CCHY 2015 Bio Yearly TYS ANS

6093 Biology Yearly TYS 2015 No Paper 1 Explanation 1 B Cytoplasm present in RBC 2 C Oxygen is used up in mitochondria during aerobic respiration 3 B Against concentration gradient across a membrane 4 B Starch is storage form of glucose in plants 5 B 6 B 7 D 8 B Enzymes are secreted into the small intestine from the pancreas or intestinal glands. Liver only produce bile that is stored in the gall bladder. 9 D 10 A 11 B 12 C Rate of p/s exceeds rate of aerobic r/p 13 C 14 B 15 B 16 B 17 D 18 C 19 C 20 C High hydrostatic pressure 21 B 22 D 23 B 24 A 25 D 26 A Sensory neurone is damaged 27 C 28 B 29 A Male gamete has x and y chromosome 30 D 31 C Gene loci are at the same position 32 B 33 B 34 A 35 A 36 D 37 A 38 A 39 A 40 B Total 40

Paper 2 Section A No Answers Marks Remarks 1a A: starch B: maltose C: salivary amylase 3 1bi Temperature in the alimentary canal 1 1bii pH in the alimentary canal 1 1c Bile cannot be released from the gall bladder into the small intestines; Fats will not be emulsified into smaller fat droplets + surface area to volume ratio is not increased; Slower rate of digestion of fats by lipase; 1 1 1 Total 8 2a Sexual reproduction involves a process of fusion of nuclei of male and female haploid gametes to form a diploid zygote; Produces genetically dissimilar offspring; Gametes are produced by meiosis; 1 1 1 2b Rough surfaces + cling onto hairy body of insects; Insect follows nectar guide into flower to collect nectar + transfer pollen grains from anther of another flower to sticky stigma; 1 1 Structure + function Explain 2ci A is the pollen tube 1 2cii Pollen tube grows down the style into the ovary + pollen tube secretes enzymes to d igest surrounding tissues of the stigma and style; Pollen tube enters the ovule through micropyle + within the ovule, the tip of the pollen tube absorbs sap and bursts + releasing two male gametes; Nucleus of one male gamete fuses with the nucleus of the ovum to form a zygote + nucleus of the other male gamete fuses with the definitive nucleus to form the endosperm nucleus; 1 1 1 Describe + explain Total 9

No Answers Marks Remarks 3a 40 – 16 = 24 1 3b The higher the air temperature, the higher the body temperature of insect; No thermoregulation mechanism in the body 1 1 Relationship 3c Horizontal line from 20°C to 36°C of air temperature – constant human body temperature is 37°C 1 3d Temperature is higher than normal body t emperature detected by thermo-receptors in the skin stimulates sweat glands to become more active; Increased production of sweat by sweat glands + more water in sweat evaporates into water vapour from surface of the skin; More latent heat of vaporisation lost from body + body temperature decreases/restored to normal level 1 1 1