2021 TYS Answers (ThatBioTutor)

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) TYSAnswers2021(ThatBioTutorEdition) IMPTNOTE:- fordifferencesbetween2023and2024syllabus,seethislisthere.- *Shadedblack=outofsyllabusfrom2024onwards Question Ans Question Ans1 C 21 A2 B 22 A3 D 23 D4 D 24 D5 A 25 D6 D 26 C7* C 27 B8 A 28 C9 D 29 C10 A 30 C11 B 31 B12 A 32 C13 B 33 C14* B 34 B15 A 35 A16 D 36 C17 C 37 D18 A 38 B19 C 39 A20 D 40 D *Q7:“Breaksdownoldredbloodcells”isnowafunctionoftheliverthatisoutofsyllabus.*Q14:CarbonicAnhydraseoutofsyllabus,theyarenotproducedbywhitebloodcells. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q1. (a)● P:Venacava● Q:Rightatrium (b)● Coronaryarteriesbranchfromtheaorta,bringingoxygenatedbloodtotheheartmuscles,● Supplyingthemrichlywithoxygenandnutrientsforaerobicrespirationtocarryoutmuscularcontractionsneededtokeeppumpingblood. (c)● Atthelungs,oxygendiffusesintobloodcapillariesfromalveolarairspaces,● andisbroughtinthebloodtotheheart’sleftatriumviathepulmonaryvein,● thenmovesintotheleftventriclepastthebicuspidvalve.● Itispumpedpasttheaorticsemi-lunarvalveintotheaorta,thentravelstothekidneysviatherenalarteries. (d)● Whenbloodvesselsaredamaged,damagedtissuesandplateletsreleasethrombokinase,whichconvertsprothrombintothrombininthepresenceofcalciumions.● Thrombinconvertsfibrinogentofibrin,forminginsolublefibrinthreadsthattrapredbloodcells,formingaclotatthesiteofinjury.● Whenbloodvesselsaredamaged,plateletsareactivated,whichtriggertheconversionofsolublefibrinogenintoinsolublefibrin,● ForminglonginsolubleFibrinthreadswhichtrapredbloodcells,formingaclotatthesiteofinjury. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q2. (a)*Note:Questionbackgroundinfosaidthatthewidthofarrowsrepresentamountofenergy.25aufordeathandexcretion=10smallsquares.1smallsquare=2.5au (i) ● 6x2.5au=15au (ii)● Heat (iii)● 20x2.5au=50au.OR:● 90au-15au-25au=50au. (b)● 15au/90aux100%=16.7%(3s.f.) (c) ● Alotofenergy,50/90au=55.6%islostasheat.Byrestrictingmovement,animalsengageinlessmuscularcontractions,● Loweringthedemandforaerobicrespiration,solessenergyislostasheat.● Morethan16.7%ofenergywouldnowbeavailableforgrowth,theanimalswillgrowtofullsizefaster,increasingproductivityofthefarm. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q3. (a)● B:Salivaryamylase● C:Pancreaticlipase/Pancreaticamylase/ProteaseTrypsin/Sucrase/Maltase/Peptidase/Lactase/IntestinalLipase/● A:ProteasePepsin (b) ● Variousmoleculesinfoodarethespecificsubstrates,whicharecomplementarytotheirrespectivedigestiveenzymes,andbindtotheiractivesites.● Theenzymescatalysethereactions,afterwhich,theproductsarenolongercomplementarytotheactivesite,hencetheyleave,● Andtheenzymesremainschemicallyunchangedandcanacceptnewsubstrates. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q4. (a) (b)● 1in4chance/25%. (c)● Intheplacenta,anyexcessphenylalanineinthefoetus’blooddiffusesintothemother’sbloodvessels,andislaterbrokendownbythemother.● Henceduringpregnancy,thefoetus’bloodwillnothaveabuild-upofphenylalanine,hencewillnotshowsymptomsPKU. (d) ● DownSyndrome. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q5.(a)● Theprocesswherebytoxicsubstancesandmetabolicwasteproductsareremovedfromthebody,● Preventingitfromaccumulatingtotoxiclevelsandinterferingwithmetabolicreactions.● Theymustbeexcretedastheycanharmthebodyiftheyareallowedtoaccumulatetohighconcentrations. (b)(i)(ii) (c)● Visthecollectingduct.MoreADHinthebloodincreasesthepermeabilityofthecellsofthewallofVtowater.● Thisincreasestheamountofwaterreabsorbedfromthefiltratebackintothebloodstream,increasingurineconcentration. (d)(i) ● Bothdialysisfluidandbloodplasmacontainusefulsubstancessuchasglucose,mineralsaltsandaminoacids.● Bloodplasmacontainsbloodproteinssuchasprothrombinandfibrinogen,whilethedialysisfluiddoesnot. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:)● Bloodplasmacontainsmetabolicwasteproductssuchasurea,whilethedialysisfluiddoesnot. (ii)● Asthedialysisfluidhaszerowasteproducts,aconcentrationgradientexistsbetweenbloodanddialysisfluid.● Asbloodpassesthroughthedialysismachine,wasteproductssuchasureadiffuseoutfrombloodtothedialysisfluid,sothatcleanedbloodisreturnedtothepatient. Q6. ● ArestrictionenzymeisusedtocutasectionofDNAcontainingthehumaninsulingene,creatingstickyends.● Thesamerestrictionenzymeisusedtocutaplasmid,creatingstickyends.● Plasmidandtargetgenearemixed,allowingthemtoannealviacomplementarybasepairingatthestickyends.● DNALigaseisaddedtosealthemtogether,resultinginarecombinantplasmid.● Mixthiswithbacteria,andheatshock/electricshocktreatmentisapplied,creatingporesinthebacteria’splasmamembranetoallowtherecombinantplasmidtoenter.● Thetransgenicbacteriawillthenproduceinsulinaspartoftheirmetabolicprocesses. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q7.(a)(i) (ii)● 0.31moldm -3 (iii)● +0.5% (b) ● Astheconcentrationofsucrosesolutionpotatostripsareplacedinincreasefrom0.0to1.0moldm -3 ,percentagechangeinlengthdecreasesfrom+7.0%to-6.0%.● Whenplacedinsolutionswithhigherwaterpotentialthanthatofthepotatocells,watermovesinbyosmosisdowntheconcentrationgradient,makingthecellsexpandandmoreturgid,increasingsizeofthestrip.● Whenplacedinsolutionswithlowerwaterpotentialthanthatofthepotatocells,waterexitscellsbyosmosis,thecellsbecomeflaccid,hencethestripshrinks. Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) (c)Draw:Blue(centralvacuole)ORRed(plasmamembrane) Stillwantmore?www.thatbiotutor.com- www.instagram.com/thatbiotutor/-www.youtube.com/@thatbiotutor- www.tiktok.com/@thatbiotutor

Credit:WrittenbythecollectiveeffortofourtutorsatThatBioTutor. Youarewelcometosharethesewithanyoneyou’dlike!Justdon’tsellthemforprofit:) Q8. (a) Structure1:HairExplanation:Hairsstandupduetocontractionofhairerectormuscles,trappingalayerofair,whichisapoorconductorofheat,reducingheatlosstothesurrounding. Structure2:Thermoreceptor/NerveendingExplanation:Detectsthecoldskintemperature,generatingnerveimpulseswhicharesentalongthesensoryneurone. Structure3:SensoryneuroneExplanation:Carriesnerveimpulseswhichwilltraveltowardsthehypothalamus,whichwilltriggercorrectivemechanismstoraisebodytemperature. Structure4:Fatty/AdiposetissueExplanation:Fatsareapoorconductorofheat,reducingheatlosstotheenvironment. Structure5:BloodcapillariesExplanation:Lessb