Objective Questions A B C D Choose the best answer. 1. Which of the following are applications of expansion and contraction of matter in our daily life? I Gaps between the metal rails on railway tracks II Saucepans used for cooking III Mercury in blood pressure measuring instruments IV Bimetallic strips in fire alarms A I and II only C II and III only B I and IV only D III and IV only 2. Why did early man rub two sticks together to make a fire? A Rubbing increased the flow of oxygen at the surface of the sticks. B Rubbing generated enough heat to ignite the sticks. C Rubbing encouraged heat to flow through convection. D Rubbing promoted heat transfer through conduction. 3. Water has a specific heat capacity of 4200 J kg–1 °C–1. How much energy is needed to heat 4 kg of water from 30°C to 85°C? A 1.68 × 105 J C 9.24 × 105 J B 2.31 × 105 J D 1.428 × 106 J 4. 12 kJ of heat is required to melt 0.4 kg of solid X at its melting point. What is the specific latent heat of fusion of X? A 0.03 kJ kg–1 C 30 kJ kg–1 B 4.8 kJ kg–1 D 300 J kg–1 5. The changes in the state of a substance are shown below. X and Y are the specific latent heat involved in the change of states. X Y Solid Liquid Gas Which of the following is correct about X and Y? X Y A Specific latent heat is released. Specific latent heat is released. B Specific latent heat is absorbed. Specific latent heat is absorbed. C Specific latent heat is absorbed. Specific latent heat is released. D Specific latent heat is released. Specific latent heat is absorbed. 6. A container has 3 kg of water at 65°C. X of heat is required to increase its temperature to 100°C. Y of heat is required to change all the water to steam at the same temperature. What are the values of X and Y? [Specific heat capacity of water: 4.2 × 103 J kg–1 °C–1; specific latent heat of vaporisation of water: 2.26 × 106 J kg–1] A X = 1.26 × 106 J; Y = 6.78 × 108 J B X = 4.41 × 103 J; Y = 6.78 × 105 J C X = 4.41 × 105 J; Y = 6.78 × 106 J D X = 4.41 × 105 J; Y = 2.373 × 108 J 7. Why does seawater feel cooler than the sand on a beach in the afternoon? A The sand is a solid, but the seawater is a liquid. B The seawater contains salt. C The seawater has a higher specific latent heat compared to the sand. D The specific heat capacity of water is higher than that of sand. Chapter 3 Temperature and Heat 49
8. The figure shows some methods of heat transfer. Method X Method Y Method Z What are methods X, Y and Z? A X = Convection; Y = Conduction; Z = Radiation B X = Convection; Y = Radiation; Z = Conduction C X = Conduction; Y = Convection; Z = Radiation D X = Conduction; Y = Radiation; Z = Convection 9. The figure shows a thermos flask that keeps its contents at a constant temperature for a long time. Which of the following special features can prevent heat loss through convection? A B C D Cork stopper Vacuum Silver-painted surface Plastic container 10. How does a sea breeze occur? I The sea is hotter than the land. II The air above the sea blows towards the land. III The air above the land becomes less dense and rises. IV Sea breeze is caused due to conduction. A I and II only C I, II and III only B II and III only D II, III and IV only 11. The figure shows surfaces of different colours. Which of the surfaces shown above is best at absorbing and emitting heat? Absorb heat Emit heat A Black Silvery B Black Black C White Black D Silvery White 12. The article below is about body temperature regulation. The human body tightly regulates the body temperature through a process called thermoregulation, in which the body can maintain its temperature within specified ranges for physiological functions. The hypothalamus is the coordinating centre for body temperature regulation. As global temperatures rise, it is expected that more heat-related diseases and deaths will occur as heat waves become more common, more severe and longer. Which statements best describe the role of the hypothalamus when the body temperature is too high? I The hypothalamus sends signals to the sweat gland to produce sweat. II The hypothalamus stimulates the blood vessels in the skin to dilate. III The hypothalamus sends signals to muscles, causing them to shiver. IV The hypothalamus reduces the release of thyroid hormones that lower internal metabolism. A I, II and III only C I, III and IV only B I, II and IV only D II, III and IV only 50
Concept Map Complete the concept map below about heat and temperature. types of temperature scales definition a form of measured using through through through affected by Temperature Heat Types of thermometers Heat transfer Heat conductors Heat insulators Thermoregulation Specific heat capacity Solids Sea breeze Land breeze Fluids Natural phenomena Types of surfaces Energy Vacuum Applications Specific latent heat • Specific latent heat of vaporisation • Specific latent heat of fusion Expansion and contraction of solids, liquids and gases Thermometers Body temperature regulation Heat capacity Heat absorption and emission Principle of expansion and contraction of matter • Fahrenheit scale • Réaumur scale • Celsius scale • Kelvin scale A measurement of how hot or cold an object is Conduction Convection Radiation Chapter 3 Temperature and Heat 51
HOTS Daily Application Online Quick Quiz 1. Jamal wants to cook some sweet potatoes at a campfire without the use of any kitchen appliances. The figure shows Jamal’s method of cooking the sweet potatoes. ⎫ ⎬ ⎭ Fire Sand Sweet potatoes Describe how this method can be used to cook the sweet potatoes. The sand is heated by fire through conduction. The heat energy absorbed by the sand is transferred to the sweet potatoes by conduction. As sand is a poor heat conductor, the heat absorbed is released very slowly. This heat is enough to cook the sweet potatoes even if the fire is put out. 2. Uncle Sam wants to paint his house. What paint colour would you suggest to him if he wants his house to be cool during the hot weather? Justify your answer. Light and bright colours such as white and light yellow. These colours are poor heat absorbers, so the house will be kept cool on hot days. 52
Motion and Force CHAPTER 4 4.1 Motion 1. Write ‘L’ for each example of linear motion. Write ‘R’ for each example of rotational motion. (a) The motion of a car on a straight road L (b) The motion of the wheel of a car R (c) The motion of the blades of a helicopter R (d) The motion of a bullet fired from a gun L (e) The motion of a Ferris wheel in an amusement park R (f) The free fall of a stone from a certain height L (g) The motion of the Earth about its own axis R (h) Sliding a door L 2. The figure shows a path travelled by a bus from V to Z. W X V Y Z N 5 km 7 km 5 km 8 km (a) Calculate the distance travelled by the bus. Show your working. VW + WX + XY + YZ = 5 + 7 + 5 + 8 = 25 km (b) Calculate the magnitude of the displacement of the bus. Show your working. VY + YZ = 7 + 8 = 15 km (c) State the direction of the displacement of the bus. To the east Chapter 4 Motion and Force 53
3. Fill in the blanks to show the comparison between distance and displacement. Distance Displacement (a) It is the actual length of the path travelled by the object. It is the shortest distance travelled by the object from the initial to the final position. (b) It is a scalar quantity as it has only magnitude. It is a vector quantity as it has both magnitude and direction. (c) Its magnitude depends on the path followed by the object. Its magnitude does not depend on the path followed by the object. (d) It is always positive . It can be both positive and negative . (e) It can be equal to or greater than displacement. It can be equal to or less than distance. (f) Its SI unit is metre (m) . Its SI unit is metre (m) . (g) Distance = speed × time Displacement = velocity × time 4 (a) (i) What is speed? Speed is the distance travelled per unit time. (ii) Write the formula and SI unit for speed. Speed = Distance travelled Time taken SI unit = Metres per second (m/s) (iii) Is speed a scalar quantity? Why? Yes, it is a scalar quantity because it has magnitude only. (b) (i) What is velocity? Velocity is the displacement per unit time. (ii) Write the formula and SI unit for velocity. Velocity = Displacement Time taken SI unit = Metres per second (m/s) (iii) Is velocity a scalar quantity? Why? No, it is a vector quantity because it has both magnitude and direction. 54
5. A toy car is allowed to roll down a ramp between two timing gates, 100 cm apart, as shown below. 0.00 s Timer Toy car Ramp Timing gate 1 Timing gate 2 The following results were obtained: Distance travelled (cm) Time taken for the toy car to travel from timing gate 1 to timing gate 2 (s) Trial 1 Trial 2 Trial 3 Average time 100 2.50 2.60 2.40 2.50 (a) What is the average time for the toy car to travel from timing gate 1 to timing gate 2? Show your calculation and write the answer in the table above. Average time = 2.50 + 2.60 + 2.40 3 = 2.50 s (b) What is the average speed of the toy car? Average speed = 1 2.50 = 0.4 m/s (c) What will happen to the time taken by the toy car if the distance between the two timing gates is increased to 2 m? The time taken by the toy car increases. (d) What is the reason for carrying out multiple trials of the experiment? To obtain more accurate results and reduce errors. 6. (a) A man runs at an average speed of 3 m/s. What is the distance travelled in 1 minute? Distance = Speed × Time = 3 × 60 = 180 m (b) How long does it take for a vehicle travelling at an average speed of 24 m/s to complete 1800 m? Time = 1800 24 = 75 s Chapter 4 Motion and Force 55
7. Jasin drove from his home to Town Z to visit his grandfather. He passed by Town X and Town Y. The whole journey took him 3 hours. The figure shows the path he took. 44 km Home Town X Town Y Town Z 20 km 80 km 30 km 130 km 80 km (a) What is the total distance travelled by Jasin? Distance = 80 + 30 + 130 = 240 km (b) What is his average speed in km/h? Average speed = 240 3 = 80 km/h (c) What is the magnitude of his displacement? Displacement = 44 + 20 + 80 = 144 km (d) What is the magnitude of his average velocity in km/h? Average velocity = 144 3 = 48 km/h 8. Replace the underlined words with the correct ones. (a) A moving object has a speed of zero. stationary (b) The motion of an object around a circular path from a fixed rotational point is called linear motion. (c) The speedometer in a car shows the average speed of the car. instantaneous (d) As the object moves faster, its trend increases. speed (e) Velocity is the rate of change of distance. displacement (f) An object goes through acceleration when its velocity deceleration decreases. (g) Acceleration is the rate at which speed changes with time. velocity 56
9. A car starts at rest and its speed changes with time. 4 m 8 m 12 m 1 s 1 s 1 s (a) What is the motion experienced by the car? Explain. Non-uniform velocity or acceleration. The speed changes with time. (b) Calculate the motion of the car in (a). Initial velocity = 0 m/s Final velocity = 12 1 = 12 m/s Acceleration = 12 – 0 3 = 4 m/s2 (c) What is the change in velocity of the car per second? 4 m/s 10. The figure shows a velocity-time graph for an object. Velocity (m/s) Time (s) 0 1 2 3 4 5 6 7 8 5 P Q R (a) Which section of the graph shows that (i) the object is moving with uniform velocity? Q (ii) the object is decelerating? R (iii) the object is accelerating? P (b) Calculate the motion of the object from t = 0 s to t = 3 s. Acceleration = 5 – 0 3 = 1.67 m/s2 Chapter 4 Motion and Force 57
(c) Calculate the motion of the object from t = 6 s to t = 8 s. Acceleration = 0 – 5 2 = –2.5 m/s2 Deceleration = 2.5 m/s2 (d) Find the total displacement of the object from t = 0 s to t = 8 s. Displacement = Area under the velocity-time graph = 1 2 × 3 × 5 + (3 × 5) + 1 2 × 2 × 5 = 27.5 m 11. A group of students carries out an activity to study the movement of a trolley down a steep track using a ticker timer. The ticker timer vibrates 50 times per second. The students collect the ticker tape and build a ticker tape chart as shown below. Length of the ticker tape (cm) Time (s) 0 1 2 3 4 5 6 7 0.2 0.4 0.6 0.8 1.0 1.2 (a) Based on the chart, what type of movement did the trolley experience? Increasing velocity or acceleration (b) Calculate the following. (i) The initial velocity of the trolley (ii) The final velocity of the trolley 1-tick interval = 1 50 s = 0.02 s Final velocity = 7 0.2 10-tick interval = 10 × 0.02 = 0.2 s = 35 cm/s Initial velocity = 2 0.2 = 10 cm/s (iii) The average velocity of the trolley Displacement = 2 + 3 + 4 + 5 + 6 + 7 = 27 cm Time = 6 × 0.2 = 1.2 s Or Average velocity = 27 1.2 = 22.5 cm/s Average velocity = Initial velocity + Final velocity 2 = 10 + 35 2 = 22.5 cm/s 58
(iv) The motion of the trolley mentioned in (a), given that the time taken for the velocity change is 1 s. Acceleration = v – u t = 35 – 10 1 = 25 cm/s2 (c) What is the relationship between the length of the ticker tape and time? The longer the length of the ticker tape, the longer the time taken. (d) The ticker tape chart obtained by another group of students is shown below. Length of the ticker tape (cm) Time (s) 0 1 2 3 4 5 6 0.2 0.4 0.6 0.8 1.0 1.2 (i) Based on the chart given, what type of motion did the trolley experience? Decreasing velocity or deceleration (ii) Calculate the motion of the trolley mentioned in (i), given that the time taken for the velocity change is 1 s. Initial velocity = 6 0.2 = 30 cm/s Final velocity = 4 0.2 = 20 cm/s Acceleration = v – u t = 20 – 30 1 = –10 cm/s2 Therefore, Deceleration = 10 cm/s2 Chapter 4 Motion and Force 59
4.2 Force and Motion 1. Fill in the blanks about force. (a) Force is a push or pull upon an object. (b) Force is a vector quantity that has magnitude and direction. (c) The SI unit used in measuring force is newton (N) . (d) Force can produce motion in an object. (e) When two objects interact with each other, the objects experience force . 2. Fill in the space with the terms given that correspond to the description. Buoyant force Frictional force Normal force Gravitational force Elastic force Description Type of force (a) The force that opposes an object’s motion when two surfaces come into contact with one another. Frictional force (b) The force that acts towards the centre of the Earth, causing objects to fall to the ground. Gravitational force (c) The force that acts against an object when an object is in contact with a surface. Normal force (d) The force that is induced through the stretching or compression of a material. Elastic force (e) The force in fluids that acts upwards on an object, causing the object to float. Buoyant force 3. Tick (✓) the activity that requires a push. Cross (✗) the activity that requires a pull. (a) Moving a sofa on the floor ✓ (b) Flying a kite ✗ (c) Moving a shopping cart ✓ (d) Moving a box using a rope ✗ (e) Dragging a piece of luggage ✗ (f) Kicking a ball ✓ Extra Info Force and motion i 60
4. Identify the type of force shown in each of the following figures. Write it in the space provided. Frictional force Elastic force Normal force Gravitational force Weight Buoyant force 5. Fill in the blanks about the effects of force on the shape, position, speed and direction for the following activities. (a) A toy car is placed on the floor, and it is pushed softly. At rest The toy car moves from rest . Force can move a stationary object and change the position of the object. (b) The moving car is pushed harder to move forward . Then, it is pushed from the side. Lastly, the car is obstructed by the hand. Side Q R S In Q, the car moves faster . Force can change the speed of a moving object. In R, force can change the direction of a moving object when it is pushed from the side. In S, the car stops moving. Force can stop a moving object. Chapter 4 Motion and Force 61
(c) A piece of paper is crumpled as shown below. After crumpling the paper, it forms a ball-like structure. Force can change the shape of an object. 6. State ‘True’ or ‘False’ for the following statements. (a) When a force acts on an object, the force can change the shape, size and motion of the object. True (b) A moving ball will move faster when a force is applied in the opposite direction. False (c) Whenever object A exerts a force on object B, object B exerts a force of the same magnitude on object A, but in the horizontal direction. False (d) An object will not change its velocity unless a force acts on the object. True (e) The greater the mass of an object, the smaller the force needed to change its motion. False (f) According to Newton’s Second Law of Motion, a net force on a moving object in the same direction will cause it to accelerate. True (g) Inertia is a property that only applies to objects in motion. False 7. (a) What is Newton’s First Law of Motion known as? Newton’s Law of Inertia (b) What is inertia? The tendency of an object to remain at rest or, if in motion, to continue moving in a straight line at uniform velocity, unless acted upon by an external force. (c) State the relationship between mass and inertia. A heavier object has more inertia than a lighter object. So, the larger the mass of an object, the larger the inertia of the object. 62
8. Tick (✓) the effects of inertia in daily life. (a) An aeroplane needs a long runway to land safely. ✓ (b) When two spheres of different masses are dropped simultaneously from the same height, they take almost the same time to reach the ground. (c) Passengers move forward when a train stops. ✓ (d) When a bus takes a sharp turn, passengers tend to lean sideways. ✓ 9. An experiment is carried out to study the relationship between mass and inertia. A metal block weighing 50 g is hung from a retort stand. The metal block is pushed and the number of oscillations in 20 s is recorded using a stopwatch. The experiment is repeated using different masses of metal blocks. The results are shown in the table below. Mass (g) Number of oscillations in 20 s 50 5 100 10 150 15 200 20 250 25 (a) Draw a graph of the number of oscillations against the mass of the metal block using the data in the table above. Retort stand Metal block String Chapter 4 Motion and Force 63
(b) Based on the graph in (a), state the number of oscillations when the mass of the metal block used is 200 g. Write down your answer in the table. (c) What can you infer from the graph about the relationship between the mass of the metal block and the number of oscillations? The greater the mass of the metal block, the higher the number of oscillations in 20 s. (d) What is the relationship between the mass of the metal block and the inertia of the object? The greater the mass of the metal block, the greater the inertia of the object. 10. Explain each of the following situations. (a) An oil tanker will continue to move even when its engine has been turned off. Explain. It is due to inertia. The oil tanker has a large mass, so it has greater inertia. (b) The figure shows a child and his mother sitting on two identical swings. They are pushed with the same amount of force. Why is it more difficult to move the mother’s swing? The mother has a greater mass than the child, so it is harder to move her swing compared to that of her child because she has more inertia. 11. (a) If the force acting on an object is 20 N and the acceleration is 5 m/s2 , what is the mass of the object? F = ma m = 20 5 = 4 kg (b) What is the acceleration of an object if the force acting on it is 40 N and its mass is 8 kg? F = ma a = 40 8 = 5 m/s2 (c) What is the force acting on a body with a mass of 3 kg and an acceleration of 7 m/s2 ? F = ma = 3 × 7 = 21 N 64
(d) The velocity of a motorcycle increases from 23 m/s to 50 m/s in 9 s. What is its acceleration? Calculate the force acting on it if the total mass of the motorcycle and the rider is 325 kg. Acceleration = 50 – 23 9 = 3 m/s2 F = ma = 325 × 3 = 975 N 12. (a) State Newton’s Third Law of Motion. For every action, there is an equal but opposite reaction. (b) Label the ‘action force’ and ‘reaction force’ in each of the following figures. (i) Spring (ii) (iii) (iv) (v) (vi) Chapter 4 Motion and Force 65
Objective Questions A B C D Choose the best answer. 1. Which of the following pairs is correct? Quantity Type of quantity A Speed Vector B Displacement Vector C Acceleration Scalar D Velocity Scalar 2. Which of the following statements about distance and displacement is correct? I Both have the same SI unit, the metre. II Both have only direction without magnitude. III Both are used to indicate the length between two points. A I and II only C II and III only B I and III only D I, II and III Based on the figure below, answer questions 3 to 5. The figure shows a path taken by Fatima to reach a bank. House Bank 800 m 500 m 900 m 500 m 1.3 km N 3. What is the distance travelled by Fatima from her house to the bank? A 3.9 km C 3500 m B 4 km D 3800 m 4. What is the magnitude of Fatima’s displacement? A 2 km C 1700 m B 3 km D 2700 m 5. What is the direction of Fatima’s displacement? A To the north C To the west B To the south D To the east 6. Janet walks 200 m from point X to point Y. She then returns to point X. What is the total displacement of her journey? A 0 m C 200 m B 100 m D 400 m 7. Jess takes 24 minutes to cycle from her house to the market. If her average speed is 12 km/h, what is the distance of her house from the market? A 3.6 km C 5.4 km B 4.8 km D 6 km Based on the information below, answer questions 8 and 9. The figure shows the path taken by a car travelling from Town P to Town Q. The car travelled 164 km to reach its destination in 120 minutes. Town Q is located 108 km northeast of Town P. Town P Town Q 8. What is the average speed of the car? A 41 km/h C 82 km/h B 54 km/h D 92 km/h 9. What is the average velocity of the car? A 41 km/h C 82 km/h B 54 km/h D 92 km/h 66
10. The figure shows a velocity-time graph for a car. Velocity (m/s) Time (s) 0 5 10 1 2 3 4 5 6 What is the displacement of the car? A 20 m C 30 m B 25 m D 35 m 11. The figure shows the movement of a car when the driver notices a red light ahead. What happened to the car? A Displacement C Acceleration B Uniform velocity D Deceleration 12. What is the force that exists between two surfaces in contact with each other? A Gravitational force B Buoyant force C Elastic force D Frictional force 13. Jane noticed that a spring becomes longer if it is stretched and shorter if it is compressed. What can be inferred from this observation? A Force is measured in newtons. B Force can change the position and speed of an object. C Force can change the shape of an object. D Force can change the shape, position and speed of an object. 14. Which vehicle has the greatest inertia? A A moving bicycle B A flying aeroplane C A moving car D A moving scooter 15. When a magician quickly pulls a tablecloth from a table, the plate remains on the tabletop. Plate Tablecloth Why does the plate remain on the table? A Linear motion C Deceleration B Rotational motion D Inertia 16. A bus is moving along a straight road. A passenger is drinking water from a bottle with a wide opening. The driver slams the brakes when he sees a cat cross the road. What is likely to happen to the water in the bottle? A The water will stay horizontal. B The water will spill over side 1. C The water will spill over side 2. D The water will spill over side 1 and side 2. 17. What is the force applied on an object with a mass of 4 kg and an acceleration of 8 m/s2 ? A 2 N C 32 N B 16 N D 64 N 18. A player hits a ball with a force of 6 N. What force does the bat experience? A 3 N C 12 N B 6 N D 24 N 1 2 Water Bus’s direction Chapter 4 Motion and Force 67
Concept Map Complete the concept map below about force and motion. effects of force types of forces SI unit definition type type Newton’s Laws involves formula involves Force Newton (N) Distance Displacement Speed Velocity Acceleration Deceleration A push or pull acting on an object Newton’s First Law of Motion Newton’s Third Law of Motion Newton’s Second Law of Motion • Gravitational force • Normal force • Elastic force • Frictional force • Buoyant force • Can move a stationary object • Can stop a moving object • Can change the speed of a moving object • Can change the direction of a moving object • Can change the shape or size of an object • Average speed • Instantaneous speed Inertia and mass F = ma Action force and reaction force Motion 68
HOTS Daily Application Cameras installed at 5 km intervals along a road are used to record the average speed of cars. A car is driving on a road that has a speed limit of 90 km/h. The car travels 5 km in 3 minutes. (a) Does the average speed of the car remain under the speed limit? Justify your answer with a calculation. Time = 3 min = 0.05 h Average speed = 5 0.05 = 100 km/h The average speed of the car does not stay within the speed limit. (b) The car’s speedometer records 80 km/h at one point during the journey. Explain why the average speed for the whole journey does not always match the speed recorded on the car’s speedometer. The speedometer of a car reveals information about the instantaneous speed of the car. It shows the speed at a particular instant in time. So, the instantaneous speed of the car is not the average speed. The car’s speed is not always constant. On average, the car is travelling at a speed of 100 km/h. During the journey, there may have been times when the car slowed down and the speedometer recorded 80 km/h at that instant. Online Quick Quiz Chapter 4 Motion and Force 69
1. Which skill is applied when someone is making an initial explanation of an observation? A Making a hypothesis B Making an inference C Predicting D Defining operationally 2. When conducting an experiment, the teacher asked Nadia to measure 50 ml of distilled water. Which of the following apparatus is the most appropriate to use? A Boiling tube B Conical flask C Beaker D Measuring cylinder 3. A honeybee has a mass of 116 mg. It is equivalent to A 1.16 × 102 kg C 1.16 × 10–4 kg B 1.16 × 10–3 kg D 1.16 × 10–5 kg 4. The figure shows an irregular shape on a grid paper. 1 cm 1 cm What is the estimated area of the shape? A 80 cm2 C 88 cm2 B 84 cm2 D 90 cm2 5. The figure shows the arrangement of particles in substance P at room temperature. Substance P is most probably A hydrogen gas B oil C ice D vinegar 6. In which of the following changes of state do the particles change from ‘closely arranged’ to ‘moving fast and freely’? A Liquid to solid B Solid to gas C Solid to liquid D Gas to solid 7. Azmin takes some ice cubes from an ice tray. Ice cubes Which of the following is a property of ice cubes? A They have a high density. B They have a fixed shape. C They have low kinetic energy. D They take the shape of their containers. Assessment 1 Section A [40 marks] Choose the best answer. Answer all questions. 70
8. The figure shows the processes P, Q, R and S that occur when a substance changes states. P R Q S Solid Liquid Gas Which of these processes occur in each of the following situations? I The level of water in a pond decreases when exposed to the hot sun. II A candle melts. III Dew forms on the grass in the morning. IV Ice cubes form in a freezer. I II III IV A Q P S R B P Q S R C Q P R S D R P S Q 9. The table below shows the densities of four substances P, Q, R and S. Substance Density (g/cm3 ) P 0.2 Q 2.4 R 0.9 S 7.8 Which substance(s) will sink in water if the density of water is 1.0 g/cm3 ? A P only C Q and S only B P and R only D S only 10. The figure shows a bimetallic strip. Copper Iron What happens when the bimetallic strip is heated? A The bimetallic becomes longer. B The bimetallic strip bends with copper outside and iron inside. C The bimetallic strip remains the same. D The bimetallic strip bends with iron outside and copper inside. 11. Andy sits by a campfire to stay warm. What type of heat transfer is Andy experiencing? A Conduction B Convection C Radiation D All of the above 12. The specific heat capacity of water is 4200 J kg–1 °C–1. How much energy is required to heat 5 kg of water from 20°C to 70°C? A 4.2 × 105 J C 1.05 × 106 J B 5.25 × 105 J D 1.47 × 106 J 13. What is the specific latent heat of fusion of P if it takes 15 kJ of heat to melt 0.6 kg of solid P at its melting point? A 250 J kg–1 C 25 kJ kg–1 B 9 kJ kg–1 D 50 kJ kg–1 14. Which of the following statements about land breeze is true? A The sea is cooler than the land. B The air above the land blows towards the sea. C The air above the land becomes less dense and rises. D Land breeze blows during the day. Assessment 1 71
15. Azmir rides a bicycle along a path from V to Z as shown. The total time taken by Azmir is 30 seconds. V N W X Y Z 70 m 50 m 40 m 20 m What is the average speed of Azmir? A 4 m/s B 5 m/s C 6 m/s D 10 m/s 16. A vehicle moves from P to Q as shown below. Engine oil drips from the vehicle at equal time intervals along PQ. Engine oil drop Q P What is the motion experienced by the vehicle? A At rest B Moving with constant velocity C Acceleration D Deceleration 17. How long does it take a bird flying at 25 km/h to travel 150 km? A 3 hours B 6 hours C 8 hours D 12 hours 18. The figure shows a section of a ticker tape that recorded the motion of a toy car. The ticker timer makes 50 dots per second. 1.8 cm 1.2 cm Direction of motion Which of the following statements is correct? A The acceleration is 30 cm/s2 . B The initial velocity is 90 cm/s. C The initial velocity is 60 cm/s2 . D The final velocity is 90 cm/s. 19. Which of the following ticker tapes best shows an object moving fast at a constant velocity? A Direction of motion B Direction of motion C Direction of motion D Direction of motion 20. A car is travelling with a velocity of 24 m/s and it takes 12 s to stop after applying the brakes. What is the force exerted by the car’s brakes if the mass of the car and the driver is 1100 kg? A 550 N B 2200 N C 2400 N D 4400 N 72
Section B [60 marks] Answer all questions. 1. The figure shows a triangle and a leaf drawn on grid paper. 1 cm 1 cm (a) The area of the triangle can be calculated using a mathematical formula. Give your inference regarding the shape of the triangle. It has a regular shape. [1 mark] (b) Calculate the area of the triangle. Area = 1 2 × 8 × 9 = 36 cm2 [1 mark] (c) Can you calculate the area of the leaf using a mathematical formula? Why? No. It has an irregular shape. [2 marks] (d) Find the estimated area of the leaf. About 29 cm2 [1 mark] (e) Based on your answer in (d), do you think the estimated area of the leaf is less or more than its actual area? Explain your answer. It is less than its actual area because only grid squares that are fully covered, half-covered, and more than half-covered are counted. Grid squares that are less than half-covered are not counted. [2 marks] (f) If the grid of the graph paper is changed to 1 mm × 1 mm, what would happen to the estimated area of the leaf? The estimated area of the leaf will be more accurate. [1 mark] Assessment 1 73
2. The figure shows an activity to determine the volume of a marble and an irregularshaped stone. The marble has a mass of 24 g. 50 mℓ 40 30 20 10 50 mℓ 40 30 20 10 50 mℓ 40 30 20 10 22 cm3 Water 28 cm3 35 cm3 Water Marble Marble Stone (a) What method was used in this activity? Water displacement method [1 mark] (b) Based on this activity, (i) what is the volume of the marble? Volume = 28 – 22 = 6 cm3 [1 mark] (ii) what is the density of the marble? Density = 24 6 = 4.0 g cm–3 [2 marks] (iii) what is the volume of the stone? Volume = 35 – 28 = 7 cm3 [1 mark] (c) The table shows four types of liquids and their densities. Liquid Oil Seawater Pure water Mercury Density (g cm–3) 0.91 1.03 1.00 13.60 All the liquids are placed in a beaker as in the figure below. Label the figure using the information from the table above. [2 marks] 74
3. The figure shows the processes of changing states of matter that occur around us. R Q P Solid Liquid Gas (a) Draw the arrangement of particles in solid, liquid and gas. State one physical property of each state of matter. State of matter Arrangement of particles Physical property Solid Cannot be compressed (any suitable answer) Liquid Cannot be compressed to any extent (any suitable answer) Gas Can be compressed easily (any suitable answer) [3 marks] (b) Compare the particle movements between a solid and a gas. The particles in a solid can only vibrate and rotate about fixed positions, whereas the particles in a gas move randomly, freely and at very high speeds. [2 marks] (c) Based on the figure above, name processes P, Q and R. P: Melting Q: Condensation R: Deposition [3 marks] (d) State one example of a natural phenomenon that involves process Q. Formation of dew/formation of clouds [1 mark] Assessment 1 75
4. A solid substance X with a mass of 800 g is heated by a heater that gives out heat at the rate of 64 J/s. The initial temperature of substance X is 0°C. The heating curve of the substance is shown below. Time (min) Temperature (°C) 1 0 P Q R S T U 2 3 4 5 6 7 8 9 20 40 60 80 100 (a) What is the melting point of substance X? 20°C [1 mark] (b) Why does the temperature in stage QR remain constant even though the heater keeps heating the substance? The heat absorbed is used to overcome the attractive forces between the particles. [1 mark] (c) Calculate the specific heat capacity of substance X in the solid state. Heat supplied = mcθ 64 × 60 × 1 = 0.8 × c × (20 – 0) c = 3840 16 = 240 J kg–1 °C–1 [2 marks] (d) Calculate the specific heat capacity of substance X in the liquid state. Heat supplied = mcθ 64 × 60 × (5 – 2) = 0.8 × c × (80 – 20) c = 11 520 48 = 240 J kg–1 °C–1 [2 marks] (e) Calculate the specific latent heat of fusion of substance X. Heat supplied = mL 64 × 60 × (2 – 1) = 0.8 × L L = 3840 0.8 = 4800 J kg–1 [2 marks] 76
(f) Calculate the specific latent heat of vaporisation of substance X. Heat supplied = mL 64 × 60 × (7 – 5) = 0.8 × L L = 7680 0.8 = 9600 J kg–1 [2 marks] (g) What is the boiling point of substance X? 80°C [1 mark] 5. Three similar cars in different colours were parked in an open car park on a hot day. The temperature inside each car was measured after a few hours. Red Yellow Black (a) Atifa accidentally mixed up the results. Help Atifa sort out the results in the table below. Temperature (ºC) 38 30 32 Colour of car Black Yellow Red [3 marks] (b) Give the principle you used to find the answer in (a). The principle of heat emission and absorption [1 mark] 6. The figure shows a graph of velocity (v) against time (t) for a moving vehicle. Velocity (m/s) Time (s) 0 5 P Q R S 4 8 12 16 20 10 12 15 (a) Which part of the graph shows that the vehicle is moving with uniform velocity? PQ [1 mark] (b) State the time interval when the vehicle is undergoing deceleration. From t = 12 s to t = 15 s [1 mark] Assessment 1 77
(c) Determine the deceleration of the vehicle. Acceleration = 0 – 20 3 = –6.67 m/s2 Deceleration = 6.67 m/s2 [2 marks] (d) What is the acceleration of the vehicle from t = 0 s to t = 5 s? Acceleration = 12 – 0 5 = 2.4 m/s2 [2 marks] (e) Find the displacement of the vehicle from P to R. Displacement = Area = [12 × (12 – 5)] + 1 2 × (12 – 10) × (20 – 12) = 84 + 8 = 92 m [2 marks] (f) Find the average velocity of the vehicle from t = 0 s to t = 12 s. Displacement = area = 1 2 × 5 × 12 + 92 = 122 m Average velocity = 122 12 = 10.17 m/s [2 marks] 7. The figure shows the ticker tape that was produced by a toy car moving up a slope. The ticker timer produces 50 ticks per second. The ticker tape was cut into five sections as shown below. Section A 5 cm Section B 4 cm Section C 3 cm Section D 2 cm Section E 1 cm (a) Based on the ticker tape, build a ticker tape chart that shows the motion of the toy car. Every section of the tape contains 5 ticks. [3 marks] 78
(b) Based on the ticker tape chart in (a), what is the motion of the toy car? The toy car is moving with decreasing velocity or it is decelerating. [1 mark] (c) Find the total displacement of the toy car. Displacement = 5 + 4 + 3 + 2 + 1 = 15 cm [2 marks] (d) Find the average velocity of the toy car. 1-tick interval = 1 50 s = 0.02 s 5-tick intervals = 5 × 0.02 = 0.1 s Time taken = 5 × 0.1 = 0.5 s Average velocity = 15 0.5 = 30 cm/s [2 marks] (e) Find the deceleration of the toy car, given that the time taken for the velocity change is 0.4 s. Initial velocity = 5 0.1 = 50 cm/s Final velocity = 1 0.1 = 10 cm/s Acceleration = 10 – 50 0.4 s = –100 cm/s2 Deceleration = 100 cm/s2 [2 marks] (f) What is meant by deceleration? Deceleration is the opposite of acceleration. When the velocity decreases, the acceleration is negative. This is called deceleration. It is the rate by which the velocity of a motion decreases. [1 mark] Assessment 1 79
Living Things CHAPTER 5 5.1 Biodiversity 1. What do you understand about the term ‘biodiversity’? The variety of organisms on Earth, comprising the different types of plants, animals and microorganisms 2. Which of the following statements is correct about biodiversity? Tick (✓) the correct answers. It encompasses different types of living and non-living things. ✓ It encompasses the different species of plants, animals and microorganisms. ✓ It concerns all living things with different characteristics. ✓ It is a result of diverse climates and habitats. ✓ Tropical rainforests generally have high levels of biodiversity. Biodiversity conservation is a trend adopted by developed countries. 3. Indonesia is a habitat of a wide range of endemic species. Unfortunately, these endemic species are on the brink of extinction. (a) What are endemic species? Endemic species are plants and animals that exist only in one geographic region or a particular area. (b) Suggest two measures that can be taken to protect the endemic species from extinction. Establishing rehabilitation centres to care for endemic species and repopulating their original habitats. Protecting endemic species by prohibiting the killing and trading of these species, and imposing penalties for the offence. (c) The 2018 Asian Games chose endemic species such as the bird of paradise ‘Bhin Bhin’, the single-horned Javan rhinoceros ‘Kaka’ and the Bawean deer ‘Atung’ as its official mascots. In your opinion, why were the endemic animals chosen? As a means of introducing the unique endemic species in Indonesia to the younger generation and raising awareness of wildlife conservation. 80
4. The figure shows the human activities that will destroy biodiversity if uncontrolled. Activity X Activity Y (a) Name activities X and Y. X: Deforestation Y: Illegal hunting (b) What are the negative effects of these activities on biodiversity? X: Plants and animals are losing their habitats and facing extinction. Y: The number of animals is decreasing and some are threatened with extinction. (c) What are the other two human activities that can endanger biodiversity? Logging and overfishing (d) The government has taken steps to ensure that biodiversity is managed effectively. Law enforcement is one of them. The government also regularly conducts public awareness campaigns to educate society about the importance of biodiversity conservation. In your opinion, which measure is more effective? Justify your opinion. Law enforcement is more effective because imposing severe punishments, such as imprisonment or heavy fines, deters people from breaking the law. / Awareness campaigns are more effective because they can help change the views of the public and make people more conscious of their responsibilities towards the conservation of biodiversity. (e) Besides the measures given in (d), suggest another two measures to protect biodiversity. Replanting trees of the same species to replace those that were cut down in order to preserve the tree species. Creating national parks, forest reserves, marine parks and wildlife sanctuaries to protect flora and fauna habitats. (f) State two reasons why biodiversity is important. Provides food for humans and other organisms. Plants take in carbon dioxide from the air and release oxygen into it. Chapter 5 Living Things 81
5.2 Living and Non-living Things 1. Tick (✓) the correct statements and cross (✗) the incorrect statements about living and non-living things. (a) All living things are made of cells, use energy, respond to stimuli, grow and reproduce, exhibit movements and excrete. ✓ (b) A non-living thing is anything that was never alive. ✓ (c) Breathing enables living things to acquire energy, which is used by cells to perform their functions. ✓ (d) Living things digest food for energy and also excrete waste from their bodies. ✓ (e) Non-living things do not eat, grow, breathe, move and reproduce. ✓ (f) Both living and non-living things have a lifespan. ✗ (g) After a period of time all living things mature and die. ✓ (h) All non-living things can replicate themselves and make many copies. ✗ 2. Compare the characteristics of living and non-living things. Living things Characteristic Non-living things Yes Need food No Yes Need air No Yes Obtain energy from food No Yes Able to move No Yes Can grow No Yes Produce offspring No Yes Produce and able to remove waste products No Yes Respond to changes in the surroundings No Yes Made up of cells No 82
3. Fill in the blanks about the characteristics of living things. (a) Living things take in oxygen from the atmosphere. The oxygen is used to break down the food they eat to produce energy . This process of releasing energy from food is known as respiration . Living things use the energy to perform their life processes. (b) The process by which an organism uses food to support its life is called nutrition . Humans and animals cannot make their own food—they must eat plants and other animals to get the nutrients needed. (c) By moving , animals are able to catch their prey or find food, escape or hide from enemies , get shelter and find mates to have young. Living things can move some or all of their body parts. (d) The process in which waste products are removed from an organism is called excretion . The skin eliminates excess water and salts in sweat. The lungs exhale water vapour and carbon dioxide . The kidneys remove waste products and excess fluids from the body as urine . (e) The process whereby living organisms increase in body size, mass and the number of body cells over time is called growth . All living things are capable of reproducing. The process by which living things give rise to offspring is called reproduction . (f) All living things are able to respond to stimuli in their environment. They respond to changes in light, heat, sound or touch. Chapter 5 Living Things 83
5.3 Classification of Living Things 1. (a) What is the scientific term that identifies different organisms, classifies them and names them? Taxonomy (b) State two importance of the classification in (a). Can identify organisms easily and accurately Ensure that different types of organisms have different names 2. (a) Complete the flow chart below to show the correct order for the levels of the Linnaeus’s taxonomic hierarchy system. Levels Humans General Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Specific Species sapiens (b) Fill in the blanks in (a) using the following terms to show how humans are classified based on this taxonomic hierarchy system. Homo Primates sapiens Chordata Mammalia (c) (i) Carl Linnaeus developed a system in which each species is given a scientific name. What is this system called? Linnaeus binomial system/Binomial nomenclature system (ii) What does an organism’s scientific name consist of? Genus name and species name (iii) What is the scientific name for humans? Homo sapiens 84
3. What are the five kingdoms of living things? Monera, protists, fungi, animals and plants 4. The figure shows three types of microorganisms. P Q R (a) What kingdom do microorganisms P, Q and R belong to? P: Monera Q: Protists R: Fungi (b) (i) What is microorganism P? Bacteria (ii) Does it have a nucleus? No (iii) How many cells does each microorganism P have? One cell/single cell (c) (i) What is microorganism Q? Paramecium (ii) Microorganism Q has tiny hair-like projections surrounding its cell. What are these structures? Cilia (iii) Where would you find microorganism Q? It can be found in fresh water, marine environments and brackish water. (d) (i) What method does microorganism R use to reproduce? Budding (ii) What is the process microorganism R uses to convert sugars into alcohol? Fermentation (iii) Give two uses of microorganism R. Used in making baked foods Used in making alcoholic beverages such as beer and wine 5. Bacteria can be harmful, but some species of bacteria are needed to keep us healthy. (a) Tick (✓) the good bacteria. ✓ Lactobacillus Salmonella ✓ Bifidobacterium ✓ Lactococcus Campylobacter Escherichia coli Chapter 5 Living Things 85
(b) Give two examples of how bacteria can be beneficial to humans. Used in making dairy products such as cheese and yogurt Used in making antibiotics (c) Why are some bacteria called pathogenic bacteria? They cause diseases and illnesses. (d) State one method that can be used to grow bacteria in a laboratory. Using nutrient agar 6. The underlined words are incorrect. Replace them with the correct words. (a) Most motile bacteria move by means of cilia. flagella (b) Eukaryotes are organisms that are so tiny that they cannot be seen without a microscope. Microorganisms (c) Bacteria are multicellular organisms that are found almost everywhere on Earth. unicellular (d) Euglena belongs to the kingdom Monera and has chlorophyll to make its own food. Protista (e) An amoeba is a single-celled animal with the ability to change shape. organism (f) Moulds are microscopic bacteria that live on plant or animal matter. fungi (g) Most fungi grow as thread-like filaments called pseudopodia. hyphae (h) Each yeast cell has a chloroplast, cytoplasm and a membrane that is surrounded by a cell wall. nucleus (i) The algae found on spoiled food could be dangerous, causing food poisoning and symptoms such as stomach pain, vomiting and diarrhoea. mould (j) Plasmodium is a parasitic bacteria that causes malaria in humans. protozoan 7. (a) What are vertebrates? Animals that have a backbone (b) What are invertebrates? Animals that do not have a backbone 86
8. Complete the chart below on the classification of animals. Echinoderms Arthropods Nematodes Reptiles Molluscs Vertebrates Amphibians Invertebrates Birds Annelids 9. The figure shows some animals in their habitat. Chameleon Tortoise Deer Snake Catfish Frog Toucan (a) Classify the animals into the following groups. Mammals Amphibians Reptiles Birds Fish Deer Frog Tortoise, snake, chameleon Toucan Catfish Extra Info Vertebrates and invertebrates i Mammals Reptiles Cnidarians Platyhelminthes Amphibians Echinoderms Poriferans Birds Nematodes Molluscs Fish Annelids Withs jointed legs Arthropods Vertebrates Animals Invertebrates Without jointed legs Chapter 5 Living Things 87
(b) Which animal breathes through its lungs and moist skin? Frog (c) Which animal gives birth to their young and feeds them milk? Deer (d) Which animals reproduce by laying hard-shelled eggs? Tortoise, snake, chameleon (e) Which animal is covered with feathers? Toucan (f) Underline the correct answer describing the characteristics of a snake. (i) The body of a snake is covered in (scales / feathers / fur). (ii) A snake cannot regulate its body temperature because it is (warm-blooded / cold-blooded / homeothermic). 10. Tick (✓) the correct statements and cross (✗) the incorrect statements about vertebrates. (a) Fish are cold-blooded animals that breathe through their gills. ✓ (b) Birds are warm-blooded and have hollow bones. ✓ (c) Amphibians have rough skin and their bodies are covered with scales. ✗ (d) Reptiles have dry, scaly skin and lay eggs. ✓ (e) Bats are the only mammals that can fly. ✓ (f) Birds are covered with hair or fur to keep them warm. ✗ 11. The figure shows a vertebrate that is classified as an amphibian. (a) State two characteristics of the vertebrate. Moist skin Cold-blooded (b) Write the correct answer in the table below. Function of the structure Structure Helps the vertebrate get oxygen from the water. Gills Helps the vertebrate to swim. Tail 88
12. Dugongs are aquatic animals that live in the sea while bats are small animals that are able to fly. (a) While classifying vertebrates, Azmin classified dugongs as fish and bats as birds. Do you agree with him? Explain your answer. Disagree. Dugongs and bats have significant characteristics of mammals. They have fur, are warm-blooded, breathe through their lungs, carry out internal fertilisation, give birth and breastfeed their young. (b) Name two other animals from the same group as the animals shown above. Whales and dogs 13. The figure shows different types of organisms. Dragonfly Starfish Eagle Tapeworm Lizard (a) State the best method to classify the organisms above. Classify them into vertebrates and invertebrates (b) Based on your answer in (a), build a table to classify them. Vertebrates Invertebrates Eagle, lizard Dragonfly, starfish, tapeworm (c) (i) Which organism has an exoskeleton? Dragonfly (ii) What animal group does the organism in (i) belong to? Arthropod (d) (i) What animal group does the starfish belong to? Echinoderm (ii) State one characteristic of the starfish. It features a radial symmetry star-shaped pattern. (Any suitable answer) (e) Which organism has an unsegmented body? Tapeworm Chapter 5 Living Things 89
14. Some animals are found in a habitat. The animals include a parrot, a duck, a bee, a flying fish and a sea lion. The flow chart shown below is used to identify the animals. Does it have a pair of wings? Is its body covered in feathers? Does it have webbed feet? Is its body covered with scales? Yes Yes Yes Yes No No No No R S P T Q Animal (a) Based on the information given above, identify animal P: Bee Q: Parrot R: Duck S: Flying fish T: Sea lion (b) Which of the animals above is an invertebrate? Bee (c) Which of the animals above breathe through lungs? Parrot, duck, sea lion 15. The figure below shows a type of organism X, which is also the animal with the most species known on Earth. (a) Based on your observation, tick (✓) the characteristics of organism X. Has a backbone Has a hard exoskeleton ✓ Has three pairs of legs Has more than three pairs of legs ✓ Has segmented body with jointed legs ✓ Has two antennae 90
(b) What animal group does organism X belong to? Arthropod (c) Tick (✓) the organisms below that are in the same group as organism X. Explain your answer. Scorpion ✓ Sea urchin Crab ✓ Octopus Reason: The scorpion, crab and organism X are all invertebrates with segmented bodies, jointed legs and exoskeletons. 16. Match each invertebrate with the correct group. 17. Tick (✓) the correct statements and cross (✗) the incorrect statements about invertebrates. (a) Cnidarians are invertebrates with spores all over their bodies. ✗ (b) Platyhelminthes do not have a body cavity, and their bodies are soft and unsegmented. ✓ (c) Nematodes are segmented and have a very soft covering. ✗ (d) Echinoderms generally have hard, spiny skin. ✓ (e) Arthropods have bilateral symmetry and jointed legs. ✓ (f) Annelids have legs and hard skeletons. ✗ (g) Molluscs typically protect their soft bodies with a shell. ✓ (h) Sponges are generally aquatic organisms with a sponge-like structure. ✓ Roundworm Scorpion Sea anemone Snail Leech Sea urchin Centipede Arthropods Echinoderms Nematodes Jellyfish Earthworm Sponge Praying mantis Pinworm Octopus Flatworm Annelids Platyhelminthes Poriferans Cnidarians Molluscs Chapter 5 Living Things 91
18. (a) Complete the chart below on the classification of plants. Dicotyledons Mosses Conifers Ferns Plants Non-flowering plants Monocotyledons Flowering plants (b) Define monocotyledons and dicotyledons. Monocotyledons are plants with one cotyledon while dicotyledons are plants with two cotyledons. (c) State two characteristics of monocots: Have fibrous roots/leaves of parallel veins/most of them have non-woody stems dicots: Have taproots/leaves of a network of veins/usually woody (d) How do the following plants reproduce? (i) Mosses: Spores (ii) Ferns: Spores (iii) Conifers: Cones 19. Observe the following plants and classify them using the dichotomous key. Maize plant Pine tree Hibiscus plant Moss Fern Dichotomous key 1 (a) Has flowers ....................................... go to 2 (b) Does not have flowers ...................... go to 3 2 (a) Monocotyledon ................................ maize plant (b) Dicotyledon ...................................... hibiscus plant 3 (a) Produces cones ................................ pine tree (b) Does not produce cones .................. go to 4 4 (a) Vascular............................................. fern (b) Non-vascular .................................... moss Extra Info Dichotomous key i 92
Objective Questions A B C D Choose the best answer. 1. Consider the following statements with reference to biodiversity in Indonesia. I Indonesia’s rainforests are home to a high variety of species, including many endemic species. II The number of animal species documented in Indonesia is higher than the number of plant species. III The main factors affecting biodiversity loss in Indonesia are habitat loss, invasive species, overexploitation, pollution and climate change. Which of the statements given above are true? A I and II only C II and III only B I and III only D I, II and III 2. Which of the following shows the importance of biodiversity? I It provides raw materials to industries. II It provides us with fresh air. III It is a source of medicine. IV It is a source for game hunters. A I and II only B I and III only C I, II and III only D I, II, III and IV 3. Which of the following shows the characteristics of living things? I They obtain energy from food. II They grow and have a very long lifespan. III They respond to changes in the environment. IV They excrete to remove waste products. A I, II and III only B I, III and IV only C II, III and IV only D I, II, III and IV 4. Which of the following groups has the greatest number of organisms? A Family C Class B Order D Phylum 5. If two organisms belong to the same phylum, they must also be in the same A kingdom C class B family D species 6. A tiger is classified as the following: Eukarya, Animalia, Chordata, Mammalia, Carnivora, Felidae, Panthera, Panthera tigris Which one is the family? A Chordata C Carnivora B Mammalia D Felidae 7. The figure shows the structure of a microorganism. Which of the following statements correctly describes the microorganism? A It is the largest microorganism. B It is a bacterium that infects animals. C It is a single-celled animal that is very small in size. D It reproduces by producing spores. 8. Which of the following statements is incorrect about bacteria? A They have no nucleus. B They are unicellular. C They are eukaryotic. D They lack chloroplasts. Chapter 5 Living Things 93
9. Madam Sim wants to make soft bread. Which of the following microorganisms is used in the bread making? A Protozoa C Bacteria B Yeast D Fungi 10. The following diseases are caused by a group of microorganisms, X. • Tuberculosis • Syphilis What is the group of microorganisms, X? A Protozoa C Bacteria B Fungi D Viruses 11. Which of the following organisms is matched with the correct group? Organism Group A Bat Bird B Sea lion Mammal C Turtle Reptile D Polar bear Amphibian 12. The figure shows two animals that live in the sea. The animals can be classified as A fish C amphibians B mammals D reptiles 13. Animal X has the following characteristics. • Has an exoskeleton • Has a segmented body with jointed legs What type of animal could Animal X be? A Flatworm B Sponge C Leech D Millipede 14. The list of common characteristics of a group of vertebrates P is shown below. • Undergo internal fertilisation • Cold-blooded • Their bodies are covered with scales • Lay leathery or hard-shelled eggs What is this group called? A Bird C Amphibian B Fish D Reptile 15. Which of the following statements about amphibians is not correct? A They are cold-blooded animals. B The adults only breathe through their gills. C They reproduce by laying eggs. D They have moist skin. 16. What is the difference between birds and mammals? Birds Mammals A Cold-blooded Warm-blooded B Breathe through skin Breathe through lungs C Have feathers on their bodies Have hair or fur on their bodies D Have two legs Have four legs 17. Why is the tomato plant classified as a dicotyledon? A It has five-petalled flowers. B It has leaves of a network of veins. C It has seeds with one cotyledon. D It has fibrous roots. 18. What is a dichotomous key used for? A To identify an organism B To locate an organism C To name an organism D To interbreed species 94
Concept Map Complete the concept map below about living things. are classified into are classified into Monocotyledons Effective biodiversity management Importance of biodiversity Endemic species Monera (bacteria) Flowering plants Fungi Protists Mammals Arthropods Reptiles Cnidarians Amphibians Echinoderms Birds Nematodes Platyhelminthes Fish Annelids Poriferans Molluscs Animals Plants Dicotyledons Mosses Conifers Ferns Classification of living things Linnaeus’s taxonomic hierarchy system Binomial nomenclature system Dichotomous key • Respiration • Nutrition • Movement • Excretion • Growth • Reproduction • Responding to stimuli Vertebrates Invertebrates Five kingdoms Biodiversity characteristics using are identified using Non-flowering plants Living things Chapter 5 Living Things 95
HOTS Daily Application The variety of organisms on Earth, which includes plants, animals and microorganisms, is referred to as biodiversity. Classification is very important as it deals with the systematic arrangement of organisms for further studies. As we continue to discover new species, we learn better ways of evaluating relationships between species. We share the information globally, which makes it is important to have systems in place to identify and classify organisms. BIODIVERSITY A dichotomous key makes it easier to identify an unknown organism based on their characteristics. It is a series statements consisting of two choices that describe characteristics of the unknown organism. You are given a list of organisms below. Create a dichotomous key to identify the organisms based on their characteristics. Frog, snake, centipede, bat, jellyfish Note: There are a variety of ways to create a dichotomous key. Dichotomous key 1 (a) Has a backbone .................................................................................. go to 2 (b) Does not have a backbone ................................................................. go to 3 2 (a) Warm-blooded.................................................................................... bat (b) Cold-blooded ..................................................................................... go to 4 3 (a) Has a segmented body ....................................................................... centipede (b) Does not have a segmented body...................................................... jellyfish 4 (a) Has scales on its body......................................................................... snake (b) Has no scales on its body.................................................................... frog Online Quick Quiz 96
Interactions Among Organisms and the Environment CHAPTER 6 6.1 Biotic and Abiotic Components 1. Fill in the terms given that correspond to the descriptions. Population Decomposers Community Consumers Species Producers Habitat Ecosystem (a) Animals that eat other organisms (plants or animals) Consumers (b) Organisms that decompose dead organisms into simple substances Decomposers (c) A group of organisms with common characteristics that can breed among themselves to produce offspring Species (d) A few populations of different organisms living together in the same habitat Community (e) An organism’s natural surroundings Habitat (f) All green plants that can make their own food through photosynthesis Producers (g) A few communities living together in one habitat and interact with each other, including the non-living components Ecosystem (h) A group of organisms of the same species that lives and breeds in the same habitat Population 2. Classify the following as biotic and abiotic components. minerals, humans, rain, orchid plants, fish, worms, air, bacteria, soil, sunlight Biotic components Abiotic components Humans, orchid plants, fish, worms, bacteria Minerals, rain, air, soil, sunlight Chapter 6 Interactions Among Organisms and the Environment 97
3. The figure shows an activity to study the effect of one of the abiotic components on the distribution of woodlice. Woodlice Transparent container Wire gauze Hot water Water (room temperature) Container P Container Q (a) What abiotic component is being studied in this activity? Temperature (b) Describe the movement of the woodlice after 15 minutes. Some of the woodlice on the wire gauze above container P move to the wire gauze above container Q. (c) Give your inference based on your answer in (b). There are more woodlice on the wire gauze above container Q because woodlice like to gather in areas with lower temperatures. (d) Estimate the number of woodlice after 20 minutes in both containers. Container P: About 0–2 woodlice Container Q: About 8–10 woodlice (e) Another activity is carried out to study the effect of light on the distribution of the woodlice, as shown in the figure below. Black cloth Transparent container Woodlice Wire gauze Water (room temperature) Water (room temperature) Container R Container S (f) What would happen to the woodlice if both containers R and S are filled with water at room temperature, and container R is covered with a black cloth? Explain your prediction. The woodlice on the wire gauze above container S move to the wire gauze above container R. The woodlice are more likely to gather in dark areas. 98