CCHY 2014 Bio Yearly TYS ANS

6093 Biology Yearly TYS 2014 No Paper 1 Marks Remarks 1 A 1 2 B 1 3 C 1 4 C 1 5 D 1 6 B 1 7 B 1 8 B (supposed to be breakdown of haemoglobin; not RBC) 1 9 B 1 10 C 1 11 D 1 12 C 1 13 D 1 14 C 1 15 D 1 16 C 1 17 A 1 18 C 1 19 A 1 20 C 1 21 C 1 22 C 1 23 C 1 24 D 1 25 C 1 26 D 1 27 B 1 28 A 1 29 C 1 30 A 1 31 C 1 32 D 1 33 C 1 34 C 1 35 B 1 36 A 1 37 A 1 38 C 1 39 A 1 40 B 1 Total 40

Paper 2 Section A No Answer Marks Remarks 1a Process by which metabolic waste products and toxic substances are removed from the body of an organism; Metabolism produces waste products + accumulation of waste/excretory products of metabolism can be toxic + harmful to the organism + must be removed immediately; 1 1 1bi 200 – 17 = 183 1 1bii Uric acid/ creatinine/ excess water 1 1c Increase water potential above normal level in blood plasma stimulates hypothalamus in the brain to trigger pituitary gland to release less ADH into bloodstream; ADH stimulates cells in the walls of the collecting ducts to become less permeable to water + less water reabsorbed from the collecting duct into the blood capillaries; Larger volume of urine + urine produced is more diluted / lower concentration; 1 1 1 Total 7 2a Liver 1 2bi Volume of pure alcohol consumed = 3 × 175 × 12 100 = 63 𝑐𝑚2 No of units of alcohol consumed = 63 ÷ 10 = 6.3 units 1 1 2bii Amount of time = 6.3 units ÷ 1h = 6.3h 1 2c Short-term: Reduced self-control + effect; increased reaction time/ slow reaction + effect; blurred vision + effect; poor muscular co-ordination + effect; unable to walk steadily + effect; slurred speech + effect; judgement deteriorates + effect; long-term: liver cirrhosis + elaboration; stomach/gastric ulcers + elaboration; addiction/ alcoholic + elaboration; 2 2 TB pg. 107-108 Total 8

3ai Vein/ branch vein 1 3aii Xylem tissue; Forms a continuous lumen/hollow tube without any partition walls/ protoplasm + Transports water and dissolved mineral salts to mesophyll cells from the roots; / Phloem tissue; Sieve tube cells are joined end to end to form sieve plates + Conducts manufactured food (sucrose and amino acids) away from the leaf to the other parts of the plant; 1 1 Identify Structure + Function 3bi Transpiration 1 3bii 17 – 8 = 9 h 1 3biii 6th hour + 20th hour 1 3biv Humidity of air/ Wind or air movement/ Light intensity 1 Total 7 4a A carbon sink is an area that stores carbon compounds for an indefinite period + stores more carbon than it releases; removes carbon dioxide from atmosphere, reducing the rate of global warming; 1 1 4bi Aerobic respiration 1 4bii Changing land use and agriculture takes in more carbon dioxide than releases carbon dioxide by 1 gigaton of carbon a year 1 4biii Sum (Release – absorbed) = (119 – 120)