AES 2019 Bio Prelim ANS

1 ASSUMPTION ENGLISH SCHOOL Sec 4 Biology 6093 Marking Scheme Preliminary Examination 2019 Paper 1 (40 m) Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 D C B A B C D C A B Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 B B C D B C A D C A Q21 Q22 Q23 Q24 Q25 Q26 Q27 Q28 Q29 Q30 A C D C B B B C C B Q31 Q32 Q33 Q34 Q35 Q36 Q37 Q38 Q39 Q40 C B C B B B A D C D Paper 2 Section A (50 m) a P – protein/polypeptide Q- glycerol R – fat/lipid S – glucose/monosaccharide every 2 correct – 1 m 2 b i Benedict’s test 1 b ii Add an equal volumeof Benedict’s solution into the sample; Shake the mixture and place the test tube into a boiling water bath for 3 minutes; If glucose is present, a brick-red precipitate will be formed; 3 points – 2 marks, 2 points – 1 mark, 0 to 1 point – no marks 2 2 a phloem 1 b J and K; K is a leaf which takes in radioactive carbon dioxide for photosynthesis; The radioactive sugars formed in leaf K (through photosynthesis) can be translocated / transported up to J; Radioactive sugars cannot move down to the roots M or leaf L as the phloem at X is removed; 4 c All parts/ J, K, L and M; The phosphorus will be present in the roots M as water is absor bed by the root / plant roots absorbed radioactive phosphate ions; The radioactive phosphate ions can be transport up the xylem to the J, K and L as it remains intact; 3 3 a O: phagocyte/white blood cell P: capillary 1 1 andddddddd K;K;K;K;K;K; s a lllllllleaf whi radi C Q37 Q333333888888 B A A A AA A D DDDDD C polypeptptpttptptpttptptptptpttttptptptptptptptptpttptptttptppppppppppppppppppppppppppp idiiiddiddidididdiddiddddididdidiidiiidididdddddddddddddde e eeeeeeeeeeeeeeeeeeeeeeeeeeeee QQQQQQQQQQQQQQQQQQQQQQQQ --------------- glycerererererererererereerrrerrrrrrrrrrrrrrrrololoolololololololooolloloolollllllllllllllll pid SSSSSSSSSSSSSSSSSSS ––––––––––––– glggggggggggggggggggggggggg uccccccccccccccccccccccccosososososososososososososososossoosossooosssoosoososooososssososososooossossossssse/monosacccccccccccchahahahahaharide every y yyyyyyyyyyyyyyyyyyyyyyyy 2 corrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr ecececeeececececeecececececececeeececeeceeceececececececeeceeeeeceeeceeeececccecececececcececececect t t t t –––––––––––––––––––––– 1 m b i BeBeeeBeeeeeeeeeeBeeeeBeBeeeBeeBeBeeeBBeeeBBeBeeeneneeeeeeeeeeeeeeeeedidididididididididididididictc ’ s tetetetetetetetetetettetetetettetetetttttettettetttttttttttttttt ssssstsssssssssssssssssssssssssssssssssssss b iiiiiiiiiiiiiiiiiiiiiiiiiiii AdAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA d annnnnnnnnnnnnnnnnn eqeqeqeqeqeqeqeqeqeqeqeqeqequauaaaaaaaaaaaaaaaaaaaaaaaaaaaaaall volumemememememememememeemmememmmemmmemmmmmmmmmmeee ofoffoffofofofofoffofffoffofofffoofoofofofofffofoooofofofofofofofofooofofofofooofofofoooffffffo BBBBBBBBBBBBBBBBBBBBBBBBBBBBBeneneeneneneneneneneneneeneneneneneenenenenneneenneenenneneenneeeenenenneneeennnenee edededededededeeededdededdeededeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee icicccccccccccccccct’t’t’t’t’t’t’t’t’t’ttt’tt’t’ttttt’tttt’t’’’’s s sssssssssssssss ssssssssssssssssssssssssssssssss sssossssssssssss lutionononononon iiiiiintntntntntnto ooooo ttht e sa ShSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS ake ththththththththththhthththththhheeeeeeeeeeeeee mimmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm xtxtxxxtxtxtxxxxtxxxxtxxxtxxtxxxxxxxtxxxxtxxtxttttttxtxture annddddddddddddddddddd plpllllllplllplplplplplplplplplppplplplpplplpplppplppplplppp aaaaacaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa e e ee eeeeeeeeeeeeeeeeee eeeeeeeeeeeee thththtththththththththtththththththththhththththhthththththtthththhhhhthtthhttthtttthhhheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeee teteteteeteeeeteeeteteeeteteeeeeeeeeeeeeestssssssssssssssssssssssssssssssssss ttttttubububububube ee e ee inininininintto a bo mimimmmimmimmimimimimimimimmmmmmimimmmmmmimmmmmmmimmmmmimmmmmmmmmmmmimimm nunununununuuuununuuuuunuuuuuuuuuuuuunuuuuuuuuuuuutetetetetettettetetetettetetetetttetetetetetttteteteteteeteeeeeeeeeeees;s If gluucocococococococococococccccocccocccococccococococcccccccocooooooosesssssssssssss is s ssssss sssss sssss ss ssssss prprpppprpprprpprpprprppppprprpprpprpprprprprprprprprprppprrprrprrprprprrrrprrpppppp esesesesesesesesesesesesessesesssesessessssssssssenenenennenennennnneneneneeeeeeee t,t,t,t,t,t,t,t,t,t,t,t,t,t,t,t,t,t,t, aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa brbbbbbbbbbbbbbb ick - rererererered ddddd prppppp ecipit 33333333333333333333333333 popopopopopopppopoppopopppppp inininninininnnnininnnininnninnnininnnnnnnntstststststststststststststststtstststtstststtsttsttssssssssssssssss –– 2 2 2222 222222222 2222222222222222222222 mamamamamamamamamamamaamaammamamaamaamamammmammmmmmmmmmmmmmmmmmmmmmmmmm rks, 22222 ppppppoioioioioiointntntntntnts – 1 phlololololooololooloooolooooooooooooooooooooooememeeeeeeeeeeeeeee www.KiasuExamPaper.com 39

2 b M: the lymphocyte produces antibodies that causes the bacteria to clump together; N: The bacteria is being engulfed and ingested by phagocytes /phagocytosis of bacteria; 1 1 c The platelets are activated; Causing soluble fibrinogen to be converted into insoluble fibrin; The fibrin forms a mesh; to trap red blood cells; to form a clot; 5 points – 2 marks, 3 to 4 points – 1 mark; 2 d i lower for both 1 d ii Glucose and oxygen diffused through the capillary into the skin cells; for the cells to perform aerobic respiration; 1 1 4 a i pancreatic trypsin/amylase/lipase 1 a ii small intestines / duodenum 1 b i insulin 1 b ii Insulin helps to decrease blood glucose concentration when it increases after absorption of glucose after a meal; Insulin helps to decrease blood glucose concentration by x increasing permeability of cell membrane to glucose, increasing rate of glucose uptake; x stimulating the liver to convert glucose into glycogen for storage; x increasing oxidation of glucose during tissue respiration; (any 2 of 3 points) 1 2 5 a Continuous Variation Discontinuous variation height weight blood type 1 bA m y and Christie. They are the only ones with identical blood groups; 1 c Couple 1.; They are the only ones with possibility of having allele IO. IO is a recessive allele and must be present in both the paternal and maternal genes in order for Amy and Christie to have blood group O. 1 1 1 d 100% 1 6 a insect: P, S, T wind: Q, R 5 correct – 2 marks, 3 or 4 correct – 1 mark 2 b The stigma is feathery; to provide a larger surface area; to capture more; pollen grains; ever y 2 correct – 1 mark 2 c i line + label L on sti gma of P or R 1 c ii After pollination; the pollen grain germinates; The pollen tube grows as it secretes enzymes to digest; the tissue of the stigma/style; Every 2 points – 1 mark 2 concentrarararararatitititititionononononon wwwwwwhehehehehehennnnnn iti increas d glucose concncncnccccceeeeeneneneneenenenennenenenenenenenenennenenenenennntttrtrtrtrtrttrtrttrttrtrtrtrtrtttrtrtrttttttttttttttttttttttttrtttrtrrrrtttrtrrttttrttttrttrtrttttttttrttttrrtrtrraaatatatatatatatatatatatatatatatatatatatatatatatatatatiooooooiioioiooiioioioooioiooioiooiooioioooioioiooioiiooooiooooooiooooonnnnnnnnn by ability offffff ccccccceeeeeleeeeeeeeeeeee l memememememeeeemeeemeeeeeeeeeeemmmmbmbmbmmbmbmbmbmbmbmbmbmbmbmbmbmbmbmbmbmbmbmbmmmmmbmmbmbbmbbmmbmmbbmmmmmmmmmmmmmmmmmmmmmmmmmm rararrarrrararararararararrarrrrarararararararararararararararaanenenennnnnnennnnenenenenenenenenenennnenenenenenenenneneneeneeeeeeeeeeeeee ttttttttttttttttttttttttttttttttooooooooooooooooo o ooooooooooooooooooooooooooooooooooooooooooooooooooooooo glglglgggggg ucosssssse,e,e,e,e,e, iiiiiincncnnnn reasing rat ke; ng th eeeeeeeeeeeeeeeeeeee liliiilililllllliiillillilillililivevevvvvvvvvvvevevvvvevevevevevevevvvevvevvevvevevvevevvvveer tototototototototototttotttttt ccccccccccccconveertrtrtrtrtrtrtrtrtrtrtrrtrt gggggggggggggggggggggggggggglucosesesesssseeeeeesssesseeeeseeesseeeeseeeseeeeeeeeee iiiiiiiiiiiiiiinto glglglglglglycycycycycycogenenennnn fffffforororororor storagegegegegegee;;;;;; easing oooooooo