ii Contents Must Know iii – viii Chapter 1 Introduction to Biology and Laboratory Rules NOTES 1 Paper 1 2 Paper 2 5 Chapter 2 Cell Biology and Organisation NOTES 7 Paper 1 8 Paper 2 13 Chapter 3 Movement of Substances across the Plasma Membrane NOTES 17 Paper 1 18 Paper 2 25 Reinforcement and Assessment of Science Process Skills for Paper 3 (Pratical Test) 30 Chapter 4 Chemical Compositions in a Cell NOTES 31 Paper 1 32 Paper 2 38 Reinforcement and Assessment of Science Process Skills for Paper 3 (Pratical Test) 42 Chapter 5 Metabolism and Enzymes NOTES 43 Paper 1 44 Paper 2 48 Reinforcement and Assessment of Science Process Skills for Paper 3 (Pratical Test) 53 Chapter 6 Cell Division NOTES 54 Paper 1 55 Paper 2 62 Chapter 7 Cellular Respiration NOTES 66 Paper 1 66 Paper 2 70 Reinforcement and Assessment of Science Process Skills for Paper 3 (Pratical Test) 72 Chapter 8 Respiratory Systems in Humans and Animals NOTES 73 Paper 1 74 Paper 2 79 Chapter 9 Nutrition and the Human Digestive System NOTES 83 Paper 1 84 Paper 2 89 Reinforcement and Assessment of Science Process Skills for Paper 3 (Pratical Test) 93 Chapter 10 Transports in Humans and Animals NOTES 95 Paper 1 96 Paper 2 101 Chapter 11 Immunity in Humans NOTES 104 Paper 1 105 Paper 2 109 Chapter 12 Coordination and Response in Humans NOTES 112 Paper 1 113 Paper 2 119 Chapter 13 Homeostasis and the Human Urinary System NOTES 122 Paper 1 123 Paper 2 127 Chapter 14 Support and Movement in Humans and Animals NOTES 130 Paper 1 131 Paper 2 136 Chapter 15 Sexual Reproduction, Development and Growth in Humans and Animals NOTES 139 Paper 1 140 Paper 2 145 Answers 148 Contents 1202 Biology F4.indd 2 26/05/2022 5:14 PM
MUST KNOW Important Facts Important Facts (Chapter 1 & 2) 1 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 9 & 10) 7 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 4 & 5) 3 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 12) 9 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 7) 5 @ Pan Asia Publications Sdn. Bhd. Important Facts (Chapter 14) 11 @ Pan Asia Publications Sdn. Bhd. Chapter 1 Introduction to Biology and Laboratory Rules Chapter 2 Cell Biology and Organisation Chapter 9 Nutrition and the Human Digestive System Chapter 10 Transports in Human and Animals Chapter 12 Coordination and Response in Humans 1. A balanced diet is the diet that contains all seven classes of food in the right proportions and balanced quantities according to one’s needs so that optimal health can be maintained. 1. Haemophilia is a hereditary disease caused by the lack or absence of clotting factors in the blood. 2. A blood clot is a thrombus. If the thrombus is transported by blood flow, it is called an embolus. 1. Water, carbohydrates, proteins, lipids and nucleic acids make up the components in a cell. 2. There are two types of carbohydrates, which are monosaccharide and polysaccharide. 3. Nucleotides are made up of nitrogenous bases, pentose sugar and phosphate. 1. Anabolism is the process of synthesis of complex molecules from simple molecules. 2. Catabolism is the process of breaking down complex compounds into simple molecules. 1. The three types of skeletons are the hydrostatic skeleton, exoskeleton and endoskeleton. 2. Antagonistic muscles work in the movement of the forearm and leg muscles when we are walking. 3. Earthworms move using the peristalsis movement. 4. Osteoporosis is very common among older women because a low oestrogen level can reduce bone density. 1. The nervous system is divided into the central nervous system and the peripheral nervous system. 2. Acetylcholine, noradrenaline, serotonin and dopamine are types of neurotransmitters. 3. A reflex action is an automatic response that occurs rapidly and without being controlled by the brain. 4. Drug and alcohol abuse affects the normal functions of the nervous system. 1. Aerobic respiration is the breakdown of glucose involving oxygen to produce chemical energy. 2. This occurs in the mitochondrion and cytoplasm. 3. Fermentation is the process of incomplete decomposition of glucose in conditions of limited oxygen supply or without oxygen at all. 4. This occurs in the cytoplasm. 5. Human muscle cells will undergo oxygen debt when it carries out vigorous training. 1. Biology is the study of all processes related to life and living. 2. Safety and rules in the biology laboratory is important to ensure the safety of the student conducting the experiment, the purity of the sample and the cleanliness of the laboratory. 1. Cell is the basic unit of all living organisms. 2. Cell → Tissue → Organ → System → Organism 3. Revise the lessons you’ve learned in Form 1. Chapter 4 Chemical Composition in a Cell Chapter 5 Metabolism and Enzyme Chapter 7 Cellular Respiration Chapter 14 Support and Movement in Humans and Animals Must Know 1202 Biology Form 4.indd 1 24/05/2022 10:38 AM
MUST KNOW Mnemonics & Important Diagrams Mnemonics (Chapter 6) 13 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 1) 19 @ Pan Asia Publications Sdn. Bhd. Mnemonics (Chapter 11) 15 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 2) 21 @ Pan Asia Publications Sdn. Bhd. Mnemonics (Chapter 12) 17 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 4) 23 @ Pan Asia Publications Sdn. Bhd. Biology comes from Greek word Definition – science of life by studying the life processes and of living organisms Bios – means life logos – means knowledge Biology Mnemonic for Biology & Cell cycle I Prefer Milk And Tasty Cupcakes Interphase Metaphase Telophase Prophase Anaphase Cytokinesis Types of Interference Different leukocyte Never Let Monkeys Eat Bananas Neutrophils (60%) Never Lymphocytes (30%) Let Monocyte (6%) Monkeys Eosinophils (3%) Eat Basophils (1%) Bananas Amoeba Contractile vacuolea Osmoregulation occurs Pseudopodium Projection of cytoplasm that causes movement Plasma membrane Respiration occurs Cytoplasm Nucleus Food vacuole Amoeba Pseudopodia Food vacuole Feeding of Amoeba - (phagocytosis) Reproduction of Amoeba (binary fission) Prey 1 2 3 4 1 2 3 4 Synapse synapse The space between two neurones Chemical Compounds in Cell Chemical components Mineral salts Nucleic acids Organic compounds Non-organic compounds Carbohydrates Water Lipid Protein Must Know 1202 Biology Form 4.indd 3 24/05/2022 10:38 AM
Important Diagrams (Chapter 11) 32 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 6) 26 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 13) 34 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 7) 28 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 15) 36 @ Pan Asia Publications Sdn. Bhd. Important Diagrams (Chapter 8) 30 @ Pan Asia Publications Sdn. Bhd. Relationship between hormones and thickness of uterus 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Menstruation Menstruation Endometrium increases Secretory phase in thickness Thickness of endometrium Uterus Level of hormones from ovary Level of hormones from pituitary gland Ovulation Uterine wall Oestrogen Follicle stimulating hormone (FSH) Luteinising hormone (LH) Progesterone Days in menstrual cycle MUST KNOW Important Diagrams Types of Immunity in Humans Acquired immunity Immunity developed in life Active immunity Immunity acquired after exposed to an infection or getting vaccine Passive immunity Immunity acquired from someone or something Natural Antibodies are made after exposed to infection Natural Antibodies are transmitted from mother to baby Artificial Antibodies are made after vaccination Artificial Antibodies acquired from serum medicine Human Respiratory System Nasal cavity Pharynx Larynx Trachea Lungs Bronchi Bronchiole Alveoli Diaphragm Human Blood Circulatory System Lungs Body Aorta Pulmonary artery Pulmonary circulation Systemic circulation Pulmonary vein Vena cava Right atrium Left atrium Right ventricle Left ventricle Homeostasis Nerve impulse is sent by different neurone 3 Nerve impulse is sent out by motor neurone 4 Response returns to balance 5 Detected by 2 Change in variable 1 Homeostasis Control centre Variable (Normal state) Beyond or Below Receptor Effector Cell Division Prophase Anaphase Cytokinesis Metaphase Meiosis I Meiosis II Telophase Prophase I Mitosis Meiosis Interphase Anaphase I Cytokinesis I Metaphase I Telophase I Prophase II Anaphase II Cytokinesis II Metaphase II Telophase II Must Know 1202 Biology Form 4.indd 6 24/05/2022 10:38 AM
17 Chapter 3 Movement of Substances across the Plasma Membrane NOTES 3.1 Structure of Plasma Membrane 3.2 Concept of Movement of Substances Across a Plasma Membrane Movement of substances across the plasma membrane Osmosis Passive transport • Do not require energy or ATP • Moves down the concentration gradient • Dynamic equilibrium is achieved Active transport • Requires energy or ATP • Moves against concentration gradient • Accumulation or elimination of substances Hypotonic solution – Solution that has lower concentration of solutes than the other solution. Isotonic solution – Solution that has similar concentration of solutes with the other solution. Hypertonic solution – Solution that has higher concentration of solutes than the other solution. Simple diffusion Facilitated diffusion Phospholipid • Hydrophilic head – Polar head that is attracted to water • Hydrophobic tail – Non-polar tail that is not attracted to water Glycolipid – For cell recognisation Cholesterol – Makes the plasma membrane more stable, stronger and flexible Pore protein – Enables small molecules and ions to pass through Carrier protein – As a carrier to transport large molecules such as glucose, amino acids and nucleic acids Phospholipid bilayer – As a barrier to separate both sides of membrance Glycoprotein Globular protein Hydrophobic tail Hydrophilic head Hydrophilic head Peripheral protein Carbohydrate chain Outside plasma membrane Inside plasma membrane C03 1202 Biology Form 4.indd 17 24/05/2022 4:33 PM
95 Chapter 10 Transport in Humans and Animals NOTES 10.1 Types of Circulatory System Heart Haemocoel Gill capillaries Heart 1 ventricle 1 atrium Body capillaries Lung capillaries Heart 1 ventricle 2 atria Body capillaries Lung capillaries Heart 2 ventricle 2 atria Body capillaries Insect Fish Amphibian Human 10.3 Mechanism of heartbeat Blood group compatibility Donor O Recipient A B AB O A B AB Broken vessel Activated platelet Fibrin strands Clotting factor (Thrombokinase) Prothrombin Fibrinogen (soluble) Fibrin (Insoluble) Thrombin Calcium and vitamin K Blood clot Damaged blood vessel Injury to vessel lining triggers the release of clotting factors Formation of platelet plug Vasoconstriction limits blood flow and platelets form a sticky plug Development of clot Fibrin strands adhere to the plug to form an insoluble clot SA node generates electrical impulses SA node AV node The impulse travels along the AV bundle and the bundle branches to the Purkinje fibres to whole ventricle walls Purkinje fibres Bundle branches Moderator band Both ventricles contract simultaneously and blood is pumped out of the heart Stimulus spreads across the atrial surface and reaches the AV node Both atria contract simultaneously and blood is forced into the ventricles AV bundle C010 1202 Biology Form 4.indd 95 20/04/2022 3:15 PM
18SOS TIP3.1 Structure of Plasma Membrane 1. The term ‘fluid’ in the fluid mosaic model refers to A the lipid molecule shows a bit of movement to avoid becoming packed. B the main compartment of the lipid bilayer that contains fluid in mosaic formation. C the ability of the lipid to attract water. 2. The movement of particles through the plasma membrane will be regulated by plasma membrane. Which of the following does not explain the importance of the function of the plasma membrane? HOTS Applying A To provide nutrients for metabolism. B To eliminate toxic waste products. C To secrete useful substances. D To maintain the shape of plant cells. 3. Diagram 1 shows plasma membrane which consists of molecules arranged in a double layer. P Q Diagram 1 The parts labelled as P and Q are A both hydrophobic. B both hydrophilic. C hydrophilic and hydrophobic respectively. D hydrophobic and hydrophilic respectively. 4. • X is a component of plasma membrane. • X is the precursor to synthesize steroid. What is X? HOTS Applying A Triglyceride B Protein C Glycoprotein D Cholesterol PAPER 1 Each question has four different answers A, B, C and D. For each question, choose one answer only. 5. Diagram 2 shows the fluid mosaic model of plasma membrane. W X Y Diagram 2 What is Y? A Pore protein B Carrier protein C Glycoprotein 6. Diagram 3 shows the structure of plasma membrane. R S T U P Q Diagram 3 Which structures are hydrophobic? A P and Q C R and S B Q and S D T and U 7. Diagram 4 shows the structure of plasma membrane. R S T U Diagram 4 Which structure attracts water? A R C T B S D U 8. Structure P makes the plasma membrane become more flexible by strengthening and stabilizing the plasma membrane. What is P? HOTS Applying A Glycolipid B Phospholipid C Cholesterol D Glycoprotein Question 2: Consider the functions of the plasma membrane. Question 4: Steroid needs a substance with two five-carbon rings and two six-carbon rings. Question 8: P is a large, lipid molecule. C03 1202 Biology Form 4.indd 18 24/05/2022 4:33 PM
19 SOS TIP Question 9: Consider the component in the phospholipid molecule. Question 10: Think about the structure of the plasma membrane. Question 12: Consider from the perspective of surface area. Question 16: Consider the contents on both sides. 9. When phospholipid molecules are placed in water, the force that promotes formation of the bilayer is HOTS Applying A the hydrogen bond that exists between phospholipid and water molecules. B the electrostatic force that exists between phospholipid and water molecules. C the hydrophobic interaction between the fatty acid tail and water molecules. D the hydrophilic interaction between charged phospholipid molecules and water molecules. 10. The relative impermeability of membranes to watersoluble molecules is mainly due to the HOTS Analysing A presence of phospholipids in the lipid bilayer B presence of cholesterol on the membranes C presence of large proteins that extend through both sides of the membranes D non-polar nature of water molecules 3.2 Concept of Movement of Substances Across a Plasma Membrane 11. Which of the following substances can be transported by simple diffusion? I Fatty acids III Carbon dioxide II Glucose IV Amino acids A I and II C II and IV B I and III D III and IV 12. Among the types of membrane below, which membrane performs the fastest rate of diffusion? HOTS Analysing A C Membrane with microvilli Membrane with a rounded layer of cells B D Membrane with a villus Membrane with a flat layer of cells 13. Which of the following processes involves the movement of substances across membranes with the help of carrier proteins but without the requirement of energy? A Active transport C Simple diffusion B Osmosis D Facilitated diffusion 14. A concentration gradient exists when HOTS Applying A a semi-permeable membrane is present. B the volume of solution is unequal. C a membrane carries charges. D the solute concentrations on the two sides of a membrane are different. 15. Which of the following diagrams shows osmosis taking place in a root hair of a plant? HOTS Analysing Keys: Solute molecule Water molecule Cell wall and plasm membrane A C Soil Root hair Soil Root hair B D Soil Root hair Soil Root hair 16. Diagram 5 shows a U-tube with two types of solutions and a membrane between them. Semi-permeable membrane 0.5% sucrose solution Q 20% sucrose solution P Diagram 5 At the end of the experiment, HOTS Analysing I the concentration of P is higher than Q. II the water level in P increases while the water level in Q decreases. III the water level in Q increases while the water level in P decreases. IV the osmotic pressure in P is equal to Q. A I and II B I and III C II and IV D III and IV C03 1202 Biology Form 4.indd 19 24/05/2022 4:33 PM
20SOS TIPQuestion 17: Relate to the difference of concentration. Question 19: Relate oxygen to the cellular respiration. Question 21: Take note of the presence of ATP. 17. Diagram 6 shows an experiment with osmosis process. X Y Diagram 6 What would be the correct solutions for X and Y that would cause the water level (indicated by the arrow) in the capillary tube to rise the highest after an hour? HOTS Analysing X Y A 25 % sucrose solution Water B 35 % sucrose solution Water C 25 % sucrose solution 15 % sucrose solution 18. Diagram 7 shows the movement of solute molecules through plasma membrane. Movement of solute molecules Higher concentration of molecules Lower concentration of molecules Diagram 7 What type of movement of molecules are shown in the information given in Diagram 7? HOTS Analysing I Osmosis of water through membrane. II Active transport through active proteins. III Simple diffusion through phospholipid. IV Facilitated diffusion through carrier proteins. A I and II C II and IV B I and III D III and IV 19. Which of the following processes will take place when the root hair cells are deprived of oxygen? HOTS Analysing A Diffusion and osmosis B Diffusion only C Active transport only D Active transport and osmosis 20. How are simple diffusion and facilitated diffusion similar? HOTS Applying I Both processes involve the movement of substances from a region of higher solute concentration to a region of lower solute concentration. II Both processes involve the movement of substances from a region of lower solute concentration to a region of higher solute concentration. III Both processes do not need energy. IV Both processes occur with the help of transport proteins. A I and II C II and IV B I and III D III and IV 21. Diagram 8 shows the active transport of sodium ions across a plasma membrane. Outside of cell Inside of cell Na+ Na+ Na+ ATP Diagram 8 Which of the following is true? HOTS Applying A Sodium ions move from a region of higher solute concentration to a region of lower solute concentration. B Dynamic equilibrium of sodium ions will be achieved at both sides of the cell. C Energy from the ATP (adenosine triphosphate) molecule causes the shape of the carrier protein to change. D The concentration of sodium ions on the outside of the cell is lower than on the inside of the cell. 22. Diagram 9 is a graph that shows the concentration of ions in pond water and in the cell sap of algae that live in the pond. Concentration of ion Pond water Cell sap of Nitella sp. Mineral ions Na+ Keys: K+ Ca2+ Mg2+ Cl– Diagram 9 C03 1202 Biology Form 4.indd 20 24/05/2022 4:33 PM
25 SOS TIP PAPER 2 Section A Answer all questions. 1. Diagram 1 shows two different types of movement of substances across the plasma membrane. Glucose Potassium ion ATP Outside the cell Inside the cell X Y Diagram 1 (a) Based on Diagram 1, what are X and Y? [2 marks] (b) State one characteristic of structure Y. [1 mark] (c) Certain molecules can pass through structure Y by simple diffusion. State one characteristic of these molecules. [1 mark] (d) Glucose molecules and potassium ions are transported across the plasma membrane through the processes shown in Diagram 1. (i) Explain how glucose molecules are transported across the plasma membrane. HOTS Applying [2 marks] (ii) Describe how potassium ions are transported into the cell. HOTS Applying [2 marks] Question 1: (d) (i) Consider the characteristic of the plasma membrane. (ii) Take note of the charge on the potassium ions. C03 1202 Biology Form 4.indd 25 24/05/2022 4:33 PM
26SOS TIP2. Diagram 2.1 shows two regions, X and Y which are separated by a semi-permeable membrane. Region X Region Y Semi-permeable membrane Water molecule Sucrose molecule Diagram 2.1 (a) (i) A dynamic equilibrium is achieved between region X and Y after 30 minutes. Complete Diagram 2.2 by showing: HOTS Analysing • The number of sucrose molecules and water molecules in both regions after 30 minutes. • The level of the solution in both regions after 30 minutes. Region X Region Y Diagram 2.2 [2 marks] (ii) Name the process involved in the result in 2(a) (i). [1 mark] (b) (i) Diagram 2.3 shows the condition of okra after being immersed in tap water. Tap water Initial observation Final observation After being immersed for three hours Okra is cut halfway longitudinally Diagram 2.3 Explain the observation based on Diagram 2.3. HOTS Evaluating [2 marks] (ii) Diagram 2.4 shows a fish immersed in a concentrated salt solution. Initial observation Salted fish After being immersed for three hours Concentrated salt solution Diagram 2.4 Based on Diagram 2.4, explain why salted fish can be stored for four months. HOTS Creating [2 marks] Question 2: (a) (i) Think about the movement of the water and solute particles. (b) (i) Consider the movement of water molecules. (ii) Relate to the process that takes place. C03 1202 Biology Form 4.indd 26 24/05/2022 4:33 PM
27 SOS TIP 3. A small amount of potassium manganate (VII) is put into a beaker of water as shown in Diagram 3.1. At the beginning of experiment Potassium manganate(VII) crystal At the end of experiment Purple solution of potassium manganate(VII) Diagram 3.1 (a) (i) How does the process in Diagram 3.1 occur? HOTS Applying [2 marks] (ii) Several examples of movement of substances in daily life are shown in Table 3.1. In Table 3.1, tick (3) on the correct examples of the process as shown in Diagram 3.1. Table 3.1 A drop of red ink is added into a glass of water, causing the water to turn red. Gaseous exchange between the alveoli and blood cells. Mineral ions move from soil water into the root hair cells. [2 marks] (b) Diagram 3.2 shows the steps in preparing homemade crispy sweet potato chips. 1) Cut the sweet potatoes into thin slices. 2) Soak the sliced sweet potatoes into concentrated salt solution. 3) Rinse a few times and dry the sliced sweet potatoes. 4) Fry the sliced sweet potatoes in hot cooking oil. Diagram 3.2 In your point of view, explain which step is important to produce crispy sweet potato chips. HOTS Creating [3 marks] Question 3: (a) (i) Consider the process of the movement of solute particles. C03 1202 Biology Form 4.indd 27 24/05/2022 4:33 PM
29 SOS TIP SECTION B 5. (a) Explain why plasma membrane is known as a semi-permeable membrane. [5 marks] (b) Diffusion and osmosis are always applied in food industries. Describe how these concepts help in food production. HOTS Analysing [5 marks] (c) Describe how (i) water is absorbed by plant roots. (ii) oxygen is absorbed by Paramecium sp. (iii) iodine is absorbed by an alga (Nitella sp.) which lives in the sea. [10 marks] SECTION C 6. (a) Give the meaning of the terms (i) haemolysis (ii) plasmolysis [4 marks] (b) There are a variety of conditions that may lead to haemolysis of erythrocytes in the human body. Certain medications, infections, toxins, poison or a very low solute concentration may contribute to the premature death of erythrocytes due to haemolysis. Diagram 5.1 is a graph that shows the percentage haemolysis of erythrocytes when the erythrocytes are immersed in sodium chloride solution with different concentrations. Percentage of erythrocytes undergo haemolysis (%) Concentration of sodium chloride solution (%) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10.0 100 80 60 40 20 0 Diagram 5.1 Based on Diagram 5.1, explain how different concentrations of sodium chloride solution affect the condition of erythrocytes. HOTS Analysing [8 marks] (c) Diagram 5.2 shows a plant in one condition. Diagram 5.2 Based on Diagram 5.2, explain what happens to the plant and two possible reasons that cause the plant to have this condition. HOTS Evaluating [8 marks] Question 5: (b) Consider the water content in the treated food. C03 1202 Biology Form 4.indd 29 24/05/2022 4:33 PM
42SOS TIPSECTION C 7. (a) State six properties of water. [6 marks] (b) Briefly describe the significance of water to living organisms. [6 marks] (c) There are several components in cells that forms organic and inorganic compounds. Organic compounds such as carbohydrates, proteins, lipids and nucleic acids are normally found in cells and each of the compound plays an important role in the cells. Explain the importance of carbohydrates and proteins in a cell. HOTS Evaluating [8 marks] 8. Briefly explain the molecular structures, properties and location to find the following substances. (a) Triglycerides [6 marks] (b) Phospholipid [8 marks] (c) Steroid [6 marks] Reinforcement and Assessment of Science Process Skills for Paper 3 (Practical Test) You are required to carry out an experiment to determine the presence of reducing sugar and non-reducing sugar. Procedure: 1. 1 ml of Benedict’s solution and 1 ml of glucose solution are put into the same boiling tube. 2. The solution is heated in a water bath for 5 minutes. 3. The changes that occurred in the contents of the boiling tube are recorded. 4. Steps 1 to 3 are repeated on glucose solution, fructose solution, maltose solution, lactose solution and sucrose solution. 5. The result of the experiment is shown in the following table. Solution Type of sugar Initial colour of solution Colour change of solution Distilled water Glucose Fructose Maltose Lactose Sucrose (a) Complete the table above. [3 marks] (b) Based on the results in the table, state two inferences. [2 marks] (c) State the variables in this experiment. (i) Manipulated variable (ii) Responding variable (iii) Fixed variable [3 marks] (d) Describe how you (i) manipulate the variable (ii) observe the responding variable (iii) set the controlled variable [3 marks] (e) Why is distilled water used in this experiment? [1 mark] (f) State the operational definition for reducing sugar. [1 mark] (g) The mixture of Benedict’s solution and sugar is heated using a water bath. Explain why a water bath is used. [1 mark] (h) State the conclusion for this experiment. [1 mark] Glucose solution + Benedict’s solution Benedict’s solution Water bath Diagram 1 Question 7: (c) Consider the functions of carbohydrates and proteins in the cell. Please download sample data from the QR code at the back cover of this book in order to answer the questions. C04 1202 Biology Form 4.indd 42 27/05/2022 9:55 AM
ii Chapter 3 Note: If you are unable to conduct the experiments described in Page 30, you can answer this question using the sample data obtained from the observation in Table 1 shown below. Table 1 Solution Initial length of potato strip (mm) Final length of potato strip (mm) 30 ml of distilled water 50 50 30 ml of 0.5 M sucrose solution 50 46 30 ml of 1.0 M sucrose solution 50 41 Chapter 4 Note: If you are unable to conduct the experiments described in Page 42, you can answer this question using the sample data obtained from the observation in Table 2 shown below. Table 2 Solution Initial colour of solution Colour change of solution Distilled water Blue Remain blue Glucose Blue Brick-red precipitate Fructose Blue Brick-red precipitate Maltose Blue Brick-red precipitate Lactose Blue Brick-red precipitate Sucrose Blue Remain blue Chapter 5 Note: If you are unable to conduct the experiments described in Page 53, you can answer this question using the sample data obtained from the observation in Table 3 shown below. Table 3 Test tube Temperature (°C) Time taken for the hydrolysis of starch to be complete (minutes) A2 0 Not completed after 10 minutes B2 28 2 C2 37 1 D2 45 3 E2 60 Not completed after 10 minutes Chapter 7 Note: If you are unable to conduct the experiments described in Page 72, you can answer this question using the sample data obtained from the observation in Table 4 shown below. Table 4 Reagent bottle Change in limewater Presence of cockroach Turns cloudy Without cockroach Unchanged Reinforcement and Assessment of Science Process Skills for Paper 3 (Practical Test) SAMPLE DATA Sample Data 1202 Biology F4.indd 2 25/05/2022 11:48 AM
148 Answers Chapter 1 – Chapter 2 CHAPTER 1 Paper 1 1. C 2. A 3. D 4. A 5. D 6. B 7. A 8. D 9. A 10. B 11. A 12. A 13. C 14. C 15. B 16. D 17. B 18. A 19. C 20. B 21. D 22. C 23. D 24. A 25. A 26. B 27. C 28. C 29. B 30. D PAPER 2 SECTION A 1. (a) (i) Presence of yeast in the dough (ii) Size of dough (iii) Initial size of dough (b) The dough with yeast will increase in size after baking. (c) Type of dough Size of dough Dough P (with yeast) Increase in size Dough Q (without yeast) Size remains the same (d) The presence of yeast causes the dough to rise and increase in size. 2. (a) (i) Type of fertilisation (ii) The alleles representing the hereditary traits (iii) Nutrients provided to the plants (b) A cross of tall pea plant with dwarf pea plant results in tall progeny. (c) The data is analyzed using statistics (probability). (d) Results show that the dominant trait would mask the recessive trait in a heterozygous cross but when the heterozygous plants are allowed to self-fertilise, the recessive trait can be recovered. SECTION B 3. (a) Biology is the organized study of life and living things, and the interactions with their natural and physical environment. [2] The study or knowledge of Biology is important because it helps us to better understand the interactions in life. Other than that, it is applied in many fields such as biotechnology, genetic engineering and food technology. Furthermore, it is the core subject in an array of careers such as medicine, nursing and research. (b) The five different fields of study are ecology, botany, zoology, microbiology and biotechnology. [5] (c) The scientific investigation method is the process of gathering facts based on an observable event or phenomenon. In biological research, the first step is to identify the problem. Next, the researcher needs to construct a hypothesis which is a tentative explanation for an observed event. In the third step, the researcher needs to identify and control variables in the experiment by determining the manipulated variable, the responding variable and the fixed variable. After that, plan the investigation which involves collecting relevant information or the scientific background of an experiment, preparing the apparatus and the materials needed, and determining the procedures in conducting the experiment. In the fifth step, the researcher starts to carry out investigation by handling the apparatus, materials and specimens used correctly. Next, the researcher can collect and present data in the experiment accurately. After this step, the researcher needs to analyse data and interpret data by analysing the relationship between the manipulated variable and the responding variable. [2] Finally, the researcher can make conclusion and write a report about the experiment. SECTION C 4. (a) Procedure: 1. Prepare six sets of the apparatus shown in Diagram 1 in the question. The weight and the size of the plant, and the number of leaves should be the same. [2] 2. Place each set 10 cm from the light source. 3. The water temperature in each beaker is maintained at 10°C, 20°C, 30°C, 35°C, 40°C and 50°C respectively. 4. For each set, the number of bubbles released per minute is counted. 5. Record the results in a table. Draw a graph for number of bubbles released per minute against temperature. [2] (b) Manipulated variable: Temperature Responding variable: Number of bubbles released per minute Fixed variable: Carbon dioxide concentration and light intensity (c) Personal protective equipment that can be worn during a surgical experiment is a mask, safety googles, gloves and laboratory coat. These equipment are worn to prevent from direct contact with spurted blood or other bodily fluids. (d) Determine the problem statement, make a hypothesis, plan an investigation, determine and control variables, perform the experiment, collect, analyse, then interpret the data, make an conclusion and write a report. CHAPTER 2 PAPER 1 1. A 2. C 3. D 4. A 5. B 6. B 7. D 8. C 9. A 10. B 11. D 12. A 13. C 14. C 15. A 16. D 17. D 18. B 19. A 20. A 21. C 22. B 23. D 24. D 25. A 26. A 27. B 28. C 29. C 30. A 31. D 32. B 33. A 34. A 35. C 36. D 37. D 38. B 39. C 40. A 41. D 42. B 43. A 44. C 45. A PAPER 2 SECTION A 1. (a) (i) Nucleus (ii) It modifies proteins from the rough endoplasmic reticulum to form glycoproteins. (b) It contains grana with chlorophyll to capture light energy and convert the light into chemical energy (glucose). (c) R will shrink and the cell is plasmolysed. The water diffuses Complete Answers (Paper 1) https://bit.ly/3JtHzOl Answer 1202 Biology Form 4.indd 148 24/05/2022 10:43 AM
154 Reinforcement and Assessment of Science Process Skills for Paper 3 (Practical Test) (a) Solution Type of sugar Initial colour of solution Colour change of solution Distilled water No sugar present Blue Remain blue Glucose Reducing sugar Blue Brick-red precipitate Fructose Reducing sugar Blue Brick-red precipitate Maltose Reducing sugar Blue Brick-red precipitate Lactose Reducing sugar Blue Brick-red precipitate Sucrose Non-reducing sugar Blue Remain blue (b) Reducing sugar is present in the solution. Non-reducing sugar is present in the solution. (c) (i) Type of sugar present (ii) Colour change at the end of experiment (iii) Volume of solution (d) (i) Add the same volume of the different solutions into Benedict’s solution. (ii) Observe the colour change on the mixture. (iii) Replace the sugar solution with distilled water. (e) To act as a control set for the experiment. (f) Reducing sugar is the sugar that undergoes a colour change from blue to brick-red precipitate in the presence of Benedict’s solution. (g) It is easier to maintain constant temperature when using a water bath. (h) Glucose, fructose, maltose and lactose are reducing sugars but sucrose is a non-reducing sugar. CHAPTER 5 PAPER 1 1. A 2. B 3. A 4. C 5. D 6. D 7. C 8. A 9. C 10. A 11. B 12. C 13. D 14. A 15. A 16. D 17. B 18. A 19. C 20. B 21. B 22. C 23. D 24. A 25. A 26. B 27. C 28. C 29. A 30. A PAPER 2 SECTION A 1. (a) (i) Organelle X (nucleus) contains genetic information in the deoxyribonucleic acid that can be transcribed into mRNA, which then carries it out to the cytoplasm. (ii) Protein that is formed at the ribosome enters the rough endoplasmic reticulum and is transported into the Golgi apparatus. The protein will be modified into extracellular enzyme in the Golgi apparatus and then packed into the Golgi apparatus for excretion. (b) + + R Substrate Enzyme + Substrate Enzyme – substrate complex Enzyme + Product Product 2. (a) (i) Lactose (ii) The enzyme is highly specific because it has a specific shape of active site, which means only the shape of substrate X is complimentary to the shape of the active site and fits into it. (iii) Lactase enzyme is not used up or destroyed after the reaction. It can be reused to combine with other substrate molecules for the reaction. (b) Molecule P is an inhibitor. It can mimic substrate X, thus it can compete with substrate X to combine with the lactase enzyme at the active site to slow down or stop the enzymatic reaction. 3. (a) Protease and lipase enzymes can hydrolyse the protein and lipid into their monomers. Hence, the baby can easily consume and digest the food. (b) Enzyme pectinase is applied to the apple juice to break down pectin in the apple juice to make the apple juice looks clear. Other than that, pectinase also increases the yield of apple juices. (c) Enzymes can catalyse biochemical reaction as it can lower the activation energy of the biochemical reaction to speed up the reaction. 4. (a) S1: There are more enzymes compared to substrates and the rate of reaction of enzyme is low. S2: The substrate concentration increases but there are still more enzymes than substrates. S3: The amount of enzymes is equal to the amount of substrates. The rate of reaction approaches maximum capacity. S4: There are more substrates than enzymes and the rate of reaction of enzyme remains at its maximum. (b) All active sites of enzymes have been bound with substrates. Hence, the increase of substrate concentration does not cause the increase of the rate of reaction. (c) Increase the enzyme concentration. The Vmax increases proportionately to the enzyme concentration. Rate of reaction 2 Vmax 2 Vmax 2x enzyme concentration 1x enzyme concentration Substrate concentration Chapter 4 – Chapter 5 Answer 1202 Biology Form 4.indd 154 24/05/2022 10:43 AM
1 Answers CHAPTER 1 Paper 1 1. C Biology is the science of life and living things. 2. A Biology is a branch of scientific knowledge and encompasses manipulative techniques in science. 3. D – 4. A Biology curriculum enables students to understand living things and sharpens students’ thinking. 5. D Biology is the science that covers only living things, and the relationship between all living things and the environment. 6. B Gregor Johann Mendel is the Father of Modern Genetics. 7. A Gynaecology is a medical practice that addresses the health of the female reproductive system. 8. D Kitchen apron is usually for cooking in the kitchen. 9. A Face mask can help to protect the entire face of the researcher. 10. B Materials with a pH value between 5 and 9 will not damage and corrode the laboratory sink. 11. A Category A is sharp wastes. Sharp waste is easy to break the thin containers. Therefore, it needs to be inserted into specially prepared containers. 12. A Microorganisms can only be destroyed at a temperature of 121°C and a pressure of 15 psi for 20 minutes. 13. C Only harmless specimens can be dumped in the bin. 14. C – 15. B – 16. D A good biological drawing requires a label. 17. B – 18. A – 19. C – 20. B – 21. D Magnification factor of drawing = 10 × 10 10 = 10 22. C The control set is a normal experimental set and does not carry out changes to the material used in the experiment. 23. D Conclusions are made based on the situation observed. 24. A – 25. A – 26. B The steps of gathering relevant information, determining the apparatus and materials needed and identifying the variables involved are steps in planning the investigation. 27. C – 28. C – 29. B – 30. D – CHAPTER 2 PAPER 1 1. A Mitochondrion has an oval shape, and two layers of membrane, which is smooth on the outside and folded on the inside. 2. C P is the Golgi apparatus that processes, modifies and packages proteins but Q is the smooth endoplasmic reticulum that synthesizes lipid. 3. D Ribosome is the site to synthesise protein in the cell. 4. A P is cell wall of the plant cell. It allows substances to move through it freely. 5. B Centrioles produce spindle fibres to help the movement of chromosomes during cell division. 6. B Matured erythrocytes do not contain nucleus because it gives more space for haemoglobin. 7. D – 8. C Pancreatic cells contain high amount of rough endoplasmic reticulum to produce digestive enzymes. 9. A Lysosome contains digestive enzymes which also named as hydrolytic enzymes to break down the macromolecules and worn-out organelles. 10. B Organelle P is rough endoplasmic reticulum which function to transport protein which is synthesised by ribosome. 11. D Endurance training increases the number and size of mitochondria. 12. A – 13. C – 14. C – 15. A – 16. D The nucleus has chromosomes that contain ribonucleic acid, while mitochondria and chloroplasts contain little amount of deoxyribonucleic acids. 17. D Rough endoplasmic reticulum transports protein made by ribosomes, and smooth endoplasmic reticulum synthesises and transports lipids. 18. B Cytoplasm can help to fill the whole cell and to maintain the cell shape. 19. A Nucleolus is inside the nucleus and is used to synthesise DNA. 20. A Muscle cell needs large number of mitochondria to produce energy for movement. 21. C A is a nerve cell, B is a white blood cell and D is a sperm cell that are found in a multicellular organism. C is a Paramecium which is a unicellular organism. 22. B In freshwater, Amoeba sp. is hypertonic towards water. The water from the surrounding undergoes osmosis into Amoeba sp. So, Amoeba sp. requires contractile vacuoles to remove excess water from its body. 23. D P is cilium which helps to trap food and assist movement in water. 24. D Pseudopodia can be used for eating during phagocytosis as the pseudopodia engulf the food. 25. A As seawater is hypertonic towards the cytoplasm of Amoeba sp., the water will undergo osmosis to move out of the Amoeba sp. making it shrink. 26. A Phagocytosis is the process involved in eating for Amoeba sp. 27. B Both of them are made up of only one cell. 28. C – 29. C This is an adipose tissue. The adipose tissue helps to store fats. 30. A – 31. D Sperm cells can be found in the male reproductive system and red blood cells can be found in the circulatory system. 32. B Mitochondrion is required in large amounts to provide enough energy to cardiac muscle tissue to function. 33. A Trachea contains epithelial tissue with cilia to filter the dust particles in inhaled air. 34. A Heart contains cardiac muscle tissues, but skeletal muscle tissues are attached to bones. 35. C – 36. D Cartilage is a soft connective tissue to provide protection and support for the body. Chapter 1 – Chapter 2 Answer QR1202 Biology Form 4.indd 1 26/04/2022 5:25 PM