Living things can excrete. They need to excrete or get rid of the unwanted substances from their bodies. For example, we can excrete unwanted substances when we perspire, breathe out or pass urine. move by themselves excrete unwanted substances Living things grow reproduce respond to changes around them can Go to WB Activity 6.1 Key Ideas A Variety of Things 95 0005_Sci_TB_G2_Chp06.indd 95 5/14/2020 11:13:16 PM
Plants being watered What living things need Living things need air, food and water to stay alive. We say that these are basic needs. 6.3 Squirrel eating Duck drinking Scuba diver with oxygen tank 96 Chapter 6 0005_Sci_TB_G2_Chp06.indd 96 5/14/2020 11:13:19 PM
need Living things Key Ideas air food water What basic need is each living thing in the pictures on the previous page getting? Put on Your Thinking Cap A Variety of Things 97 0005_Sci_TB_G2_Chp06.indd 97 5/14/2020 11:13:21 PM
1. How do you classify things? 2. How are living things different from non-living things? 3. Living things can be classified into two big groups. Name these two big groups. IT’S FEEDING TIME! Process skills observing, comparing, inferring, communicating What you need some pet animals (e.g. terrapin, hamster, fish, rabbit, bird), animal food (e.g. carrots, vegetables, nuts, tubifex worms, seeds) Procedure and observations 1. Observe the behaviour of some pet animals. 2. What does each animal feed on? a) Terrapin b) Hamster Love our animals! Handle them with care. Review Questions Experiment Time! 98 Chapter 6 0005_Sci_TB_G2_Chp06.indd 98 5/14/2020 11:13:28 PM
c) Fish d) Rabbit e) Bird 3. How does each animal move? Animals How they move Terrapin Hamster Fish Rabbit Bird Conclusion What characteristics of the animals make them living things? Go to WB Revision Worksheet 6 A Variety of Things 99 0005_Sci_TB_G2_Chp06.indd 99 5/14/2020 11:13:33 PM
Name the living things in the picture. How do you put these living things into two groups? 7. Different Types of Living Things 100 Chapter 7 0005_Sci_TB_G2_Chp07.indd 100 5/15/2020 12:05:50 AM
Plants or animals? We can find storybooks, textbooks and magazines in a bookshop. Imagine that we want to buy a textbook from a bookshop. Is it easy to find the book we want? 7.1 Yes! The books in a bookshop are grouped or classified. We can go to the textbook section to select the book we want. Let’s Look at... • how to classify living things • how to classify plants • how to classify animals Different Types of Living Things 101 0005_Sci_TB_G2_Chp07.indd 101 5/15/2020 12:05:53 AM
Classifying makes it easier for us to identify and study the great variety of things around us. Let us look at how plants and animals can be classified. Animals can move freely but plants cannot. I am an animal. I can hop! I am an animal. I can fly. I am a plant. I‛m rooted. I cannot fly nor hop. 102 Chapter 7 0005_Sci_TB_G2_Chp07.indd 102 5/15/2020 12:05:59 AM
Living Things and Living Processes Living Things and Living Processes Animals are consumers. They feed on plants or other animals. I don‛t need to look for food. I can make my own! I eat insects when I get hungry. Seeds are my favourite food. Different Types of Living Things 103 0005_Sci_TB_G2_Chp07.indd 103 5/15/2020 12:06:01 AM
Plants are producers. They do not eat. They can make their own food. Living things classified as plants animals move around make food move around make food cannot can cannot can Plants do not need to move around too much. Why? Put on Your Thinking Cap Key Ideas Go to WB Activity 7.1 When there is water, light and air, I can make food. 104 Chapter 7 0005_Sci_TB_G2_Chp07.indd 104 5/15/2020 12:06:05 AM
Living Things and Living Processes Living Things and Living Processes Not all plants are alike. How are the plants in the picture the same? How are they different? 7.2 Plants Different Types of Living Things 105 0005_Sci_TB_G2_Chp07.indd 105 5/15/2020 12:06:07 AM
Some plants produce flowers. They are called flowering plants. Hibiscus Orchid tree Grass Rose 106 Chapter 7 0005_Sci_TB_G2_Chp07.indd 106 5/15/2020 12:06:14 AM
Plants which do not produce flowers are called non-flowering plants. Pine tree Staghorn fern Tree fern Juniper Different Types of Living Things 107 0005_Sci_TB_G2_Chp07.indd 107 5/15/2020 12:06:16 AM
Plants may be classified as land plants or water plants. These are some water plants. They live in the water. Water hyacinth Water lettuce Water lily 108 Chapter 7 0005_Sci_TB_G2_Chp07.indd 108 5/15/2020 12:06:21 AM
Here is another way to classify plants. Banana tree Balsam plant Papaya tree Cassia tree Tomato plant Papaya, banana and tomato plants produce fruits that can be eaten. Cassia and balsam plants produce fruits that cannot be eaten. Different Types of Living Things 109 0005_Sci_TB_G2_Chp07.indd 109 5/15/2020 12:06:29 AM
Plants whether they grow on land or in water whether their fruits can be eaten or not whether they have flowers or not classified according to Look at the fruits that can be eaten and those that cannot be eaten on page 24. How do they look different? Put on Your Thinking Cap Key Ideas 110 Chapter 7 0005_Sci_TB_G2_Chp07.indd 110 5/15/2020 12:06:32 AM
Shoot Root The seed of the bean plant grows into a young plant. The young plant develops into an adult plant. Adult bean Seed plant Germination Seedling The seeds are dispersed and the cycle starts again. Pollination and fertilisation take place. Fruit and seeds are formed. The life cycles of different plants require different lengths of time. Find out the life cycle of another type of plant. The root grows downwards while the shoot grows upwards. Life cycles of fl owering plants The life cycle of a plant refers to the stages it goes through as it develops into an adult plant. How do the stages you have learnt in the previous section come together to give the life cycle of a flowering plant? 7.3 Go to WB Activity 7.2 Different Types of Living Things 111 0005_Sci_TB_G2_Chp07.indd 111 5/15/2020 12:06:36 AM
Living Things and Living Processes Classify the animals here into different groups. Compare the way you classify them with your friends. Can you group these animals? 7.4 Animals Try This! 112 Chapter 7 0005_Sci_TB_G2_Chp07.indd 112 5/15/2020 12:06:39 AM
Different Types of Living Things They are the bird, horse, human, fish and snake. Bones give these animals their shape. We can classify animals as those which have bones inside them or those which do not have bones inside them. Can you recognise the animals shown below? Different Types of Living Things 113 0005_Sci_TB_G2_Chp07.indd 113 5/15/2020 12:06:41 AM
These animals do not have bones inside them. Place your fingers on the centre of your neck and back. You will feel your backbone. Crab Ant Beetle Sea star Butterfly Snail Try This! 114 Chapter 7 0005_Sci_TB_G2_Chp07.indd 114 5/15/2020 12:06:44 AM
We can classify animals by their body covering. Animals may be covered with feathers, scales, or fur. Our bodies are covered with feathers. Kingfisher Chicken Goose Ostrich Peacock Different Types of Living Things 115 0005_Sci_TB_G2_Chp07.indd 115 5/15/2020 12:06:46 AM
Our bodies are covered with wet and slippery scales. Our bodies are covered with fur or hair. Snake Turtle Crocodile Horse Guppy Fox Sheep Tiger Molly Our bodies are covered with dry scales. 116 Chapter 7 0005_Sci_TB_G2_Chp07.indd 116 5/15/2020 12:06:50 AM
We can classify animals as those which reproduce by laying eggs and those which reproduce by giving birth to their young. Frog Fish Turtle Chicken We reproduce by laying eggs. Different Types of Living Things 117 0005_Sci_TB_G2_Chp07.indd 117 5/15/2020 12:07:17 AM
Giraffes Human beings Rabbits Dolphins We reproduce by giving birth to live young. 118 Chapter 7 0005_Sci_TB_G2_Chp07.indd 118 5/15/2020 12:07:22 AM
We can classify animals according to the way they move. Fish These animals have fins or flippers. They can swim! Sea turtle Sharks Sea horses Penguins Different Types of Living Things 119 0005_Sci_TB_G2_Chp07.indd 119 5/15/2020 12:07:24 AM
We have legs. We can crawl or run! In which group of animals would you place yourself? Why? Eagle Beetle Butterfly Sunbird Chameleon Cheetah Turtle The animals above have wings. They can fly! Put on Your Thinking Cap 120 Chapter 7 0005_Sci_TB_G2_Chp07.indd 120 5/15/2020 12:07:27 AM
Animals classified according to whether they have bones or not type of body covering how they reproduce how they move Insects are animals that do not have bones. Each of them has: • three body parts; • three pairs of legs; and • one or two pairs of wings. WOW! Go to WB Activities 7.3 & 7.4 Key Ideas Different Types of Living Things 121 0005_Sci_TB_G2_Chp07.indd 121 5/15/2020 12:07:32 AM
1. How are plants and animals different? 2. How may plants be classified? 3. How may animals be classified? FLOWERS AND FRUITS Process skills observing, comparing, classifying, inferring, communicating What you need coloured pencils, some flowers (e.g. morning glory, hibiscus), fruits (e.g. mango, banana, guava, cassia, angsana, balsam) Procedure and observations 1. a) Observe some hibiscus and morning glory flowers. Trace out the pictures below and colour them. b) What can you say about the colours of the flowers? Review Questions Experiment Time! 122 Chapter 7 0005_Sci_TB_G2_Chp07.indd 122 5/15/2020 12:07:34 AM
Conclusion What can you infer about the following? 1. Flowers 2. Fruits 2. Observe some fruits and classify them into two groups. Edible Inedible Fruits Go to WB Revision Worksheet 7 Different Types of Living Things 123 0005_Sci_TB_G2_Chp07.indd 123 5/15/2020 12:07:38 AM
What is soil? Why do plants need soil? 8. Soil 124 Chapter 8 0005_Sci_TB_G2_Chp08.indd 124 5/14/2020 11:59:29 PM
Small stones, clay and sand at the top What is in soil? Besides light, air and water, plants also need soil to grow well. Why? Soil holds plants firmly to the ground. It also contains nutrients or ‘food’ that plants need to grow healthy. Soil consists of clay, sand, rocks and stones of different sizes. 8.1 Big and heavy rocks at the bottom Let’s Look at... • what soil is made of • the physical properties of soil in different areas • different types of soil • uses of soil Soil 125 0005_Sci_TB_G2_Chp08.indd 125 5/14/2020 11:59:30 PM
Soil also contains humus and carrion. Carrion refers to the carcass of a dead animal. Humus is formed when carrion and remains of dead plants decay. Air and water fill up the empty spaces in the soil. Soil support and nutrients for plants rocks, stones, carrion and humus provides is made up of Key Ideas Go to WB Activity 8.1 126 Chapter 8 0005_Sci_TB_G2_Chp08.indd 126 5/14/2020 11:59:39 PM
Soil found at the beach or in the desert is usually yellow. It has a coarse texture and does not hold water well. Soil samples found at different places look and feel different. 8.2 Physical properties of soil Where are these soil samples taken from? Soil 127 0005_Sci_TB_G2_Chp08.indd 127 5/14/2020 11:59:45 PM
Soil used for planting crops is usually brown. It contains a lot of humus and has a finer texture. It holds water quite well. Soil found in the wet swamps is usually grey. It has a very fine texture and holds water very well. Some water is poured over soil samples taken from the beach and from the garden. Which soil sample will stay drier? Why? Put on Your Thinking Cap 128 Chapter 8 0005_Sci_TB_G2_Chp08.indd 128 5/15/2020 12:00:01 AM
Visit a playground or a park. List the physical properties of the soil found in that area. Try This! Key Ideas such as Soil samples different areas different physical properties colour texture from have water holding capacity Soil 129 0005_Sci_TB_G2_Chp08.indd 129 5/15/2020 12:00:06 AM
Sandy soil is yellow. Its particles are large, giving it a coarse texture. The large pore spaces among the soil particles allow water to flow through easily. Pore spaces are the empty spaces between particles. Sandy soil has a poor water holding capacity and is often dry. Sandy soil Water Water flows easily through the large pore spaces in sandy soil. Pore spaces Types of soil Sandy soil is usually found in the desert and at the beach. 8.3 Desert Beach 130 Chapter 8 0005_Sci_TB_G2_Chp08.indd 130 5/15/2020 12:00:14 AM
Loamy soil is usually found in forests, gardens and parks. As water flows through the loamy soil, some of it remains in the pore spaces. Loamy soil is brown. It contains a lot of humus which provides the plants with nutrients. Its particles are smaller than those of sandy soil. Hence, it has a finer texture. The smaller pore spaces allow some water to flow through while holding back the rest of it. Loamy soil has a good water holding capacity and is often damp. Pore spaces Loamy soil Water Forest Garden Soil 131 0005_Sci_TB_G2_Chp08.indd 131 5/15/2020 12:00:23 AM
Clay soil is usually found in swamps. Clay soil is grey. Its particles are even smaller than those of loamy soil. Hence, it has the finest texture. The very small pore spaces do not allow water to flow through easily. Most of the water remains in the soil, making clay soil stay wet. Clay soil has very good water holding capacity. Swamp Water does not flow easily through the very small pore spaces. Most of it remains in the soil. Clay soil Why is loamy soil usually found in forests and gardens? Put on Your Thinking Cap Water Pore spaces 132 Chapter 8 0005_Sci_TB_G2_Chp08.indd 132 5/15/2020 12:00:27 AM
Which type of soil has very little air in it? Why? sandy soil loamy soil clay soil Soil • coarse texture • poor water holding capacity • fine texture • good water holding capacity • very fine texture • very good water holding capacity yellow is has brown is has grey is has examples Put on Your Thinking Cap Key Ideas Go to WB Activity 8.2 Soil 133 0005_Sci_TB_G2_Chp08.indd 133 5/15/2020 12:00:28 AM
Earth Processes Uses of soil Soil is very useful. It can be used in various ways according to its properties. Let us look at some of these uses. Gardening and agriculture Soil texture varies with particle size. The larger the particles, the larger the pore spaces between them. Large pore spaces allow water to flow through easily whereas small pore spaces are better able to hold water. Water drains fast through sandy soil but it collects quickly in clay soil. Hence, sandy soil is usually too dry, while clay soil is usually too wet. Loamy soil retains just enough water for most plants. Loamy soil is also fertile. It contains a lot of humus which provides the nutrients needed by plants. Loamy soil is best for gardening and agriculture. It is used to grow plants and crops. 8.4 134 Chapter 8 0005_Sci_TB_G2_Chp08.indd 134 5/15/2020 12:00:30 AM
Some plants grow well in sandy soil and some in clay soil. Surf the Internet to find out more about these plants. Building and construction Soil is an important material in the building and construction industry. Soil is used to build roads. Soil is used to build walls. Soil is commonly used as a building material for walls. A mixture of sand and clay is pressed into a frame. As the soil dries, it hardens and the frame can be removed. Clay soil is mixed with water to make mud bricks. These bricks are dried in the Sun and used to build houses. Try This! Soil 135 0005_Sci_TB_G2_Chp08.indd 135 5/15/2020 12:00:36 AM
Pottery Clay soil can be shaped. It is used in pottery to make various items. Water filters Harmful solid substances in rainwater can be removed using sand filters. As water flows through the layers of sandy soil, the harmful solid substances are trapped in the pore spaces. Shaping clay Water cleared of most harmful solids Gravel Dirty water Sand Some parts of the Great Wall of China were built with compacted soil. Parts of the wall still remain today! WOW! Go to WB Activity 8.4 136 Chapter 8 0005_Sci_TB_G2_Chp08.indd 136 5/15/2020 12:00:47 AM
This is a landfill where rubbish is dumped! Soil is used to cover the rubbish to prevent pests and bad smells from spreading. Landfills may also be filled with soil and rocks instead of rubbish. Such landfills can be used for building houses. Landfills What is shown in this picture? Surf the Internet to find out more about the landfills in your country. Going Further Soil 137 0005_Sci_TB_G2_Chp08.indd 137 5/15/2020 12:00:49 AM
Earth Processes Earth Processes used in Soil gardening and agriculture building and construction pottery water filters landfills Key Ideas 138 Chapter 8 0005_Sci_TB_G2_Chp08.indd 138 5/15/2020 12:00:50 AM
1. What is soil made up of? 2. How is soil useful to plants? 3. Name some properties that can be used to describe a soil sample. 4. Name the three types of soil. 5. If you are growing a plant that needs very little water, which type of soil should you use? Why? 6. What are the uses of soil? INVESTIGATING SOIL Process skills observing, investigating, inferring What you need magnifying glass, petri dishes, samples of beach soil, garden soil and swamp soil Procedure and observations 1. Form teams of five. You will be given three samples of soil taken from the beach, garden and swamp. 2. Observe the soil samples. Take note of their colours and feel their textures. You may use the magnifying glass to observe their textures. Review Questions Experiment Time! Soil 139 0005_Sci_TB_G2_Chp08.indd 139 5/15/2020 12:00:53 AM
3. Write your observations in a table like the one below. Soil sample Colour Texture Beach Garden Swamp Conclusion What can you infer about the soil samples taken from different places? WATER FLOW AND WATER HOLDING CAPACITY Process skills observing, predicting, investigating, inferring What you need conical flasks, filter funnels, filter paper, soil samples labelled X, Y and Z 140 Chapter 8 0005_Sci_TB_G2_Chp08.indd 140 5/15/2020 12:00:56 AM
X X Y Y Z Z 2. Observe the three soil samples and predict which one has the best water holding capacity. Give a reason for your choice. 3. Your teacher will carry out the following investigation to check your prediction. a) Set up the apparatus as shown in the diagram on the right. b) Place soil sample X in the filter funnel lined with filter paper. c) Pour 50 cm3 of water into the soil sample. Let the set-up stand for 20 minutes. Filter paper Funnel Conical flask Procedure and observations 1. Form teams of five. You will be given three soil samples X, Y and Z. Soil 141 0005_Sci_TB_G2_Chp08.indd 141 5/15/2020 12:01:01 AM
Conclusion 1. From this investigation, what can you infer about the water holding capacity of the soil samples? 2. A plant needs very little water to grow. Which soil sample is suitable for this plant? Explain your answer. Go to WB Revision Worksheet 8 d) Meanwhile, set up two more separate investigations with soil samples Y and Z. e) Measure the volume of water collected in each conical flask after 20 minutes. f) Record the results in a table. 142 Chapter 8 0005_Sci_TB_G2_Chp08.indd 142 5/15/2020 12:02:26 AM
Technology Strand Technology Strand 143 0005_Sci_TB_G2_Techno Raw.indd 143 5/14/2020 8:07:55 PM
How do we solve problems? Our brain works differently for different problems. Sometimes we understand clearly how our mind is working and sometimes we may take a longer time to figure out what is going through in our mind. One thing in common is that our thinking pattern for solving problems follows the same set of steps. There can be one particular way to solve a problem or there can be multiple ways to solve the same problem. To solve any problem, we carry out the following steps. Step 1: Identify the problem: The first step in solving a problem is to understand what the problem is. Step 2: Brainstorm the solution: Think about all the possible solutions to the problem in your mind. Step 3: Select the best idea: Out of those possible solutions, pick the best solution based on your understanding of the problem. Step 4: Try it: Try out your selected solution. Step 5: Check in: Check your solution; to see if it works. If it does not work, choose another from your possible set of solutions. Let us now apply these steps to a real life problem. Problem Solving 144 Technology Strand 0005_Sci_TB_G2_Techno Raw.indd 144 5/14/2020 8:07:56 PM