Sec 4 Science Biology SA2 2018 Regent QP

10 21 The figure shows the female reproductive system. Which is correct? EF G H A cell organ tissue organ system B cell tissue organ organ system C tissue cell organ organ system D organ system tissue organ cell 22 Which of these processes require energy? diffusion osmosis A + + B - - C + - D - + 23 Which matches the large molecule to its basic units? basic unit large molecule A amino acids fat B glucose glycogen C glycerol glycogen D starch glucose E FG H key: + energy required - energy not required 2018 Sec 4 Science Biology Sa2 - Regent www.KiasuExamPaper.com 268

11 24 The figure illustrates the ‘lock and key’ hypothesis of enzyme action. Which are the substrate, the enzyme and the active site? substrate enzyme active site A X Y Z B X Z Y C Y X Z D Z X Y 25 The table shows the amount of certain substances in different blood vessels. oxygen carbon dioxide digested nutrients A +++ + + B + +++ + C +++ +++ +++ D + + +++ key: + low amounts ++ moderate amounts +++ high amounts Which best represents the hepatic portal vein? X Z Y www.KiasuExamPaper.com 269

12 26 Which describes the function of chlorophyll during photosynthesis? A absorb carbon dioxide B absorb oxygen C trap light energy for production of starch D trap light energy for conversion of light energy into chemical energy 27 Which conditions will cause a plant to transpire the most? temperature /qC humidity /% light intensity /arbitrary units A 15 30 16 B 25 30 16 C 37 20 14 D 37 60 14 28 The table shows the full blood count of a child suffering from Thalassemia, a type of blood disorder. Thalassemia Normal range number of red blood cell per litre of blood 2.77 x 1012 3.9 – 5.3 x 1012 number of white blood cell per litre of blood 8.4 x 109 5.0 – 17.0 x 109 number of platelet per lire of blood 192 x 10 9 150 - 450 x 109 amount of haemoglobin / g/dl 7.5 11.5 – 13.5 Which statement describes the effect Thalassemia may have on th e child’s health? A He is often pale and breathless. B His blood does not clot. C He is unable to fight against bacterial infections. D His red blood cells are not able to carry oxygen. www.KiasuExamPaper.com 270

13 29 The figure shows the double circulation of blood. Which of the following statements is correct? A Blood vessel 1 carries blood under high pressure. B Blood vessel 2 is an artery. C Blood vessel 3 carries oxygenated blood. D Blood vessel 4 have thick and muscular walls. 30 The figure shows the effect of vigorous exercise on blood pH. Which statement explains the change in blood pH? A There is an increase in oxygen levels in the blood. B There is an increase in carbon dioxide levels in the blood. C The muscles are undergoing anaerobic respiration. D The muscles are suffering from aches and fatigue. 1 2 3 4 blood pH time /min www.KiasuExamPaper.com 271

14 31 In the nervous system, which of the following are NOT considered effectors? I photoreceptors II salivary glands III sensory cells in the skin IV sphincter muscles of the alimentary tract A I and III B II and III C II and IV D III and IV 32 The figure shows the blood glucose concentration of two individuals, P and Q. Based on the figure, which hormone is responsible for regulating the blood glucose concentration for individual P and how much is it found in the blood? hormone involved hormone levels in blood A glucagon high B glucagon low C insulin high D insulin low P Q www.KiasuExamPaper.com 272

15 33 Which of the following correctly describes the relationship bet ween genes, DNA and chromosomes? A A gene is a short segment of DNA. B Base pairing of chromosomes results in the double helix structure. C DNA is made up of many chromosomes joined together. D The condensed form of genes is DNA. 34 What causes sickle cell anaemia? A a change in chromosome number B a change in the structure of a gene C a virus infection D uncontrolled cell division of red blood cells 35 The figure shows a leaf with buds growing from it. Which row describes the type of reproduction and the genotype of the offspring? reproduction genotype A asexual genetically dissimilar B asexual genetically identical C sexual genetically dissimilar D sexual genetically identical buds www.KiasuExamPaper.com 273

16 36 The figure shows the cross section of a flower. Where does pollination and fertilisation take place? pollination fertilisation A 1 2 B 2 1 C 1 4 D 2 4 37 The figure shows the fertilisation of the human ovum and subseq uent development. Which statement is correct? A Y is an ovum released by the ovary. B Z is the zygote. C Y is implanted into the uterine lining. D Z is implanted into the uterine lining. 1 2 3 4 Y Z www.KiasuExamPaper.com 274

17 38 The figure shows the number of people in country X infected with HIV from 2012 to 2016. What conclusion may be drawn from the figure? A The number of women infected decreases every year. B More men died from AIDS than women. C The decrease in number of men and women infected by HIV could be due to effective programmes that educate the public on HIV infections. D The increase in tax on condoms resulted in the rise of HIV infections. 39 The table shows the amount of energy available when man feeds o n a producer and a primary consumer. producer primary consumer amount of energy available /KJ 1 000 100 Based on your knowledge on energy transfer, which statement bes t explains the table? A Less energy is available in producers as not all light energy from the sun can be absorbed. B Less energy is available in the primary consumer as it stored m ost of the energy as carbohydrates. C More energy is available to man if they feed on producers as mo st of the energy is lost as it is transferred from one trophic level to another. D More energy is available in producers as they exist in greater numbers. www.KiasuExamPaper.com 275

18 40 The figure shows the amount of submerged aquatic plants present and the bacterial count in four different rivers. In which river has eutrophication occurred? - End of Paper - www.KiasuExamPaper.com 276

2 Section A [45 marks] Answer all the questions in the spaces provided. 1( a) Fig. 1.1 shows an animal cell. Fig. 1.1 (a) Name the following labelled organelles as shown in Fig. 1.1. [2] (i) G ……………………..…………. (ii) H ………………………………… (b) State the function of the organelles labelled [2] (i) F …………………………………………………………………………….. ……………………………………………………………………………….. (ii) G …………………………………………………………………………….. ……………………………………………………………………………….. www.KiasuExamPaper.com 277