ANS P4 - CAMBRIDGE INTERNATIONAL EXAMINATIUNS JUNE 2002 GCE...

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Unformatted text preview: CAMBRIDGE INTERNATIONAL EXAMINATIUNS JUNE 2002 GCE Advanced Level MARK SCHEME MAXIMUM MARK : 50 SYLLABUSICOMPONENT :9700 I4 BIOLOGY (STRUCTURED QUESTIONS (A2 CORE)) UNIVERSITYafCAMBRIDGE 5'" Local Examinations Syndicate Marksman-e —Pa per _ Mm: Examinations-Juneau .- Question 1 til thylakoid (membrane) f Iarneliae : in grana ; . - 2 lb) source of energy ; to excite electrons : for synthesis of ATP (from ADP} ; and reduced NADP rNADPHl NADPHzl NADPH‘; ref. photolysis (of water) : 2 max M 1 electron lost from photosystem ll fnon cyclic has PSII and PS! I cyclic has only PSI : 2 replaced by electron from water in noncyolic ; 3 ref. to photolysis ofwater {oxygen produced in noncyciic: 4 non cyclic produces reduced NADP l NADPH l' NADF’H; f NlfltDPH+ ; 5 excited electron retums to chlorophyll .l photosystern 1 in cyclic ; Eelectron not-taken from hydroxyt ion I water. in cyclic: 4 mm; id} idea that paraquat can be used to trill weeds around growing crap ; 1 Totat : 9 Question 2 till ratio of volume r moles f amount of carbon dioxide evolved to volume of oxygen absorbed in respiration ; 1 {hi depends on substrate ; greater than 1 some anaerobic respiration l ref. to a anaerobic respiration : carbohydrate 1 l protein 0.9 ! fat 0.7 ;; 2 out ch? ref. to other metabolic processes using oxygen ." produce carbon dioxide ; 2 max (cl time i allowed to equilibrate: record level of fluid in manometer : change in known time 1 ref. lime : repeat : open clip and reset level ; ref units : ref to boiled seeds as a control : as soda lime absorbs carbon dioxide given off ; ref. to calwlation ; 4 max tdi remove soda lime ; repeat experiment l ref. to comparison ; ref. to whether manometer rose orfell ; ref. to caimlation : 2 max (Bl ref efiecl of temperature on mass in respiration ; ref. named effect of temperature eg increased collisions l kinetic energy l more substrate moledules with activation energy ; ref. to {119 = 2 2 max Total: 11 . Mark Scheme Syllabus — A Level Examinations — June 2002 9700 4 Question 3 {a} chance proteins} ref. gal ; Na' K‘icationpumplcarnerprotein: diffusion down elecbodiernical gradient ; 2 max lb} (0 Na’ in : cause depolarization f figures —6tim‘u' to +4Drn'v' ; ref. action potential : 2 mu (5) K‘ out i restores resting potential {rapolarisation : 2 it) acts as an insulator ; action potential cannot tire in part of axon covered by myelin sheath fonly at node of Ranvier; Na*..f K’. camot pass across jumps from node to node I ref. saltation 1 ref. to local ciruilts: speeds up impulse transmission ; _ 3 max :rdgquency of impulses : _ 1 Total : 10 Question 4 la} (i) formation of glornemlar filtrate f ulbafiflration 1' pressure filtration ; (soluble) molecules I water, urea, glucose in plasma forced into nephroni kidney tubule ; 2 {ii} removing reabsorbed molecules ; water 1 glucose ; 2 (iii) removing water: from f reabsorbed by collecting ducts : ref. to maintain water potential gradient (in medulla} 2 max {bl Enneabiliu can be varied : correct ref. to ADH ; if (blood) water level i' potential is low more water reabsorbed : if (blood) water level i potential too high Iitde i no water reabsorbed : 3 max lc) diet has to be regulated carefully when not on the machine ; risk of infection ; limited mobility Mien on machine it ref. to time on machine : ref. to expense '. difficulty of finding 1reins f damage to veins : AVF’ ; 2 max Total : 11 W Marksman lam— Pa er — A Level Examinations — June 2002 9700 Question 5 (all correct parental genotype ; correct gametes ; conect genotypes of offspring : correct phenotypes of offspring linked to genotypes: 4 Rer x Rer RB Rb rB rb l RB Rb rB rb RFBB RRbb ‘ Rer Round yellow Round green Wrinkled yellow Wrinkled green RRBB RRBb RRbb rrBB rrbb RrBB Rer Rrbh rer {hi wrinkled seeds homozygous l double recessive : round yellow seeds variety of different genotypes i may be heterozygotes ; round yellow seeds some do breed true 1' homozygous dominant: 3 (61 probability of as large a deviation as 9.4? is between 0+9 and £195 : indicating a close fit to the expected resutts .l they do not difier statistically {rem the expected result : 2 Total : 5 ...
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This note was uploaded on 01/25/2012 for the course BIO alevels taught by Professor J.b during the Spring '11 term at Taylor's.

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ANS P4 - CAMBRIDGE INTERNATIONAL EXAMINATIUNS JUNE 2002 GCE...

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