9700_w02_ms_2

9700_w02_ms_2 - CAMBRIDGE INTERNATIONAL EXAMINATIONS...

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Unformatted text preview: CAMBRIDGE INTERNATIONAL EXAMINATIONS NOVEMBER 2002 Iary Level GCE Advanced Subs UNIVERSITY of CAMBRIDGE Local Examinations Syndicate «Mark Scheme ' - I Syllabus _ ' As Level Examinations—November 2002 9700 n Question Expected Answers - V ‘ M Marks 1 (a) correct measurement of scale bar used as basis for finding A magnification With apprOpriate working; ’ A. 1.7 - 1.9 cm for length" of scale bar e.g. xxmmx l 000 .. 10 = Xm; A. any fig. betweenx 1700- 1900 '- 2 NB. award one mark if correct answer given without any ' . working shown (b) movement of air / oxygen into alveoli; concentration gradient (between alveolar air and blood) / AW (for either oxygen or carbon dioxide); '" oxygen dissolves in film of liquid / surfactant fluid; diffusion; "-‘ oXygen and carbon dioxide exchanged (idea of); squamous / alveolar / pavement epithelium; } A. alveolar/capillary endothelium (of capillary); } wall gage red blood cell; ref to short diffiision distance into capillary / one cell thick / 2-3 pm; ’ R. thin wall ' ' ‘ 4 max (c) _B_ lymphocyte / B cell / plasma gefl; I 1 (d) secretion of mucus by, goblet cells / glands; ” ‘ flgi_d leaks fr0m capillaries; R. capillaries permeable contraction of (smooth) muscle / muscle spasm; congestion / blocking / narrowing / AW, of airways / bronchioles; ' ’ 1.. increased resistance to air flow / air flow restricted; 3 max ‘ [T otal: 10] Mark Scheme '- - Syllabus _ AS Level Examinations — November 2002 9700 n Question Expected Answers V Marks 2 (a) (i) A glycerol; B fatty acid; - V 2 (ii) condensation / esterification/ ester bond formation; 1 -' (b) more energy released / stored per gram / unit / given mass; R. per mole 37 k1 v 17 U; A. (37—40 1d) v (15-17 M) A.'ei1uivalent - ' 4 calorific values if calculated ‘ fats are highly reduced; V more hydrogens / fewer oxygens / higher carbon to hydrogen ratio / more CH bonds; release / yield more energy when respired / oxidised; 2 max (1:) 20%. or more above the recommended weight / mass for height ‘/ BMI / Body Mass Index / mass kg greater than 30; . (height in In)2 A. within range (30-40) 1 ((1) diabetes; _ coron_ary heart disease / atherosclerosis / cardiovascular disease / stroke / AW; ' ' hypertension / high blood pressure; cancer; arthritis / joint problems; hernia; varicose veins; gallstones; increased risk during surgical operations; 2 max [Total : 8] ~- ‘Mark Scheme ‘ I AS Level Examinations - November 2002 Syllabus , — :- Question ' Expected Answers I: ‘ Marks 3 (a) stomata (are open) for gas exchange / C02 / 02 uptake / release a . (for photosynthesis and respiration); large surface area / many cell surfaces; a in spongy mesophyll; (so) evaporation fiom (damp) walls (into air‘spaces); (and) difl'hsion / loss down a cone. gradient, of Water vapgur; to air / atmosphere via stomata; V V 3 max (b) ref‘cohesion /_tension in context of xylem); hydrogen bonds; ' ' . . through (freely permeable) cell wall / apoplast pathway; through partially permeable membrane / AW (in context of cell B); osmosis; - :- down water potential gradient / high / less negative to low / mere negative water potential / AW; 3 max (c) (i) B to A and C; A to C; 2 (ii) from cell surfaces through air through stomata; 1 ((1) small leaves / small surface areal reduction of leaf surfaces / needle shaped leaves; R. spines - rolled / curled leaves; R. folded shed leaves; sunken stomata / stomata in pits / crypts / grooves; stomata surrounded by hairs / hairy leaves; waxy/ impermeable / thick, cuticle / thick leaves qualified; 2 max .[Total : ll] — AS Level Examination-s - November 2002 Question 4 (a) (b) (i) (0 (ii) -:‘Mark Scheme ' . v Syllabus ‘- Expected Answers Marks active site; specific shape / configuration / conformation (in ref to active site); complementary to substrate / exact / perfect substrate and active site); combine to form enzyme-substrate / ES complex; ' mould around substrate / substrate alters shape of active site (induced fit); R. induced fit unqualified ref to temporary bonds / named bond; fit (between 3 max EcoRl ; sticky ends; plasmid DNA cut with same restriction enzyme / endonuclease; DNA and plasmid mixed together / AW; 'R. inserted ref complementary / base pairing / C and G on sticky ends pair up; ref to hydrogen bonding; ligase forms bonds between sugar and phosphate / phosphodiester bonds; 3 max _ [Total : 8]~ Question} 5 (a) (b) (6) Question 6 (a) » . '1 Mark Scheme ' - - Syllabus _ AS Level Examinations — November 2002 9700 n 1 Expected Answers Marks I female, Anopheles, mosquito sucks blood fi'om (infected) person; R. bites ‘ parasites / plasmodia / pathogens reproduce / multiply / form gametes (in mosquito); - injects / inserts / pumps in / (saliva) with parasites / transmits / transfers parasite as feeds / in saliva (into uninfected person);- 2 max _ malarial parasite has» nucleus / nuclear membrane / nuclear envelope; mitochondria; , membranous organelles; R. ribosomes R. nucleolus V 2 max fewer red blood cells / number of r.b.cs. reduced; due to burstng / rupturing of r.b.c. / parasite destroys r.b.cs.; less haemoglobin; less oxygen transported / reduced ability to carry oxygen; waste excreted / toxins released (by parasite); symptom; A. o_ne_ from - anaemia/ fatigue / tiredness / muscular pain / headaches / nausea / fever / high temp. and sweating / inability to control temp. / shivering 3 max [Total : 7] Expected Answers Marks anaerobic; R. inaerobic, R. unaerobic lactate / lactic acid; . liver; '_ " '5debt; '.R. deficit aerobic; resting; _ U ’ 6 [Total : 6] Total mark for paper = 50 ...
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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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9700_w02_ms_2 - CAMBRIDGE INTERNATIONAL EXAMINATIONS...

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