasejofj
thejlysosomaljenzymes,jwhichjcanjthenjreactjwithjtheirjspecificjsubstrates,jcausingjcellularj
self-digestion.jThejotherjoptionsjdojnotjcorrectlyjdescribejthisjprocess.
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5. Whatjisjthejsequencejofjstepsjinjthejdevelopmentjofjajdigestivejenzymejbyjthejpancreasjcel
lsjfromjthejinitialjtranscriptionjtojthejreleasejfromjthejcell?
a. ThejenzymejisjtranscribedjfromjDNAjbyjRNAjinjthejnucleus,jproceedsjtojthejrib
osomejforjsynthesis,jandjisjtransportedjinjajsecretoryjvesiclejtojthejcelljmembra
ne.
b. ThejenzymejisjtranscribedjfromjRNAjbyjDNAjinjthejnucleus,jproceedsjtojthejlysoso
mejforjsynthesis,jandjisjtransportedjinjanjencapsulatedjmembranejtojthejcelljmembra
ne.
c. Thejenzymejisjtranscribedjbyjthejmitochondriajinjthejnucleus,jproceedsjtojthejribos
omejforjsynthesis,jandjisjtransportedjinjajcytoskeletonjtojthejcelljmembrane.
d. ThejenzymejisjtranscribedjfromjDNAjbyjRNAjinjthejnucleus,jproceedsjtojthejGolgi
jcomplexjforjsynthesis,jandjisjtransportedjinjajcytosoljtojthejcelljmembrane.
ANS:j A
ThejenzymejisjtranscribedjfromjDNAjbyjRNAjinjthejnucleus,jproceedsjtojthejribosomejforjs
ynthesis,jandjisjtransportedjinjajsecretoryjvesiclejtojthejcelljmembrane.jThejotherjoptionsjdo
jnotjcorrectlyjdescribejthisjprocess.
NURSINGTB.COM
PTS:j j 1 REF:jPagej7j|jFigurej1-5
6. DuringjwhichjphasejofjthejcelljcyclejisjDNAjsynthesized?
a. G1 c. G2
b. S d.j M
ANS:j B
Thejfourjdesignatedjphasesjofjthejcelljcyclejare:j(1)jthejG1j phasej(Gj=jgap),jwhichjisjthejperio
djbetweenjthejMjphasej(Mj=jmitosis)jandjthejstartjofjDNAjsynthesis;j(2)jthejSjphasej(Sj=jsynth
esis),jduringjwhichjDNAjisjsynthesizedjinjthejcelljnucleus;j(3)jthejG2j phase,jduringjwhichjR
NAjandjproteinjsynthesisjoccurs,jthejperiodjbetweenjthejcompletionjofjDNAjsynthesisjandjth
ejnextjphasej(M);jandj(4)jthejMjphase,jwhichjincludesjnuclearjandjcytoplasmicjdivision.
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7. Whatjorganicjcompoundjfacilitatesjtransportationjacrossjcelljmembranesjbyjactingjasjre
ceptors,jtransportjchannelsjforjelectrolytes,jandjenzymesjtojdrivejactivejpumps?
a. Lipids c. Proteins
b. Proteases d.j Carbohydrates
ANS:j C
, Proteinsjactjasj(1)jrecognitionjandjbindingjunitsj(receptors)jforjsubstancesjmovingjinjandjout
jofjthejcell;j(2)jporesjorjtransportjchannelsjforjvariousjelectricallyjchargedjparticlesjcalledjio
nsjorjelectrolytesjandjspecificjcarriersjforjaminojacidsjandjmonosaccharides;jand
(3)jspecificjenzymesjthatjdrivejactivejpumpsjthatjpromotejthejconcentrationjofjcertainjions,j
particularlyjpotassiumj(K+),jwithinjthejcelljwhilejkeepingjconcentrationsjofjotherjions,jforje
xample,jsodiumj(Na+),jbelowjthejconcentrationsjfoundjinjthejextracellularjenvironment.jTh
ejotherjoptionsjdojnotjcorrectlyjdescribejthisjprocess.
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8. Understandingjthejvariousjstepsjofjproteolyticjcascades,jsuchjasjcaspase-
mediatedjapoptosisjandjcomplementjcascades,jmayjbejusefuljinjdesigningjdrugjtherapyjfor
jwhichjhumanjdiseases?
a. Cardiacjandjvascularjdisorders
b. Autoimmunejandjmalignantjdisorders
c. Gastrointestinaljandjrenaljdisorders
d. Endocrinejandjgastrointestinaljdisorders
ANS:j B
Understandingjthejvariousjstepsjinvolvedjinjthisjprocessjisjcrucialjforjdesigningjdrugjinterv
entions.jDysregulationjofjproteasesjfeaturesjprominentlyjinjmanyjhumanjdiseases,jincluding
jcancer,jautoimmunity,jandjneurodegenerativejdisorders.jThejotherjoptionsjdojnotjcorrectlyj
describejthisjprocess.
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9. Whichjstructurejpreventsjwater-
solublejmoleculesjfromjenteringjcellsjacrossjthejplasmaj NURSINGTB.COM
membrane?
a. Carbohydratejchains c. Membranejchanneljproteins
b. Glycoproteinjchannels d.j Lipidjbilayer
ANS:j D
Thejbilayer’sjstructurejaccountsjforjonejofjthejessentialjfunctionsjofjthejplasmajmembrane.jI
tjisjimpermeablejtojmostjwater-
solublejmoleculesj(moleculesjthatjdissolvejinjwater)jbecausejthejwater-
solublejmoleculesjarejinsolublejinjthejoilyjcorejregion.jThejbilayerjservesjasjajbarrierjtojthej
diffusionjofjwaterjandjhydrophilicjsubstancesjwhilejallowingjlipid-
solublejmolecules,jsuchjasjoxygenj(O2)jandjcarbonjdioxidej(CO2),jtojdiffusejthroughjitjreadi
ly.jThejotherjoptionsjdojnotjcorrectlyjdescribejthisjprocess.
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10. Thejfluidjmosaicjmodeljexplains:
a. Howjajcelljmembranejfunctions
b. Whyjourjbodiesjappearjtojbejsolid
c. Howjtissuejisjdifferentiated
d. Howjfluidjmovesjbetweenjthejintracellularjandjextracellularjcompartments
ANS:j A
Thejfluidjmosaicjmodeljaccountsjforjthejflexibilityjofjcellularjmembranes,jtheir
self-
sealingjproperties,jandjtheirjimpermeabilityjtojmanyjsubstances.jThejremainingjoptionsjdojn
otjexplainjthejmosaicjmodel.