TKGS 2024 S4 Prelim Bio P1 & P2 Answers

Tanjong Katong Girls’ School Secondary 4 Preliminary Examinations 2024 Answer Key Biology 6093/01 1 B 11 B 21 D 31 B 2 D 12 B 22 B 32 D 3 B 13 C 23 B 33 A 4 C 14 A 24 D 34 A 5 B 15 B 25 B 35 B 6 C 16 C 26 B 36 A 7 B 17 B 27 B 37 B 8 C 18 B 28 C 38 D 9 A 19 D 29 B 39 D 10 D 20 C 30 A 40 A Biology 6093/02 Question Answer Marks 1 (a) One-cell thick wall + decrease diffusion distance, increase rate of diffusion of gases; Close proximity to a blood capillary + decrease diffusion distance, increase rate of diffusion of gases; Max 1m (b) Microvilli; 1m (c) Lacteal; 1m (d) Oxygen; Glucose / amino acids / water / vitamins / minerals; 2m 2 (a) B is thicker, more elastic, more muscular than A; (vice versa) 1m (b) Arrows must show the following to get 1m: 1. right atrium to right ventricle 2. right ventricle to pulmonary artery 3. left atrium to left ventricle 4. left ventricle to aorta 1m (c) Tricuspid valve; Closes during ventricular systole + prevent blood from entering right atrium; 2m (d)(i) (60 / 0.8) = 75; 1m

(d)(ii) time / s at rest during exercise atrium ventricle atrium ventricle 0.0 – 0.1 0.1 – 0.2 0.2 – 0.3 0.3 – 0.4 0.4 – 0.5 0.5 – 0.6 0.6 – 0.7 0.7 – 0.8 0.8 – 0.9 0.9 – 1.0 1.0 – 1.1 1.1 – 1.2 Ventricle contraction – 1 or 2 rectangles, as long as lesser than 3 All chambers relaxation – 1 or 2 or 3 rectangles, as long as lesser than 4 Must shade until the end 1m 3 (a)(i) A – glomerulus; B – collecting duct; 2m (a)(ii) Afferent arteriole’s lumen is bigger than efferent arteriole’s; Creates a high hydrostatic/blood pressure in the glomerulus to force small substances out; 2m (b) Maintain a steep concentration gradient between fluid and blood; (must write properly) Allows waste products to diffuse out of blood into fluid; (reject: “if” answers e.g. if the fluid is not changed…) 2m 4 (a) 6CO2 + 6O2 → C6H12O6 + 6O2; (light energy and chlorophyll written on the arrow); 2m (b) Carbon, hydrogen, oxygen; 1m (c) Proteins in water flea is digested into amino acids; Amino acids is used for growth and repair of cells; 2m 5 (a) Rate of transpiration is higher in environment A than B + 9.8 gh-1 vs 4.7 gh-1; Or Rate of transpiration in environment A is higher than B by 5.1 gh-1; Increase in humidity lowers rate of transpiration; Gentler / lower concentration gradient between water vapour of air spaces of leaves and environment; (must write properly) 3m (b) Did not take into account light intensity; 1m

(c) Prevent evaporation of water from the soil; 1m 6 (a) Double helix structure; 2 strands of polynucleotides that are anti-parallel; 2 strands / each base pair held together by hydrogen bonds; Sugar-phosphate backbone of each strand; Each nucleotide consists of sugar, phosphate group and nitrogen- containing base; 4 types of bases adenine, thymine,