Dunman 2024 6093 prelims_P1+P2 MS

Page 1 of 8 DUNMAN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 - SECONDARY 4 EXPRESS BIOLOGY 6093 (MARKING SCHEME) Paper 1 1 2 3 4 5 6 7 8 9 10 D B C B A A B C A B 11 12 13 14 15 16 17 18 19 20 B A C A B D C D A C 21 22 23 24 25 26 27 28 29 30 D B A D C C B A B B 31 32 33 34 35 36 37 38 39 40 D C A D B C A C C B Paper 2 Question Marking scheme 1 (a) A : rough endoplasmic reticulum / (Reject rER) [1] function: Transports proteins made by the ribosomes to the Golgi body / Site of protein synthesis [1] (b) water potential of cell increases [1] and becomes higher than the water potential in the lumen of the small intestine [1] with the secretion of ion X water moves out of the cell down a water potential gradient [1] across the partially permeable membrane by osmosis [1] (c) (i) The vaccine contains antigens / part of the pathogen/ weakened form of the pathogen/cholera bacteria [1] The vaccine stimulates the white blood cells to produce antibodies quickly to destroy the pathogen before they infect the body cells. [1] (ii) - wash hands with soap and water before handling food [1] - drink boiled water/ bottled drinking water [1]

Page 2 of 8 Accept any logical answers 2 (a) (i) D: retina [1] E: fovea / yellow spot [1] (ii) Any 3: transport glucose / amino acids / minerals / vitamins for growth and repair of cells [1] transport oxygen and glucose for (aerobic) respiration [1] transport urea / carbon dioxide away from cells by diffusion [1] capillaries transports blood with white blood cells to fight infection [1] (b) (i) Accept either time [1] (ii) Ciliary muscles contract, relaxing their pull on the suspensory ligaments [1] Suspensory ligaments slacken, relaxing their pull on the elastic lens [1] (c) Box 1: sensory / afferent neurone Box 2: motor / efferent neurone /fibre Box 3: effector / muscle / gland / A named effector 3 correct = 2 marks 1 or 2 correct = 1 mark 3 (a) Dominant allele is one of the different forms of a gene that expresses itself and gives the same phenotype in both the homozygous and heterozygous condition. [1] F F

Page 3 of 8 (b) (i) father x mother genotypes of parents …………Hh…………… …………hh…………… gametes ….H…. ….h…. ….h…. ….h…. genotypes of offspring … Hh …. … Hh …. … hh …. … hh …. [1] for each correct row of answers (ii) 2/4 x 100% = 50% [1] (c) (i) HH, Hh [1] (ii) 1 and 2 with HD having child 5 without HD [1] (d) Ribosome cannot attach and move along the mRNA that is bound to the drug [1] OR bound mRNA cannot be used to synthesise proteins [1] by ribosomes [1] Less mRNA to synthesise polypeptide of huntingtin protein [1] Less huntingtin protein to cause damage to nerve cells [1] 4 (a) (i) Photosynthesis (ii) it stops the process/photosynthesis and no oxygen is produced [1] algal balls are more dense [1] (b) (i) With light, shar