science 30 unit a ch 1 suggested answers...like a chambered furnace for the body. there were lots of...

Unit A Maintaining Health

Chapter 1: Circulation and Immunity

Practice, page 9

1. Heart tHeorIes

Person theory about the Heart Limitations of the theory

Galen

The heart is divided in two halves, blood is produced in the liver, and blood moves like ocean tides.

Evidence was gathered only from animal dissections, and there was no experimental testing to support the theory.

Leonardo da Vinci

He drew anatomically correct sketches of the heart. The heart is like a chambered furnace for the body.

There were lots of observations on dead bodies, but human cadaver dissections were not officially permitted, so he did not share his findings.

William Harvey

He had a modern view of the heart. Blood is re-pumped in a closed system of vessels.

Without the technology of the microscope, Harvey could not see capillaries to prove that blood moved from arteries to veins.

2. Solution: strokevolume mL/beat(forfemales)

mL /beat 1L100

=

= ¥

60

6000 mL

L/beat

heartrate beats/minute

cardiacoutput

==

0 060

68

.

== ?

cardiacoutput strokevolume heartrate

Lbeat

= ( ) ¥ ( )

=ÊËÁ

0 060. ˆ̂¯̃

¥( )

==

68

4 08

4 1

beats

min

L/min

L/min

.

.

Thecardiacoutputis4.1L/min.

3. Solution: cardiacoutput L/min

volumepumpedinoneyear

volume

==

4 08.

?

pumpedinoneyear Lmin

minh

hd

da

= ¥ ¥ ¥ =4 08 60 24 365 252 1. .. ¥¥106 L/a

Thevolumepumpedinoneyearis2.1¥106L/a.

4. Sincetheaveragecardiacoutputisjustunder5L/minandtheaveragehumanhas5Lofblood,thismeansthatittakesaboutoneminutetocirculateallthebloodinthebody.

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5. strokevolume mL/beat formales

mL /beat L mL

h

= ( )= ¥

70

70 11000

eeartrate beats/minute

cardiacoutput

==

180

?


L

beat

= ( ) ¥ ( )

=( )

¥0 070. 1180

12 6

13

beatsmin

L/min

L/min

==

.

Thecardiacoutputis13L/min.

6. a. Valuesforcardiacoutputwillvaryforeachstudent.Thefollowingsamplecalculationshowstheresultsforafemalestudentwitharestingheartrateof71beatsperminute.

Solution: strokevolume mL/beat forfemales

mL /beat 1L1000

= ( )= ¥

60

60mmL

L/beat

heartrate beats/minute

cardiacoutput

===

0 060

71

.

?


L

beats

= ( ) ¥ ( )

=( )0 060.

¥¥( )

==

71

4 26

4 3

beats

min

L/min

L/min

.

.

Thecardiacoutputis4.3L/min.

b. Answerswillvary.Thefollowingsamplecalculationfollowsfromquestion6.a.andshowstheresultsforafemalestudentwitharestingheartrateof71beatsperminute.

rate cardiacoutput

L/min

timetofillabarrel

===

4 26.

?

timetofillabarrelvolumeofbarrel

rateL

L

=( )

=( )213

4 26. // min= 50min

Itwouldtakeapump50mintofillthebarrelifitwasoperatingatthesamerateasthecardiacoutput.

c. Iftheheartratedoubles,thenthecardiacoutputdoublesifthestrokevolumeremainsconstant.Thismeansthattherateofpumpingintothesamebarrelshouldalsodouble.Theoveralleffectisthatthebarrelwouldfillinonlyhalfthetimecalculatedinquestion6.b.Byusingthesampledataprovidedin6.a.and6.b.,thebarrelwouldfillin25minutes.


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Practice, page 13

7. Yourdiagramshouldbesimilartothefollowing.

superior vena cava from upper body

inferior vena cava from lower body

aorta to lower body

pulmonary artery to right lung

pulmonary artery to left lung pulmonary artery

pulmonary veins from right lung

pulmonary veins from left lung

semilunar valve

right atrium

aorta

left atrium

rightventricle

left ventricle artrioventricular

valve

semilunar valve

artrioventricular valve

septum

to lo

w

er body to

u

pper body

1

6

2

4

3

5

the Human Heart

Practice, page 16

Resultsforquestions8and9willvarydependingonstudentage.Sampledatafora17-year-oldstudentfollows.

8. Findyourmaximumheartratebysubtractingyouragefrom220.

220-17=203beatsperminute


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10. Aspeoplegetolder,theirtargetheartrateswilldecreaseforeachcategory.

1.1 Questions, page 19

Knowledge

1. Beginningwiththevenacavae,theorderofthestructuresofthecardiovascularsystemthroughwhichbloodflowsisasfollows:venacavae,rightatrium,rightventricle,lungs,leftatrium,leftventricle,aorta,andbody.

2. a. IV Thepulmonaryveinsreceiveoxygenatedbloodfromthelungs. b. II Theaortasendsoxygenatedbloodtothebody. c. V Thesemilunarvalvepreventsthebackflow

ofbloodintotheheart. d. VI Theseptumseparatestherightandleft

halvesoftheheart. e. I Thevenacavaecollectsdeoxygenated

bloodfromthebody.

I

II

III

IV

V

VI

9. Studentswillusetheiranswersfromquestion8tofinishthistable.

Your target Heart rate

Personal Health Goal Heart rate

50% of 203 bpm = 102 bpm

maintain fitness level

60% of 203 bpm = 122 bpm

increase fat burning or weight loss

70% of 203 bpm = 142 bpm

increase cardiovascular endurance

80% of 203 bpm = 162 bpm


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applying Concepts

3. a. strokevolume mL/beat

mL /beat L mL

L/b

=

= ¥

=

100

100 11000

0 100. eeat

heartrate beats/minute rest

heartrate beats/m

= ( )=

50

115 iinute lightexercise

heartrate beats/minute high-inte

( )=180 nnsityexercise

cardiacoutput

( )= ?

atrest: cardiacoutput strokevolume heartrate

Lbeat

= ( ) ¥ ( )

= ¥0 100 50. beats

L/min

( )

=min

.5 0

Thecardiacoutputis5.0L/minfortheathleteatrest.

lightexercise: cardiacoutput strokevolume heartrate

L

beat

= ( ) ¥ ( )

=( )

¥0 100. 1115

11 5

beats

L/min

( )

=min

.

Thecardiacoutputis11.5L/minfortheathletedoinglightexercise.

high-intensityexercise: cardiacoutput strokevolume heartrate

L

beats

= ( ) ¥ ( )

=( )0 100.

¥¥( )

=

180

18 0

beats

L/min

min

.

Thecardiacoutputis18.0L/minfortheathletedoinghigh-intensityexercise.

b. Regularcardiovascularexerciseincreasestheelasticityofthehearttissue—thisgivestheheartagreatercapacitytoexpandand,therefore,alargerstrokevolume.Sincethestrokevolumeislarger,anincreasedvolumeofbloodispumpedtothebodyduringeachoftheheart’scycles,sotheathlete’sbodycangetthenecessaryamountofbloodwithfewerheartbeats.

Aninactivepersontendstohaveaheartwithlesselastictissue,sothishearthasadecreasedabilitytoexpandand,therefore,areducedstrokevolume.Thisreductioninbloodvolumepumpedtothebodyduringeachoftheheart’scyclesmeansthatittakesmoreheartbeatseveryminutetosupplythebodywiththerequiredamountofblood.


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Practice, page 23

11. a. Partsofthecirculatorysystemthatcorrespondtoacommunity’swaterpipes,sewagepipes,pump,andwaterare,inorder,thearteries,veins,heart,andblood.

b. Onelimitationisthatthecirculationofbloodinthehumanbodyisaclosedsystembecauselargeamountsofblooddonotnormallyenterandleavethesystem.Acommunity’swatersystemisnotaclosedsystem.Cleandrinkingwatercomesfromtheenvironmentandthenreturnstotheenvironment.Inotherwords,manycommunitiesmayusethesameriversystemasawatersource,butundernormalcircumstancesmanypeopledonotgettheirbloodfromthesamecommonsource.

Anotherlimitationoftheanalogyisthatthebodydoesnothavetheequivalentofawatersystem’sreservoir.Thereisnoplaceinthebodythatcontainsavastpoolofbloodthatcanbestoredovermanymonths.

12. a. Thepulmonaryarteriescarryoxygen-poorbloodfromthehearttothelungs. b. Theaortaisthebody’slargestartery. c. Thecoronaryarteriescarryoxygen-richbloodfromtheaortatonourishthehearttissues. d. Thepulmonaryveinscarryoxygen-richbloodfromthelungstotheheart. e. Thevenaecavaecarryoxygen-poorbloodfromthebody’stissuestotheheart.

13. Arteriesalwayscarrybloodawayfromtheheartandveinsalwayscarrybloodtotheheart.Thisisalwaystrue.However,itisnotalwaystruethatarteriescarryoxygen-richbloodandveinscarryoxygen-poorblood.Thepulmonaryarteriescarryoxygen-poorbloodfromtherightventricletothelungs.Thepulmonaryveinscarryoxygen-richbloodfromthelungsbacktotheheart.

14. Itisimportantforthewallsofcapillariestobethinsothatoxygenandothersubstancesneededbycellscandiffusefromthebloodtothetissuecells.Thethinwallsalsoallowcarbondioxideandwastematerialstodiffusefromthetissuecellsintotheblood.

Practice, page 24

15. a. vein b. capillary c. venule d. arteriole e. artery

16. Thecorrectorderisartery,arteriole,capillary,venule,andvein.

17. Ifinactivitymeansthatthemusclesarenotregularlycontracting,thentheveinswillhaveahardertimemovingbloodbacktotheheart,whichmayresultinimpairedcirculation.

18. Thelower-legveinsarethefarthestawayfromtheheartandthebloodinthemhasthelongestwaytotravelbacktotheheart.Gravityalsoplaysaroleheresincewhenyouarestanding,thepathfromthefeettotheheartisstraightup—thisisoppositetothedirectionthatgravitynaturallytendstopullmatter.

Itfollowsthatbloodismorelikelytobesloweddownorpoolinthelowerlegs.Thevalvesinthelegs’veinsarethereforeunderthegreatestamountofstressandmostoftenbecomelesseffective.Thiscanleadtovaricoseveins.


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19. Forastandingperson,thevalvesinthelegveinsareworkingagainstgravity.Ifpeoplespendmuchoftheirdaysontheirfeet,itmeansthatbloodispoolinginthelegsforalongeramountoftime.Thiscanputextrastressonthesevalves.Elevatingthefeetattheendofalongperiodofstandingreducessomeoftheforcefrompooledblooddrawndownwardbygravity.Raisingthefeetalsotakespressureoffthevalves,whichreducestheriskofdevelopingvaricoseveinsorsufferingdamagefromthatcondition.

Conclusion

4. Bloodflowsfromthehandtowardtheheart.Ifbloodispushedagainstthisflow,itpoolsintheveinsatcertainplaces.Theseplacescorrespondwiththevalves.

Practice, page 29

20. a. Thevalueof138issystolicpressure.Thisispressurecreatedbybloodpushingagainstthewallsofthebrachialarterywhentheheart’sventriclesarecontracting.Theelasticfibresinthearterywallsstretchandexpandslightlyinresponsetothispressure.

Whentheheart’sventriclesarerelaxed,aresidualpressureismaintainedasarteriesattempttoreturntotheirpreviousshapebetweencontractionsoftheventricles.Thisdiastolicpressureisrepresentedby96.

b. Theunitforeachofthesepressuresismillimetresofmercury.

c. Bloodpressurevalueshigherthan140/90arecategorizedashighbloodpressurebecausethesevaluesareabnormallyhigh.Thisoftenindicateshealthproblemsthatneedtobetreatedbyaphysician.Sincethevaluesfromtheautomatedmachineareclosetohighbloodpressurelevels,itwouldbewisetomakeanappointmentwithafamilydoctorandhavethesevaluesconfirmed.Itmaynotnecessarilybecauseforconcernbecausethehighvaluescouldbeduetootherfactorsthatmayhavetemporarilyraisedbloodpressurevalues,suchastightclothingaroundthearmwhenthetestwastaken;anxietyornervousness;oreatingordrinkingsomething.

21. Thesourceofresidualpressureistheslightcontractionofthearteries’elasticwallsastheyattemptto

reboundfromtheslightstretchingcausedbythepreviousheartbeat.

22. Severalfactorscausetheblood’sspeedtodropasitpassesthroughthecapillaries.Thetotalcross-sectionalareaofvesselscarryingblooddramaticallyincreasesasthebloodpassesfromarteries,intoarterioles,andthenintocapillarybeds.Sincethereisamuchlargeropeningfortheincomingbloodtopassthrough,theblooddoesnothavetoflowasfastfortheoutputtomatchtheinput.Asimilareffectcanbeobservedifastudentplaceshisorherthumbovertheendofagardenhoseandthenreleasesthethumbtocreatealargeropening.Inthiscase,watercomesoutofthehoseatareducedspeed.ThetoptwophotosfromFigureA1.xxcanbecheckedforfurtherdetails.

Anothereffecthastodowithresistancetothebloodflow.Capillariesaresotinythatbloodcellshavetopasssinglefilethroughthesmallestofthesevessels.Thiscausesadropinpressurethatresultsinaslowingdownofthebloodflow.


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Knowledge

1. Thefollowingtablecomparesarteries,veins,andcapillaries.

arteries Veins Capillaries

description of vessel walls thick-walled and elastic fibre

thinner walls with no elastic fibres

thinnest walls possible—only one cell thick

direction of vessel blood flow in relation to heart

away from heart toward heart from arteries and arterioles, through capillaries, to venules and veins, and back to heart

blood oxygen level in vessel

relatively high level relatively low level higher level at end close to arteries and a lower level at end close to veins

colour in a circulatory system diagram

red blue red at end close to arteries and blue at end close to veins

blood pressure in vessel high pressure very low pressure pressure decreases as blood moves from the end closest to arteries to end closest to vein

valves present no yes no

pulse present yes no no

applying Concepts

2. a. Peoplewithdiabeteswouldnolongerhavetoinjectthemselveswithinsulin.Usinganinhalerwouldbeamuchlesspainfulandinvasivedeliverysystem,andtherewouldbelesschanceofinfectionfrompoorsanitationattheinjectionsiteorscarringfromrepeatedinjections.Intermsofdisposalandsafety,itismuchmoreconvenienttocarryaroundaninhalerthanitistocarrysyringes.

b. Thepathfromfatundertheskinisasfollows:afatcapillaryundertheskin;avenule;avein;thevenacava;therightatrium;therightventricle;thepulmonaryarteries;thelungs;thepulmonaryveins;theleftatrium;theleftventricle;theaorta;severalarteries;anarteriole;andendatacapillarynexttoatargetcellintheliver.

c. Inhaledinsulinwouldtakethefollowingpathfromthelungstoatargetcellintheliver:thelungs;thecapillariesandvenulesoflungtissue;thepulmonaryveins;theleftatrium;theleftventricle;theaorta;severalarteries;anarteriole;andthentoacapillarynexttothetargetlivercell.

d. Theinhaleddeliverysystemwouldbefasterbecausetheneededchemicalwouldnothavetofirsttravelthroughthede-oxygenatedpartsofthecirculatorysystem.Thisquickerdeliverywouldbeanadvantageoverthehypodermicdeliverysystem.


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3. Factorsthatcancauseaperson’sbloodpressuretoincreaseincludeastrongercontractionoftheheart,ahigherheartrate,andalossintheelasticityofthearteries.Higherbloodpressurereadingscanalsobeattributedtoanxietylevel,exercise,agreaterthannormalamountofbloodinvessels,viscosity(thickness)oftheblood,chemicalssuchascaffeineorepinephrine,kidneydisease,oranarrowingofthebloodvesselsduetoapoordiet.

4. Ifanarteryiscut,thegreaterpressureinanarterymeansthatthebloodflowsoutmorequicklyandforcefullythanitwouldinavein.Itfollowsthatthereisagreaterriskofbloodlosswithacutarterythanthereiswithacutvein.

5. Thefollowingillustrationisasketchofacapillarybed.

blood flow

artery

arteriole

Capillary Bedcarbon dioxide and other waste

materials diffuse from tissuecells into blood

oxygen and othermaterials diffuse fromblood into tissue cells

valve

vein

venule

6. Contractingmusclesinthelowerlegshelptomassagethebloodinthelowerlegsbacktowardtheheart.Oncethelegmusclespushthebloodintheveins,thevalvesareabletodirectthisblood.

Practice, page 36

23. sample of bloodprior to placement

in centrifuge

sample of bloodafter removal

from centrifuge

centrifuge

plasma

platelets,white blood cells

red blood cells


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24. a. Plasmacomprisesabout55%ofbloodvolume. b. Redbloodcellsmakeupalmost45%ofthetotalvolumeofblood. c. Plateletsandwhitebloodcellscompriselessthan1%ofthetotalvolumeofblood.

Practice, page 38

25. a. Inconditionsofextremefatigue,cancerpatientsbenefitfromatransfusionofredbloodcells.

b. Spinningasampleofwholebloodinacentrifugecouldseparatethewholebloodintoredbloodcellsandothercomponents.

26. a. Whitebloodcellsonlylivefrom13to20days,whileredbloodcellsliveabout120days.Therefore,morewhitecellsneedtobemadebecausetheydon’tlivenearlyaslongasredcells.

b. Whitebloodcellsacttodefendthebodyagainstdiseasesandotherforeigninvaders.Mostdisease-causingagentstendtobefoundinthefluidspacesbetweentissuecells,sothisisalsowherewhitebloodcellstendtobe.Sinceabloodtestonlycountsthenumberofwhitebloodcellsinthebloodstream,thewhitecellsoutsideofthebloodstreamarenotincluded.

Practice, pages 40 and 41

27. ThebloodcomponentsthatbestcorrespondtobagsI,II,andIIIare,respectively,redbloodcells,plasma,andplatelets.

28. Ifburnvictimsarehighlysusceptibletodehydration,thebloodcomponentthatbestaddressesthisproblemisplasma,duetoitshighwatercontent.

29. Topreventuncontrollableinternalbleeding,plateletsareoftengiventocancerpatientsaftertheyreceiveradiationtherapy.

30. Everytimeyoudonatewholeblood,thisproductcanbeputinacentrifugeandseparatedintoredbloodcells,plasma,andplatelets.Eachoneofthesethreecomponentscanthenbeusedtohelpanotherpersonandpossiblysavealife.


Knowledge

1. a. Thefourcomponentsofbloodfrommostabundanttoleastabundantareplasma,redbloodcells,whitebloodcells,andplatelets.

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b. Thefollowingdiagramillustrateseachcomponentofquestion1.a.

red blood cell

white blood cell

platelet

plasma

2. a. Slidenumber6fromthepatientwithneutrophiliahasmorewhitebloodcellsthanthepatientwithhealthyblood.

b. Thepatientwithneutrophiliaislikelysufferingfromaninfection.

applying Concepts

3. Carbonmonoxidehasamuchgreateraffinityforhemoglobinthandoesoxygen,socarbonmonoxidewillpreferentiallybindtohemoglobinandformastablebond.Asaresult,ifyouinhaleevenlowconcentrationsofcarbonmonoxide,morehemoglobincombineswithcarbonmonoxidethandoesoxygen.Ifcarbonmonoxideistakingtheplaceofoxygenontheredbloodcells,thatmeansthatthebloodcannottransportneededoxygentothebody’scells.Apersoncouldsuffocateeventhoughheorsheisabletobreathenormally.

4. Anticoagulantsthatthinbloodmakeiteasierforbloodtoflowthroughdamagedorconstrictedbloodvessels.

5. a. Havingimproperlyfunctioningwhitebloodcellsmeansthatthepersonisnotabletofightoffdisease-causingorganisms.

b. Atransplantofhealthybonemarrowmeansthathealthyandnormallyfunctioningwhitebloodcellswillbeproduced.

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6. Atthetimethistextbookwaspublished,theCanadianBloodServicesusesthesecriteriatodetermineeligibilityfordonatingblood:

• Youmusthaveidentificationcontainingyourfullnameandsignatureorfullnameandphotograph.

• Youmustbeatleast17yearsold.

• Youmustweighatleast50kg(110pounds).

• Ifyouhavepreviouslydonatedblood,atleast56daysmusthavepassedsinceyourlastdonation.

• Youmustbeingoodhealthandfeelingwell.Youshouldhavehadsomethingtoeatandbewellrested.Ahemoglobintestonyourbloodwillbedoneattheclinic,andasampleofyourbloodmustpassthistest.

• Atthetimeofthedonation,youwillbeaskedanumberofquestionsrelatedtoyoursuitabilitytogiveblood.Thesequestionswillincludewhetheryoucurrentlyhaveacold,ifyouhavebeentothedentistrecently,orifyouhaveanybodypartpierced.

Practice, page 43

31. ItisnowknownthatscurvyisduetoinsufficientamountsofvitaminCinpeople’sdiet.ThemainsourceofvitaminCfortheearlyEuropeanswasfreshfruitandvegetables.Atthattimeitwasraretofindtheseitemsaboardthewoodensailingshipsthatventuredintonorthernwaters.

32. Inuitpeopleneversufferedfromscurvybecausetheirdietsincludedmaktaaq,asnackconsistingofwhaleskinwithanattachedthinlayerofblubber.WhaleblubberisarichsourceofvitaminC,sothisfoodwouldhelppreventscurvy.

33. Inuitpeopleknewthatmaktaaqandmanyotherfoodsintheirtraditionaldietpromotedgoodhealth.Althoughthetermvitamin Cwasnotintroduceduntilthetwentiethcentury,thecollectiveexperiencesfromthousandsofyearsofinteractionwiththeArcticenvironmentallowedInuitpeopletodevelopanunderstandingofwhatfoodcombinationskeptpeoplehealthy.ThisinformationwouldhavebeenveryhelpfultotheearlyEuropeanArcticexplorers.Thesolutionforavoidingscurvywasathand,especiallysincemanyoftheseearlyEuropeanswerewhalersandvitaminC-richwhaleblubberwaslikelyalreadyaboardtheirships.

Practice, page 45

34. Thesandwichfillingcontainingpeanutbutterwouldbetheonlyonetobefreeofcholesterolbecausealltheotherfillingscomefromanimalsources.

35. a. Theunitmmol/Lmeansmillimolesperlitre,whichisaunitofconcentration.

b. PersonBhasthehealthiercholesterollevels.OnereasonforthisisthatthispersonhaslowerlevelsofLDLcholesterol.Low-densitylipoproteincarriescholesterolfromthelivertothebody’stissuecellsandintheprocesscanaddtotheunhealthyaccumulationofcholesterolontheinsideofarteries.

AnotherreasonisthatpersonBhashigherlevelsofHDLcholesterol.High-densitylipoproteinscoursthebloodstreamforcholesterolandthentransportsthecholesteroltothelivertoeliminateitfromthebody.HigherlevelsofHDLmeansthatmorecholesterolisbeingeliminatedfromthebody.


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Practice, page 46

36. Cardiovasculardiseasereferstoawiderangeofdisordersthataffecttheheartand/orbloodvessels.Examplesincludecoronaryheartdisease,strokes,andvaricoseveins.Atherosclerosisisanotherexample.Thisdiseaseinvolvesdepositsofcholesterolandotherfattysubstancesbuildingupontheinsideliningofanartery.Ifthearteryisacoronaryartery,thisdisordercanleadtocoronaryheartdiseaseandaheartattack.Ifthearteryisonethatsuppliesthebrainwithblood,thedisordercanleadtoastroke.

37. a. Plaquecandevelopaharderoutersurfacethatisrigidandinflexible.Sinceplaqueisattachedtotheinsideofanartery,thearterylosesitselasticity.

b. Astheleftventriclecontracts,bloodispushedthroughtheaortatotherestofthebody.Thesystolicbloodpressurethatresultspushesonthewallsofhealthyarteries,causingthemtoslightlyexpand.Whentheventriclesrelax,thehealthyarteriescontractslightlyastheyreturntotheirinitialshape.Theresidualpressurethatresultsisresponsibleforthediastolicpressure.

Arterieslinedwithcholesterolandplaqueareunabletoslightlyexpandandcontract.Thiswouldhavetheeffectofraisingthevaluesofthesystolicpressureand,therefore,theresidualdiastolicpressure.

38. Asplaquebuildsupontheinsideofarteries,theouterplaquesurfacecanbecomehardandrigidwitharoughsurface.Crackscandevelopintheplaque.Sinceplateletsrupturewhentheypassoveraroughsurface,thepresenceofplaquemakestheclottingprocessmorelikely.

Practice, page 49

39. Onlyabout25%ofcholesterolinthebloodstreamismadeupofcholesterolabsorbedfromfood.Reducingthecholesterolcontentoffoodeatencanonlyinfluenceone-quarterofthetotalcholesterolinaperson’sbloodstream.

40. a. Thebreakfastdescribedincludesbaconandbutter,whicharebothhighinsaturatedfat.Theegghassomesaturatedfat,butitisasignificantsourceofdietarycholesterol.Overall,thismealhasanegativeeffectonbloodcholesterollevels.ThesaturatedfatinthebaconandthebuttertendstoelevatethelevelsofLDLcholesterol.

b. Thedeep-friedonionringsandthedonutarelikelybothsourcesoftransfats.TransfatstendtoraisethelevelsofLDLcholesterolandlowerHDLcholesterollevels.Theoveralleffectisasignificantriseinbloodcholesterollevels.

Althoughthelargesoftdrinkdoesnotcontributetobloodcholesterollevels,itisasignificantsourceofsugar.TheexcessiveconsumptionoffoodsrichinsugarhasbeenlinkedtoobesityandalsototypeIIdiabetes.BothobesityandtypeIIdiabeteshavebeenshowntoincreasetheriskofheartattack.

c. Tunaisasourceofpolyunsaturatedomega-3fattyacids,whileoliveoilisasourceofmonounsaturatedomega-9fattyacids.BothofthesesubstancestendtolowerLDLcholesterollevelsandraiseHDLcholesterollevels,resultinginanoverallpositiveeffectonbloodcholesterollevels.Thismealisthehealthiestchoiceofthethreemealspresented.

41. Fatisanimportantnutrientneededtomakehealthycellmembranes,toproperlydevelopthebrainandnervoussystem,andtoproducehormone-likesubstancesthatregulatebodyfunctions(e.g.,bloodpressure).Adietthateliminatesallfoodscontainingfatisveryunhealthybecauseanessentialnutrientisdenied.

Iftheonlysourceoffatisanoccasionalbingeoffriesandgravy,thenthebodyisstilldeniedessentialfattyacidsbecausethissnackisrichinsaturatedfatsandtransfats,butnotomega-3andomega-6essentialfattyacids.Inaddition,thefriesandgravywillalsocauseanunhealthyspikeinbloodcholesterollevels.


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Practice, page 52

42. a. Theproblemaddressedbyhavingpeopleincreasethemarinesourcesofomega-3fattyacidsintheirdietsisthehighincidenceofcardiovasculardiseaseinthegeneralpopulation.CardiovasculardiseaseisthenumberonecauseofdeathinCanada.

b. Severalunintendedproblemsmightarisefromthistechnologicalsolution.Iflargenumbersofpeopleinthedevelopedworldbegantoeatfishasastaplepartoftheirdiet,therecouldbeanegativeeffectonboththemarineenvironmentandoceanecosystems.Theworld’soceansarealreadystressed,andawidespreadchangeineatinghabitscouldhaveanegativeeffectonfishstocks.

Anotherproblemisthatpeoplecouldgetthemessagethatalltheyhavetodoischangetheireatinghabits,attheexclusionoftheotherriskfactorsforcardiovasculardisease.Evenifeatinghabitschange,therewillbelittlechangeintheincidenceofcardiovasculardiseaseifpeoplecontinuetoliveinactivelifestyles.

c. Thedepletionoffishstockscouldbesolvedbyfindingotherwaysofaddingmarineomega-3fattyacidstopeople’sdiets.Perhapsanimalfeedcouldbesupplementedwithfishoiltoaugmenttheomega-3fattyacidcontentineggs,milk,andmeat.However,makingdramaticchangestowhatisfedtoanimalsisariskybusinessthatcanhaveunpredictableeffects—outbreaksofBovineSpongiformEncephalopathy(BSE)incattleareacaseinpoint.

Anothersolutionmightbetofindamarineplantthatcanproducethemarineomega-3fattyacidsratherthanalwaysrelyinguponfish.Themarineplantscouldbeharvestedandthenincorporatedintootherfoodproducts.Again,ifthisweretobedoneonalargescale,sustainabilityandenvironmentaleffectsontheoceanswouldhavetobeconsidered.Anotherpossibilitywouldbetogeneticallyengineerlandplantstoproducethemarineomega-3fattyacids.Again,thistechnologicalfixhasitsownrisks.

43. a. Thedefinitionfortraditionalecologicalknowledgeisasfollows.

Traditionalecologicalknowledgeisknowledgeacquiredoverthousandsofyearsthroughapeople’sdirectcontactwiththeenvironment.It’sadynamicapproachtodevelopingnewunderstandingsofhumaninteractionswiththeenvironmentthatfocusesontheinseparablerelationshipbetweenland,resources,andculture.

Thelastpartofthisdefinitionimpliesaholisticapproachthatgoesbeyondtheminutiaeofthedetailstoincludeconnectionsbetweenland,resources,andculture.

b. Abenefitofintegratingscientificresearchwithtraditionalecologicalknowledgeisthattwodifferentpointsofviewcanbeusedtosolveproblems.Thescientificpointofviewbringsmethods,tools,andtechnologiesofWesternscience,whiletraditionalecologicalknowledgebringsthousandsofyearsofhumanexperiencewiththeenvironment,aswellasaviewpointthatstressesconnectionstothewidercontextofcultureandotherhumandimensions.


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44. Thefollowingisasampleofhowyoumayhavecompletedthequestionnaire.

CardiovascularDiseaseRiskQuestionnaire

Readthefollowinglifestyleandfamilyhistorystatementsthatrelatetocirculatorydiseases.Placeacheckmarknexttotheonesthatapplytoyou.

❏✓ 1. Ihaveafatherorbrotherwhohadaheartattack,astroke,oraheartprocedure(e.g.,angioplasty,coronarybypass,oranotherexample)beforeage55.

❏ 2. Ihaveamotherorsisterwhohadaheartattack,astroke,oraheartprocedure(e.g.,angioplasty,coronarybypass,oranotherexample)beforeage65.

❏✓ 3. IsmokeorIamexposedtosecond-handsmoke.

❏ 4. Mybloodpressureisgreaterthan140/90mmHg.

❏ 5. Ihavediabetes.

❏✓ 6. Iamphysicallyinactiveandrarelyengageinaerobicexerciseactivities,suchascycling,jogging,swimming,andsoccer.

❏ 7. Iamunderhighstress.

❏✓ 8. Iam20ormorepoundsoverweight.

❏✓ 9. Mydietcontainsalotoffoodshighinsaturatedfats,transfats,andcholesterol,suchasredmeats,wholemilk,cream,butter,cheese,fastfoods,andfriedfoods.


Knowledge

1. a. angina b. stroke c. septaldefect d. atherosclerosis e. plaque f. heartattack g. aneurysm

applying Concepts

2. Thepatientwouldmostlikelybeaskedifshesmokesandeatsalotofhighsaturatedfatandhighcholesterolfoods.Shemaybeaskedhowmuchandwhatkindofexerciseshedoes,orifsheisunderalotofstress.Suggestionsforreducingtheriskofdevelopingacardiovasculardiseaseincludequittingsmoking,havingamorehealthydiet,andexercisingregularly.

3. a. Ifsomethingisstuckinoneofthepipesandcausessomehomestolosewaterservice,thissituationiscomparabletoabloodclotinthehumancirculatorysystem.

b. Ifthewaterpressureissohighthatastrainisputonthepipes,causingthepipestoleak,thesituationiscomparabletohighbloodpressureorhypertensioninthehumancirculatorysystem.

c. Afaultyvalveinthewaterpumpiscomparabletoaheartvalvedefectinthehumancirculatorysystem.


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4. Fataccountsfor0.74%oftheservingmassformoosemeat.Forbeef,22.55%oftheservingmassisfat.

5. Fatisaveryconcentratedformoffoodenergy.Thefactthatbeefisnearlyone-quartersaturatedfataccountsforitshigherenergycontent.

6. Saturatedfataccountsfor0.22%oftheservingmassformoosemeat.Forbeef,9.16%oftheservingissaturatedfat.

7. Duetoitslowsaturatedfatcontent,moosemeathasahealthiereffectonbloodcholesterollevelsthanbeefdoes.BeefhasagreatertendencytoraiseLDLcholesterollevelsduetoitshighsaturatedfatcontent.

8. Thefollowingcalculationsshowthepercentageoftotalfatthatisduetoomega-3andomega-6fattyacidsinmoosemeatandbeef.

MooseMeat

• omega-6fattyacid

m

mO

TF

g

g6

0 14

0 74

===

.

.

% ?

% %

.

.%

%

=ÊËÁ

ˆ¯̃

¥

= ÊËÁ

ˆ¯̃

¥

=

m

mO

TF

gg

6 100

0 140 74

100

19

Ofthetotalfatinmoosemeat,19%iscomposedofomega-6fattyacids.


m

mO

TF

g

g3

0 03

0 74

===

.

.

% ?

% %

.

.%

. %

=ÊËÁ

ˆ¯̃

¥

= ÊËÁ

ˆ¯̃

¥

=

m

mO

TF

gg

3 100

0 030 74

100

4 1

Ofthetotalfatinmoosemeat,4.1%iscomposedofomega-3fattyacids.

Beef


m

mO

TF

g

g6

0 57

22 55

===

.

.

% ?

% %

..

%

. %

=ÊËÁ

ˆ¯̃

¥

= ÊËÁ

ˆ¯̃

¥

=

m

mO

TF

gg

6 100

0 5722 55

100

2 5

Ofthetotalfatinbeef,2.5%iscomposedofomega-6fattyacids.


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m

mO

TF

g

g3

0 23

22 55

===

.

.

% ?

% %

..

%

. %

=ÊËÁ

ˆ¯̃

¥

= ÊËÁ

ˆ¯̃

¥

=

m

mO

TF

gg

3 100

0 2322 55

100

1 0

Ofthetotalfatinbeef,1.0%iscomposedofomega-3fattyacids.

9. Themoosemeathasagreaterpercentageofomega-6andomega-3fattyacidsinitstotalfatcontent.ThismeansthatthemoosemeathasabetterchanceofraisingHDLcholesterollevelsandloweringLDLcholesterollevels.

10. MoosemeathaslesssaturatedfatthatwillraiseLDLlevelsandagreaterpercentageofitsfatconsistsofpolyunsaturatedfattyacidsthatwilllowerLDLlevelsandraiseHDLlevels.Overall,moosemeatisagoodchoiceforreducingriskfactorsassociatedwithcardiovasculardiseases.

Practice, page 57

45. Thefollowingtablecomparestherolesandpartsofacastlefortresstothepartsoftheimmunesystem.

Part of Immune system role Part of a Castle

skinprotective barrier that keeps

out invaderscastle walls

cilia and mucous secretionstrap invaders as they try

to enterguarded entrances and moat

plateletspatch holes in protective

barrierstonemasons

white blood cellsdestroy invaders who make it

past first line of defencedefensive army


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score scoring Description

standard of excellence (4 marks)

The response is well organized and addresses all the major points of the activity. Relevant scientific, technological, and/or societal concepts and examples are identified and interrelationships are explicit. The descriptions and/or explanations of these concepts are correct, well organized, and reflect thorough understanding and logical consistency of thought. The student uses complete sentences that make effective use of scientific vocabulary. When appropriate, suitable metaphors, similes, diagrams, and/or sketches are used to illustrate descriptions and/or explanations.

(3 marks)

The response is organized and addresses most of the major points of the activity. Relevant scientific, technological, and/or societal concepts and examples are identified and interrelationships are evident. The descriptions and/or explanations of these concepts are organized and reflect correct understanding. The student uses complete sentences that employ correct scientific vocabulary. When appropriate, suitable diagrams or sketches are used.

acceptable standard (2 marks)

The response addresses most major points. Relevant scientific, technological, and/or societal concepts and examples are identified, and interrelationships are shown. The descriptions and/or explanations of concepts may be disorganized but demonstrate correct understanding. The student uses complete sentences but is inconsistent in the use of appropriate scientific vocabulary, diagrams, and sketches.

(1 mark)

The response addresses few major points. Concepts are identified, but interrelationships are not evident. The student superficially describes concepts in sentences, but organizational skills, scientific vocabulary, diagrams, and sketches are minimal.

(0 marks)The response does not address any of the major points of the question at an appropriate level for a 30-level course.

rubrIC for KnoWLeDGe

Practice, page 62

46.

type of Pathogen Defining Characteristics example of a Disease Caused

by this type of Pathogen

protozoansmicroscopic, single-celled organisms with a nucleus—most can only divide within a host organism and cause disease

Malaria is caused by protozoans that infect red blood cells.

fungiorganisms that absorb food directly through cell walls and do not conduct photosynthesis

Athlete’s foot is a fungal infection.

bacteriamicroscopic, single-celled organisms that don’t have their genetic material contained in a nucleus

Salmonella bacteria cause food poisoning.

virusesextremely tiny particles consisting of a protein coat enclosing genetic material; viruses are not considered to be living organisms

Influenza is caused by a virus.

MICrosCoPIC PatHoGens


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47. Thereasonthatvirusescouldnotbeseenthroughalightmicroscopeorisolatedusingfiltersisthattheseparticlesareextremelysmall.Sincetheyareonlyabout1/100thesizeofabacterium,theyaredifficulttoobserve.

Practice, page 66

48. a.andb.

Theanswerstothesequestionscanbefoundontheillustrationlabelled,“OverviewofImmuneResponse”inthetextbook.

49. a.andb.

sketch of Components name of Components

role(s) in the Immune response

Antigenallow white blood cells to recognize foreign invaders

Macrophage

patrol and engulf foreign disease-causing organisms and display antigens on their cell membranes

Helper T-cellidentify antigens of foreign invaders and signal response of B-cells and killer T-cells

tHe IMMune resPonse—CoMPonents anD roLes


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B-cellproduce specific antibodies to antigens

Antibody attach to antigen of foreign material

Killer T-celldestroy cells that have become mutated or infected with viruses

Memory B-celland

Memory T-cell

remain after invading organism has been destroyed to allow for quicker response to future encounters with that antigen

Suppressor T-cell signal for immune response to end

Practice, page 67

50. Althoughmostofyouwillhaveaccesstoyourownvaccinationrecords,someofyoumaynothavereceivedvaccinationsduetoreligiousorotherreasons.

�0Science 30: Unit A Suggested Answers

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Practice, page 69

51. AlthoughitwasverybeneficialtosocietyforJennertotestouthistheoryonahumansubject,JamesPhippscouldhavediedfromthesmallpoxvirus.ThiswasnotanethicalpracticesinceJamesPhippswasnotoldenoughtoconsenttothistreatment.

52. Thesepeoplewereparticularlysusceptibletothesmallpoxvirusbecausetheyhadneverbeenexposedtothisdisease-causingorganism,sonoonehadmemorycellstomakeantigens(naturalimmunity)againstsmallpox.Thismeansthattheviruscouldspreadveryquicklythroughthepopulation.

53. a. Themajorconcernwithkeepingtheviralstockisthatsincenoonegetsvaccinatedanymore—duetothedangerofhandlingthevirusandthedangerous(evenfatal)sideeffectsofthevaccination—areleasedviruswouldcausemajorsicknessinanunvaccinatedpopulation.Somepeopleworrythattheviruscouldevenbeusedasabioterrorismweaponifitwaspurposelyreleasedintoapopulation.

b. Keepingthesestocksisbeneficialbecausetherearespecimenstostudyandtoproduceavaccinefrom.Ifavirusisreleasedinabioterrorismact,thenalaboratorysampleofthesmallpoxvirusisavailabletobeexamined.


Knowledge

1. a. Malariaisavector-bornediseasethatgetsintothebodyviaamosquitothatpuncturestheskinbarrier.Malarialivesinsideredbloodcells,whichmakesitdifficultforwhitebloodcellstodetectitasaforeigninvader.

b. HepatitisCisablood-bornediseasethatisusuallytransmittedthroughtheskinbarrierthroughthesharingofneedlesorbysexualintercourse.

c. Tuberculosisisanairbornediseasecausedbyinhalingdropletsfromaninfectedperson’slungs.

d. Salmonellaisafood-bornediseasethatcomesfromeatingimproperlycookedfoodorfoodcontaminatedbyfeces.Stomachacidisunabletokillalltheinvadingorganisms.

2. Althoughautoimmunediseasesandinfectiousdiseasescanbothmakeyousick,anautoimmunediseasecannotbecaughtbecauseitdoesnotcomefromaninvadingpathogenasdoesaninfectiousdisease.Anautoimmunediseaseoccurswhenaperson’swhitebloodcellstargetandattacksomeorallofthebody’scells.Autoimmunediseasescannotusuallybecured,sothisconditionoftenlastsfortheremainderofaperson’slife.


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3. Atablefollowscomparingthesimilaritiesanddifferencesbetweenbacteriaandviruses.

similarities Differences

Both cause sickness. Bacteria can be treated by antibiotics.

Both are too small to see with the naked eye. Viruses are much smaller than bacteria.

Both must break through the body’s first line of defenses (e.g., skin, mucus) to make you sick.

Viruses are considered non-living.

You can be vaccinated against both types of pathogens.

Bacteria reproduce by splitting in two.

Both come in a variety of shapes.Some bacteria can be harmless or even beneficial, while all viruses cause disease.

4. Youcancheckyourworkbyreplayingtheappletandcomparingtheinformationpresentedwiththeinformationpresentedinthetextbook.OneminordiscrepancyisthatthevideoshowsthekillerT-cellactuallyattackingthemembraneoftheinvadingpathogen—thecurrentunderstandingisthatkillerT-cellsdestroytissuecellsthathavetheantigensofthepathogenontheircellmembranes.

applying Concepts

5. a. Ifapersonwithhemophiliahasbloodthatdoesnotclotproperly,cutsorbreaksintheskinwillberepairedandpluggedmoreslowly.Thisdelayinrepairingtheskinincreasesthechancesfordisease-causingorganismstocrosstheskinbarrier.

b. Withouttheskinbarrier,bodytissueswillbeexposedtodisease-causingpathogensthatcanmoreeasilyenterthebloodstream.

c. IfsomeonewithHIVhasT-cellsdestroyedbythevirus,thendiseasesthatenterthebodycanonlybeeatenbythemacrophages.Therewillbenodirectedattackwithspecificantibodiestotargettheseinvaders.Unfortunately,peoplewithHIVcandiefromdiseasesandrarecancersthatthebodycouldnormallydealwithifT-cellswerepresent.

6. a. Whenvaccinationsaregivenatbirth,memorycellsareproducedsothatfuturediseaseencountersareeasilydealtwith.

b. Ifantibioticsareprescribedwhenyouhaveaninfection,bacteriagrowthisinhibited.

c. Antisepticsusedduringoperationsdestroymostdisease-causingagentsthathavegoneintoawoundorincision.

7. Role-playinganimmuneresponseisanexcellentwaytohaveparticipantsperformself-assessment.Teachersmaywanttodeveloporuseaperformance/presentationrubricorhavestudentshandintheirscriptsforreview.


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science 30 unit a ch 1 suggested answers...like a chambered furnace for the body. there were lots of...

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