CHS 2016 Bio Prelim ANS

2016 SECONDARY 4 BIOLOGY PRELIMINARY EXAMINATION 3 Mark Scheme 5158/01 (40 marks) 1 A 2 B 3 B 4 B 5 A 6 C 7 C 8 C 9 A 10 C 11 D 12 C 13 A 14 C 15 B 16 C 17 D 18 C 19 B 20 D 21 C 22 C 23 B 24 C 25 A 26 D 27 B 28 A 29 B 30 C 31 D 32 D 33 D 34 A 35 A 36 D 37 C 38 D 39 B 40 A 5158/02 Section A (50 marks) 1 (a) V – stomach [1] W– large intestine / colon / rectum [1] I: intestine unqualified 1 (b) mp 1 breaks up food into small(er) pieces [1] R: molecules mp 2without chemical change [1] A: without enzymes mp 3by teeth / muscles [1] A: mastication / chewing / churning mp 4to mix (with digestive juice) [1] mp 5increases surface area [1] mp 6for enzyme action [1] mp 7speeds up chemical digestion [1] mp 8easier to swallow [1] [max 3] 1 (c) for mp 1positive correlation / as (relative) body mass increases + timein digestive system increases [1] mp 2any two or more figures from the graph (units must be quoted at least once) [1] against mp 3two/one/few/some + are outliers/anomalies (e.g. either outlier quoted) [1] mp 4any figure(s) from the graph [1] mp 5(description of) some mammals do not fit the + pattern/trend [1] mp 6 any example from the graph [1] 118 trendylineinstns 33two/one/few/two/one/fewsomesome+ are outliers/anomalies + are outliers/anomalie((e.g. either oute.g. either out 4any figure(s) from the graph [1]ny figure(s) from the graph [1] 5(description of) some mammals d(description of) some mammals do not fit the + pattern/trenot fit the + pattern/tr 6any example fromthe graph [1]1]

mp 7 only information about 26 species of mammal / small sample size [1] mp 8idea about unknown validity [1] mp 3-8 [max 3] mp 1-2 + mp 3-8 [max 4] 2 (a) function letter on Figure 1.1 name structure that separates oxygenated and deoxygenated blood F septum [1] structure that prevents backflow of blood from ventricle to atrium D bicuspid/mitral/atrioventricular + valve A: “AV valve” R: right atrioventricular valve [1] blood vessel that carries deoxygenated blood B H pulmonary artery vena cava [1] chamber of the heart that contains deoxygenated blood J G right atrium right ventricle [1] . 2 (b) (i) mp 1 pulse rate increases and remains constant [1] mp 2immediate/sudden/steep/rapid/AW + increase in pulse rate [1] R: exponential mp 3increases from 44–48 bpm to 164–170 bpm / increases by 120–126 bpm/ by 3.5 to 4 timesor approx 4 [1] mp 4maximum / 164–170 bpm + at 4 min(utes) / 2 min(utes) after race starts [1] R: no units used [max 3] 2 (b) (ii) mp 1 adrenaline stimulates incr ease in + heart/pulse rate [1] mp 2increase in blood + carbon dioxide (concentration) / acidity + detected [1] A: decrease in pH mp 3nerves stimulate heart to beat faster [1] mp 4ref to muscle contraction / AW [1] mp 5muscles require more energy / muscles are doing more work [1] mp 6(rate of aerobic) respiration increases [1] R: ‘produce’ energy mp 7increase demand for + oxygen / glucose [1] mp 8ref to removal of + carbon dioxide / lactic acid / heat [1] mp 9more + blood / carbon dioxide + to lungs (per unit time) [1] mp 10more + blood / oxygen / glucose + to muscles [1] mp 11AVP (e.g. ref to ATP / vasodilation in muscles) [1] [max 4] 3 (a) gene – a length of DNA that codes for a protein [1] R: chromosome / molecule of / genome gene mutation – a change in base sequence of DNA [1] 3 (b) (i) 1 – Bb [1] 2– bb [1] 3– Bb [1] 3 (b) (ii) phenotype of parents: unaffected (by acatalas ia) x affected (by acatalasia) [1] 119 trendylineBb [1]Bb [1] bb [1]b [1] Bb [1]Bb [1]

A: normal/carrier (in place of “unaffected”) R: father/mother/male/female/sick genotype of parents: Bb x bb [1] gametes: B, b, b, b [1] R: lines are not drawn / not correctly aligned genotype ofoffspring: Bb, Bb, bb, bb [1] phenotype ofoffspring: unaffected, unaffected, affected, affected [1] R: “F1/F2 generation” [max 4] 3 (b) (iii) test (cross) [1] 4 (a) carbon dioxide [1] urea [1] 4 (b) 0 / 0.0 (g dm–3) [1] proteins too big, to pass through the capillary wall (in glomerulus) / to be filtered (from theblood) / out of the glomerulus [1] 4 (c) mp 1 blood flows into the (dialysis) machine / blood is returned to the patient [1] mp 2 blood passes over a dialysis membrane / countercurrent flow described [1] mp 3 the dialysis membrane separates the person’s blood and the dialysis fluid [1] mp 4 dialysis fluid contains + glucose / salts / no urea [1] mp 5 movement (across membrane) by diffusi on / down a concentration gradient [1] mp 6 urea leaves the blood / enters the dialysis fluid [1] mp 7 dialysis fluid is refreshed [1] mp 8 excess/some salt + leaves the blood / enters the dialysis fluid [1] mp 9 excess/some water + leaves the blood / enters the dialysis fluid [1] mp 10 glucose/salts in dialysis fluid same concentration as (should be) in blood [1] mp 11 no net loss of glucose [1] [max 5] 4 (d) advantage no need to visit hospital [1] no need for dialysis / time not taken up with dialysis [1] no need for a restricted diet [1] no long term discomfort / pain [1] improved quality of life / lead a normal life [1] [max 1] disadvantage rejection of kidney [1] difficult to find suitable donor [1] risk associated with operation [1] need to take immunosuppressant drugs [1] [max 1] 5 (a) DNA in nucleus (human) / withinnuclear membrane [1] in cytoplasm (bacteria) [1] 120 trendylinex 1]x 1 AA ucleus (human) / withincleus (human) / withinnuclear membrane uclear membrane[1][1 ytoplasm (bacteria)[1]

presence of plasmid(s) (bacteria) [1] correct reference tochromosomes / AW (human) [1] genes / chromosomes paired(human) [1] [max 3] 5 (b) (cell) wall [1] (cell) membrane [1] 5 (c) type: asexual / binary fission / mitosis [1] explanation: genetically + identical (cellsproduced) OR clones [1] all capable of producinginsulin / same product [1] A:to produce insulin in large quantities / to produce a large number ofbacteria / produce bacteria quickly 5 (d) diabetes [1] Section B (30 marks) 6 (a) 280 [1] 6 (b) A axes labelled y-axis: (mean) reaction time / ms x-axis: before drinking alcohol and after drinking alcohol /before and after / or key given x-axis labels approximately under each bar Scolumns at least half the grid on y-axis + even scale [1] Pboth plots accurate ± ½ small square [1] Ccolumns not touching + of same width [1] 6 (c) 220–350 + milliseconds [1] 6 (d) cirrhosis (of liver) / (chronic) liver disease [1] cancer of the liver / stomach / mouth (oral) / throat [1] pancreatitis / kidney failure / liver failure [1] stomach ulcers [1] brain damage[1] heart disease / heart failure/ heart attack / stroke / high blood pressure [1] reduced fertility[1] depression / AW[1] addiction / dependence[1] [max 3] 6 (e) violent crime / domestic violence [1] road accidents / drink driving [1] (petty) crime / vandalism [1] family breakdown / divorce / relationship breakdown [1] 121 trendylineent crime / domestic violenceent crime / domestic violence[1][1 d accidents / drink driving [1]accidents / drink driving [ ty) crime / vandalism [1]y) crime / vandalism [1 ily breakdown / divorce / relationship breakdown [1]nship

impaired performance at work / unemployment / difficulty getting a job [1] [max 1] 7 (a) timber/paper + manufacture / AW [1] A: wood unqualified firewood [1] A: fuel clearance for agriculture [1] urbanisation / roads / housing / factories / industry / leisure developments [1] extraction of minerals/ for other natural resources [1] [max 2] 7 (b) 118 545 - 90 883 = 27 662 27 662/ 118 545 × 100 [1] 23 + % [1] 7 (c) planted forest + has one (dominant) species [1] loss of biodiversity [1] qualification of biodiversity loss (e.g. habitats / example / extinction of a species) [1] I: homes / organisms die (plantation)susceptible to pest / disease [1] nutrients removed / soils become infertile [1] A: use of chemicals ref to alien / foreign / invasive / non-indigenous species [1] AVP (e.g. vegetation is removed / lower canopy / all immature) [1] [max 2] 7 (d) mp 1 root