ENVIRONMENTAL 5 STUDIES - I TEXTBOOK PART-2 Name: ____________________________ Section: ________________ Roll No.: ______ School: ____________________________
Preface ClassKlap partners with schools, supporting them with learning materials and processes that are all crafted to work together as an interconnected system to drive learning. ClassKlap presents the latest version of the VISA NEP series – updated and revised after considering the perceptive feedback and comments shared by our experienced reviewers and users. Designed specifically for CBSE schools, the VISA NEP series endeavours to be faithful to the spirit of the National Curriculum Framework (NCF) 2005. Furthermore, to facilitate comprehensive coverage, improved understanding of diverse themes and ease of implementation, the EVS curriculum has been split into EVS – I and EVS – II. Our books are split into two parts to manage the bag weight. They also strive to ensure inclusiveness in terms of gender and diversity in representation, catering to the heterogeneous Indian classroom. The VISA NEP EVS – I textbooks and workbooks for CBSE schools offer the following features: Interactive content that engages students through a range of open- ended questions that build curiosity and initiate exploration Opportunities for experimentation, analysis and synthesis of ideas and concepts Exposure to locally relevant environmental problem solving Effective use of visual elements to enable learning of structures, processes and phenomena A focus on subject-specific vocabulary building Integrated learning of values and life skills Promotion of participatory and contextualised learning through the engagement of all relevant stakeholders in the learning process Overall, the ClassKlap VISA NEP EVS – I textbooks, workbooks and teacher companion books aim to inculcate healthy habits, skills and values that promote environmentally sensitive and culturally responsive democratic citizenship among students. – The Authors
I Will Learn About I Remember Contains the list of learning Introduces new concepts to build on the objectives to be achieved in the prerequisite knowledge/skills required to lesson understand and apply the objective of the topic I Think Pin-up Note Introduces the concept/subtopic and arouses Contains key retention points from the curiosity among students concept Train My Brain I Understand Checks for learning to gauge the Explains the aspects in detail understanding level of students that form the basis of the concept I Apply Includes elements to ensure that students are engaged Connects the concept to throughout real-life situations by enabling students to apply what has been Be Amazed learnt through the practice questions Fascinating facts and trivia related to the concept Connect the Dots I Explore (H.O.T.S.) A multidisciplinary section that Encourages students to extend connects a particular topic to the concept learnt to advanced other subjects in order to enable application scenarios students to relate better to it A Note to Parent Inside the Lab To engage a parent in Provides for hands-on experience out-of-classroom learning of their with creating, designing and child and conduct activities implementing something given in the section to reinforce innovative and useful the learnt concepts
Contents Class 5 7 Food for Animals ��������������������������������������������������������������������������������������������������� 1 8 Food Production ���������������������������������������������������������������������������������������������������� 7 9 Forests as Shelter �������������������������������������������������������������������������������������������������� 13 Inside the Lab – B ���������������������������������������������������������������������������������������..................19 Activity B1: Seed Germination Activity B2: Food Web 10 Space Travel ��������������������������������������������������������������������������������������������������������� 22 11 Wildfire������������������������������������������������������������������������������������������������������������������� 28 12 Cyclones and Floods ������������������������������������������������������������������������������������������� 32 13 Earthquakes and Tsunami ����������������������������������������������������������������������������������� 36 14 Simple Machines�������������������������������������������������������������������������������������������������� 41 Inside the Lab – C�������������������������������������������������������������������������������������������������....... 47 Activity C1: Simple Machine Activity C2: Catapult
Lesson Food for Animals 7 I Will Learn About r herbivores, carnivores and omnivores. u body adaptations of animals to suit their eating habits. a food chain and food web. h how some animals may disappear from the Earth. I Think Saleena was eating lunch. She found a squirrel on a tree near the window. She wondered where it got its food from. Do you know how animals find food? I Remember Animals cannot make their food. So, they eat plant parts or other animals that they find in their surroundings. For example, a squirrel finds its food from the surroundings. It collects fruits and nuts from different plants. It may eat some insects too. Have you seen a squirrel collecting groundnuts a squirrel eating termites squirrels eating termites? 1
What does a cow eat? Does it eat termites like the squirrel? No. It eats grass, fruits or vegetables. Animals around us differ in their eating habits. They are of three types based on their eating habits. 1) Herbivores (‘herb’ means ‘a plant’, and ‘vore’ means ‘eat’): These are animals which eat only plant parts as their food. Cows, rabbits, deer are a few examples of herbivores. 2) Carnivores (‘carni’ means ‘flesh’, and ‘vore’ means ‘eat’): These a cow eating grass animals eat other animals as their food. For example, lion, tiger, leopard and so on. 3) Omnivores (‘omni’ means ‘all’, and ‘vore’ means ‘eat’): These animals eat both plants and animals as their food. For example, human, bear, crow, squirrel and so on. herbivores carnivores Based on the type of food omnivores they eat, animals are grouped as herbivores, I Understand carnivores and omnivores. Now, let us learn how animals find food themselves ants have a sharp from their surroundings. sense of smell If we happened to spill some sugar on the floor, within minutes, it would be surrounded by ants. How do they find it? They can smell it. If we sit outside the house or school to have some food, a crow may fly down and take away our food. 2
Birds can see things from far away. So, they notice the food on our plate even when they fly high in the sky, or sit on a tree far away from us. Animals find their food with the help of their senses. Their eagles spot their prey senses are far stronger than ours. Can we smell the sugar kept from far away in a container inside the cupboard? No. But, ants can. This strong sense of smell helps them to find their food. In the same way, birds can find food with the help of their sharp eyes. Have you seen a cat waving its ear, when we make a scratching sound on the table or ground? They have a sharp sense of hearing. This helps them to find their prey. Do you remember reading about birds and beaks and that the cats have a sharp sense shapes of beaks are suitable for the food they eat? Similarly, have of hearing you ever observed the teeth of a cow? Is it different from that of a dog? Cows have flat teeth. But dogs and cats have sharp, pointed teeth. Why are they different? It is because the food they eat is different. Cows eat grass. They need flat teeth to grind the plant parts. Dogs and cats eat flesh. They need sharp teeth to tear the flesh. A rabbit has strong front teeth. These help the rabbit to bite food a dog has sharp teeth like carrots easily. Some animals use their tongue to sense the prey as well as to catch them. For example, frogs and lizards. Snakes have many senses that help them to find their food. They sense the movement and smell of their prey. strong front teeth help a rabbit to bite a frog use its tongue to a snake use its sense of smell catch the prey and movement Food for Animals 3
Train My Brain 1) What do we call animals that eat only plants? 2) Give an example of an omnivore. I Apply What does an eagle eat? It eats small animals like rats. What do the rats eat? They eat fruits and seeds of plants. From where do these plants get their food? They make their food using sunlight, carbon dioxide, water and nutrients. In this way, plants and animals are linked to each other by eating and being eaten. This is called a food chain. A food chain Food chains are also connected to each other. For example, plants can be eaten up by a deer or a rabbit. The deer can be eaten up by not only a lion but also a tiger. The plants can be eaten up by a small bird. The small bird can be eaten up by a large bird. Such connected food chains form a food web. food web Be Amazed The largest carnivore on Earth is the South Atlantic elephant seal. It usually weighs 3,500 kg. South Atlantic elephant seal 4
I Explore (H.O.T.S.) All animals need food to live. What will happen if they do not get enough food from the surroundings? Some of them may die. Their number will decrease in that area. If the food in the surroundings became more scarce, their number will decrease further. In this way, some animals may disappear from the surface of the Earth. Many animals have disappeared from the Earth in this way. Some animals are in danger now. Only a few of their kind are left. The Asiatic lion, Bengal tiger, red panda, snow leopard are few animals whose number has decreased. Asiatic lion Bengal tiger red panda snow leopard Connect the Dots English Fun Fill in the blanks choosing the correct preposition given in the brackets. 1) A hen feeds ______________ earthworms. (in, on) 2) Grasshoppers are food______________ many birds. (for, on) Maths Fun In a food web, there are 30 food chains. All chains have an equal number of animals. If one food chain has ten animals. What is the total number of animals in the food web? Food for Animals 5
A Note to Parent There are various channels like the BBC, National Geographic Channel and Discovery Channel that shows the life of plants and animals. The TV shows on these channels also show many other adaptations of plants and animals. Watch this famous video by Planet Earth (a TV series by BBC) of a chase between a snake and an iguana for the food. https://www.youtube.com/watch?v=Rv9hn4IGofM There are many such videos. Watch them with your child to snakes chasing an show him/her the world of plants and animals. iguana 6
Lesson Food Production 8 I Will Learn About R farms. U how farmers grow food plants. A the journey of food from the farms to our homes. H growing plants without harming the environment. I Think Arvind enjoys eating mangoes, and his favourite vegetable is brinjal. What are your favourite fruits and vegetables? Have you ever thought about where these food items come from and how they reach your house? I Remember We buy fruits, vegetables, grains, pulses and so on from the market. We also buy milk, meat and fish. We know that all these food items come either from plants or animals. Where are all these plants and animals grown? Who takes care of them? Let us find out. In villages, you must have seen open fields where some plants are grown. You may have seen some people working in those fields. There may have also been some animals like goats, cows, buffaloes and so on. These are farms. A farm is a piece of land used to grow crops and raise animals. 7
People grow different types of useful plants in farms. On some farms, animals that give eggs, milk and meat are also grown. Growing useful plants and raising livestock on a farm is called farming. The people who do these activities are called farmers. farming Farmers grow useful plants and rear animals on their What are the different types of plants and animals farmers farms. All the food items we grow on their farms? buy from the market are grown by some farmers on They grow plants which give us food like vegetables, fruits, their farms. cereals, pulses, oilseeds and spices. They also grow sugar cane, tea plant, coffee plant, rubber tree and so on. The animals which are reared on farms include birds like chickens and ducks, cows, buffaloes, goats, pigs and so on. Some farmers rear fish, prawns and so on. I Understand How does a farmer grow plants on his or her farm? Let us find out. First, the farmer has to decide which crops to grow. You know that plants grow from the seeds. So, to grow plants, the farmer needs seeds of these plants. He or she may use the seeds already stored or may buy them from some other people. We have learnt that seed germination needs air, water, sunlight and nutrients from the soil. Once the seeds are ready, the farmer prepares the land to sow these seeds. The soil is cut, lifted, turned over and crushed. This is done to make sure that the soil becomes loose and airy. This will help the seeds to get more air and sunlight to germinate. 8
A plough is used to prepare the soil. The farmer may use the plough with the help of animals such as oxen and buffaloes. He or she may also use machines like a tractor to do this. Plants need nutrients from the soil to preparing the soil using animals and machines grow. So, some nutrient-rich materials are mixed with the soil. Then, the seeds are put in the soil and covered with a loose layer of soil. This is sowing. After sowing, the field is watered to help the seeds to sowing germinate. In a few days, small plantlets will grow from the seeds. The farmer waters the plants regularly. He or she will remove grass or any other unwanted plants which may also grow in the field. Fields are watered with the help of water channels made plantlets growing from seeds in the fields. A farmer may use sprinklers too. To grow some plants, the entire field needs to be flooded with water. field flooded with water field watered using sprinklers water channels in a farm Once the plants reach a certain stage of growth, some more nutrient rich materials may be added to the soil to help the plants grow. Fully grown plants give rise to flowers and fruits. Then, the useful parts of the plants are collected from them. This is called harvesting. In some plants, the fruits are harvested. In some others plants, parts like stem, leaves, flowers or seeds are harvested. Harvesting is done by people or with the help of machines. While harvesting, some unwanted plant parts may also come along. These are removed, and the plant parts are cleaned up to be used as food. Food Production 9
harvesting Train My Brain 1) Who grows plants on their farms? 2) Name a machine a farmer uses to prepare the land for sowing. I Apply The food harvested from farms need to be stored in a safe place. Otherwise, they will get spoilt. From the farms, they are carried to their storage places. These storage places are called godowns. These godowns are kept dry and airy. They are also kept free from insects and animals like rats that eat the food items. From these godowns, food is transported godowns to the main markets. From the main market, these reach the local markets. We buy this food from the local market for our use. Be Amazed Some of the first food plants to be barley wheat grown by humans were wheat and barley. Although the method used to grow them has changed, we still grow the same plants as we did around 10,000 years ago! 10
I Explore (H.O.T.S.) On farms, farmers grow so many plants. They may grow more than one set of plants in a year. They will repeat this practice year after year. If the same types of plants grow in the soil for many years, some soil nutrients may get completely used up. Some nutrients, which are not used by that type of plant, may pile up in the soil. Moreover, the farmers use some chemicals to increase the growth of plants. They also use chemicals to kill harmful plants and insects on the farm. These chemicals will kill even the useful organisms in the soil like earthworms. In these ways, farmlands may change into wastelands over the course of time. Some plants need a lot of water to grow. So growing such plants in huge numbers may lead to water shortage in that area. So, it is important to grow plants without harming the environment. How can we do that? 1) Some farmers do not use chemicals on their farms. They use plant and animal made materials to increase plant growth and reduce the harmful insects. For example, they use animal waste like cow dung, ash and plant waste like fallen leaves of trees to add nutrients to the soil. They use manure made of all these things. Farmers spray juice of the leaves of some plants such as the neem to kill insects. 2) Another practice is to grow different plants in the same field one after the other. For example, in rice fields, after the harvesting of rice, they will grow vegetables like peas, cucumbers, pumpkins and so on. This helps to keep the nutrients in the soil at a proper level. 3) I n areas where there is less water, choosing plants that need less water will be helpful. Connect the Dots Social Studies Fun Humans started farming around 10,000 years ago. India is one among those countries where farming was started. So, Indians have 10,000 years of experience in farming! Food Production 11
Maths Fun In a farm, fruit trees are planted in rows. One row has 45 trees. There are 35 rows of trees on the farm. How many trees are there in all? A Note to Parent Visit a nearby farm. Let your child see the types of work happening on a farm. Also, help them identify the plants and animals grown there. 12
Lesson Forests as Shelter 9 I Will Learn About R different types of forests. U life in the forests. A the uses of forests to living things. H the need to protect the forest cover of the Earth. I Think One day Samarth found a beautiful bird’s picture in one of the magazines his father bought for him. His dad told him that the bird could not be found in cities. It lived only in forests. Also, he promised to take him to a forest someday. Do you know what a forest is? I Remember forest with cone shaped trees When we travel to different places, we may see some lands that are covered with many trees and plants. These trees are not grown 13 by people. They just grow on their own. These are forests. Forests are lands with many trees. There are different types of forests on the Earth. For example, forests found in cold mountains have cone shaped trees with needle-like leaves. Forests which grow in warm areas with high rainfall have trees with broad leaves.
Forests which get rain throughout the year remain green always. We call them evergreen rainforests. But, in some other forests, during the autumn season, the colour of the leaves changes to yellow, orange and red and they fall off. Then, the trees grow new leaves. Forests are of different types. They look different in colour, the shape of trees, shape of the leaves and so on. evergreen rainforest forest which changes colour I Understand Have you ever visited a forest? What are the things we can find inside a forest? Let us read what Samarth found when his father took him to a forest. “Once we entered the forest, the air felt cool and fresh. We could hear the chirping of different birds and the sound of beetles. There was no proper road to walk. The guide in front of us guided us through a narrow way between the bushes. When I looked up, I could not see the sky properly. The branches beetle of trees were spread forming a cover overhead. I could find many types of birds on the trees. There was a group of monkeys on the branches of a huge tree. They were eating some berries. On one of the branches, there was a huge beehive. branches covering the sky monkeys on a tree berries beehive Suddenly I heard a rustling sound from the ground. I could see a snake crawling fast. It disappeared in the bushes. The ground was covered with leaves and animal droppings. It was spongy to walk. Using a stick, I removed some layers of leaves which covered the ground. Below them, I could find dark coloured soil. It was loose. I could find some earthworms, a snail and some other insects in it. 14
There were huge termite mounds here and there. Different types of ants and some other insects were on the ground and tree trunks. One big spider was weaving a web on a bush. Some tree trunks were covered with a spongy green growth. My mother said that they were small plants which grew only in moist places. Along with them, there were some plants with palm tree like leaves. crawling snake ground covered with leaves forest soil termite mound Many twiners were growing over the trees, and some of them were hanging from the tree branches. They were thick and strong that I could easily swing on them. There were many plants with beautiful flowers and colourful fruits. The guide told us that some of them were harmful. Then we reached a stream which flowed through the forest. The water was clean and clear. I could see the stream bed below the water. Down the stream, far away from us, there was a group of elephants. twiners with thick stems poisonous fruits forest stream elephants near the stream Then, I found a group of bats on a tree. They were sleeping, hanging upside down from the tree branches. Suddenly, a kingfisher flew down, grabbed a fish from the stream and flew away. On the other side of the stream, a woodpecker was pecking on the dried up branch of a tall tree. bats on the tree kingfisher catching a fish woodpecker on a tree Forests as Shelter 15
Far ahead of us, I found some shelters. I wondered, who lived there. The guide told us that they were the shelters of the people who lived in the forest. They ate the fruits, seeds and roots of forest plants and the flesh of wild animals. They used the water from the stream. They spoke a different language. The guide told us that we should leave the forest before it became dark. Many dangerous animals came out during the night. So we started our journey back. On the way back, mother collected some forest soil in a paper bag. She said it would help the growth of the potted tomato plants she grew in our terrace garden.” Train My Brain 1) Name one animal that Samarth found in the forest soil. 2) Which bird flew down and grabbed a fish from the stream? I Apply You read about the living things that Samarth found in the forest. Forests are home to many humans, animals and plants. They live there helping each other. What will happen to them, if we cut down trees and clear the forest? If we cut down forests, they will lose their home. Many animals will die and disappear from the Earth. Are the forests helpful only to them? Are they useful to us too? We get honey, some fruits, gums, wood and so on from forests. Forests help to absorb the rainwater into the soil. The dead leaves of trees cover the soil. The roots of plants form a network and hold the soil. So, the soil does not get washed away during rains. Moreover, they make the soil sponge-like. A sponge absorbs the water that falls on it. In the same way, forest soil absorbs and retains the water. You read that Samarth’s mother carried some forest soil to increase the growth of tomato plants. How does the forest soil increase plant growth? Forest soil is covered with layers of dead remains of plant and animal material. The tiny microbes which live in the soil help these materials to decay and mix with the soil. When these materials decay, many nutrients are released into the soil. These nutrients help the growth of plants. 16
You know that plants absorb carbon dioxide and give out oxygen. Forests have many trees. They all absorb a lot of carbon dioxide from the air and give out oxygen. This makes the air cool and fresh. Be Amazed The Sundarbans Some forests are found near the seashores. They are called mangrove forests. The Sundarbans is a mangrove forest. It is the largest mangrove forest in the world. It is located on the coast of West Bengal. I Explore (H.O.T.S.) Look at the aerial view of the Amazon rainforest. It looks like a green carpet, doesn’t it? Forests form a green cover over the land. Almost three out of ten parts of the land on the Earth is covered with forests. This forest cover of the Earth helps to control the carbon dioxide levels in the air. When the the Amazon rainforest, Brazil appears like a forest cover is reduced, the carbon dioxide green carpet in the air increases. This increase in the levels of carbon dioxide may make the air around the Earth warm. So, it is important to protect the forest cover of the Earth. Connect the Dots English Fun ‘Jungle’ is another name we use for forests. The word jungle is not English in origin. It is formed from a Sanskrit word ‘Jangala’ meaning unused land. Forests as Shelter 17
Maths Fun There is one circular lake in a forest. It has a radius of two kilometres. What will be the diameter of the lake? A Note to Parent If possible, you could plan a visit to a nearby forest with your child. Help him or her identify the differences between a forest and normal land. Encourage your child to take pictures of different forest plants and animals and make a photo album. 18
Inside the Lab – B Make sure you do these activities only with the help of a teacher or an adult. Activity B1: Seed Germination We have learnt that seeds need moisture, air and the right amount of warmth to germinate and grow. Let us do a seed germination activity to find out whether the seeds need all these to germinate or not. You will need: bean seeds (15–20 per bowl), five clean and empty beakers (one for each condition), paper towels, water to wet the towels, masking tape to label the beakers You need to: 1) keep the seeds in the following conditions: How Where beaker 1 Place the seeds on a wet paper towel. in air and light beaker 2 Place dry seeds. in air and light beaker 3 Pour water in the beaker. Put seeds in the water. in air and light beaker 4 Place the seeds on a wet paper towel. in a dark place beaker 5 Place the seeds on a wet paper towel. in a refrigerator beaker 1 beaker 2 beaker 3 beaker 4 beaker 5 in air and light dark place refrigerator 19
2) m ake predictions about what will happen. Note them down in your observation sheet. 3) h ave a look at the beakers 7 to 10 days later. Note down your results in the observation table given below. The seeds of which beaker germinate? Which do not? Note: • The seeds in the water will need to have their water changed regularly, so that mould growth does not take over. • Check once a day that the paper towel is wet. Observation table: Experiment Conditions Prediction Actual Result Actual Result number after ____ days after ____ days Activity B2: Food Web Let us create a food web using animal picture cards. You will need: • scissors • gum • chart papers • pictures of different plants or plant parts like grass, vegetables, fruits, cereals, pulses and so on 20
• pictures of animals (Example: earthworm, grasshopper, rabbit, deer, elephant, wolf, lion, tiger, eagle, frog, fish, snake, hen, crow, crane, duck, squirrel, cow, cat, dog, mouse, human being) You need to: 1) use scissors to cut the chart paper into equal sized pieces. (Take your teacher’s help while cutting.) 2) paste the pictures of animals on the chart paper pieces to make picture cards. Your game cards are ready. 3) find out how many different combinations of food chains you can form using them. For example, grass, grasshopper, frog, snake and eagle will form one chain, while plant, rabbit, wolf will be another chain and so on. 4) involve your friends too. 5) try to join the food chains to make a food web. Inside the Lab – B 21
Lesson Space Travel 10 I Will Learn About r space and spacecrafts. u astronauts, space suits and space stations. a the routine followed by astronauts in space. h how to become an astronaut. I Think On TV, Samarth saw a rocket being fired up in the sky. His father told him that it is a space mission. He wondered what a space mission is. Do you know? I Remember We know that the Earth has a layer of air around it: the atmosphere. Have you ever wondered about what is beyond the sky? Have you wondered about space beyond the Earth’s atmosphere? Beyond the atmosphere, there is an open space where there is no air. All the heavenly bodies we see in the sky are present in this space. To learn more about them, we have to travel to space. How can we travel to space and to these heavenly bodies? First, we have to travel through the Earth’s atmosphere and then through the open space beyond it. 22
We use aircrafts such as planes to travel to faraway places. Can we use these aircrafts to fly into space? We cannot. Let us see why. We have learnt that the gravity of Earth pulls everything towards it. So, all the things that we throw up fall back down. Due to this, objects need to go at a very high speed to fly straight up, cross the atmosphere and enter the space. A regular aircraft cannot fly at such a high speed. Moreover, an aircraft can fly only when there is air in the atmosphere. Its wings are pushed up by the air under it, and it needs air to burn the fuel too. The air gets thinner as we go higher up in the atmosphere. Since there is hardly any air at all in the space, an aircraft cannot fly beyond a certain height. So, to travel in space, we use special vehicles which can fly without the help of air. These special vehicles are called spacecrafts. A spacecraft can either carry human beings or cargo to space. We use high-speed rockets to take these spacecrafts out of Earth’s gravity pull. These rockets also do not need air to lift them up. A spacecraft is a vehicle used for travelling in space. A spacecraft can either carry human beings or a cargo. rocket spacecraft I Understand The spacecraft is very different from an aircraft. So, the pilots who fly planes cannot fly them. Special pilots called astronauts fly spacecrafts. Have you seen any pictures of astronauts? Indian astronauts Rakesh Sharma Sunita Williams Kalpana Chawla Space Travel 23
Look at the pictures of the astronauts. They wear special suits. Do you spacesuit know why? Space has no air to breathe. So, we will need oxygen supply. Moreover, in space, the sunlight will be very sharp and can cause sunburn. So we need to wear spacesuits that help us to breathe and protect us from the harmful sunlight. The way we have airports for aircrafts to land and take off, there are space stations for spacecrafts. Currently, the International Space Station (ISS) is the largest space station in space. It is an artificial satellite orbiting the Earth. It is made in such a way that it is suitable for living in space. The people who travel into the space alight at the space station and stay there to find out more about space. the International Space Station (ISS) Train My Brain 1) Name one space station. 2) Name any one Indian astronaut. I Apply What do the astronauts do in space? What do they eat? How do they sleep? Let us find out. Astronauts have to rely on the food they carry with them. These space food items are similar to those eaten every day on the Earth. They include frozen vegetables and desserts, refrigerated food, fruits and dairy products. The menu on the ISS includes more than 100 items. Astronauts choose their daily menus long before they fly into space. There are three meals per day. Snacks can be eaten at any time. Salt and pepper are available only in liquid form. Drinks range from coffee, tea to fruit punches. 24
space food eating in space At least two hours of a day are spent exercising. This is essential to keep fit and healthy. Astronauts spend some time on spacewalks too. Astronauts carry out some experiments and research in space. For example, the experiment to find out what will happen to the growth of plants when there is no gravity. Sleeping is a little different in space. There is no up or down. Astronauts can attach their sleeping bags to a wall or a ceiling. They can sleep anywhere as long as they do not float around and bump into something. spacewalk experiments carried out sleeping in space in space Why do astronauts travel to space and other heavenly bodies? We get to know more about the changes in the Earth’s atmosphere when we look at it from space. Space travel can help us to discover new worlds. We travel to other heavenly bodies to find whether there is life on them. Have you watched any movies that show space travel and the living things which live on other planets (aliens)? view of the Earth from space space and aliens as shown in movies Space Travel 25
Be Amazed A project named ‘Mars One’ aims to set up human colonies on the planet Mars. Mars One will begin to send one person at a time from the year 2024. Three Indians – a man and two women, have been shortlisted for the next round of selection among top 100 people! Indians shortlisted for Mars One design of human colonies for the next round on planet Mars I Explore (H.O.T.S.) We have learnt that travelling to space is different from any other travel. If you want to be one of the few people to see the Earth from space and float in a spacecraft, how do you go about it? It takes many years of study and work. To be an astronaut, we have to study and get a degree in engineering, science or mathematics. After this, we have to undergo training on flying the spacecraft, lifestyle in space and so on. We must be healthy since astronaut training can be very tiring. Astronauts from different countries may share a astronaut training mission to space. So you should be good at a common language of communication like English. Are you still interested? If so, maybe someday you can orbit the Earth in a spacecraft, walk in space or visit Mars! 26
Connect the Dots English Fun The term astronaut is formed from the Greek words ‘astron’ meaning ‘star’, and ‘nautes’ meaning ‘sailor’. Maths Fun There are 16 sunrises and 16 sunsets, every 24 hours on the ISS. How many sunrises and sunsets can astronauts see in 120 hours? A Note to Parent Discuss space, satellites and the astronauts with your child. You can show them the photographs of various space travels conducted so far, using the internet or television channels. You may also discuss the mythological stories based on space. Talk about contributions of three women scientists from ISRO in making Mangalyaan (Mars Orbiter Mission) a success. They are Seetha Somasundaram, Nandini Harinath and Minal Rohit. To know more, watch a short film named “Snapshots from Afar”. Space Travel 27
Lesson Wildfire 11 I Will Learn About R natural disasters – wildfires. u the causes of wildfires. a the effects of wildfires. h avoiding human-made wildfires. I Think Samarth was sharing his forest visit story with his friends. Then one of his friends said that on the previous day, he had seen a forest fire on TV. He also said that a lot of people died, when the fire spread to the houses of the people who lived nearby. Sherin, another friend of Samarth, said that she had seen some places getting flooded with water. Samarth wondered how forests caught fire or land got covered with water. Do you know how these disasters happen? I Remember Nature can become harmful at times. Sometimes the ground shakes or heavy rains flood the lands. Some other times, strong winds blow off everything in their way. In some places, a hot boiling liquid flows out of the Earth (lava) burning everything. Fire may break out in forest areas. 28
All these can kill humans, animals and plants and can destroy houses, roads and so on. They are disasters caused by nature. Let us learn about one of the natural disasters – wildfires. We wildfire will learn about some other natural disasters in the upcoming lessons. Wildfires are the fires which break out in the forests, grasslands and so on. In India, wildfires are very frequent. A total of 345,989 forest The disasters caused by fires were recorded across the country during 2020-2021. In nature are of different types. the state of Odisha alone, 51,968 forest fires were reported A wildfire is one such disaster. from November 2020 to June 2021, which was the highest It breaks out in forests, ever recorded during that period. grasslands and so on. Wildfires are common across the world. I Understand Now you know what a wildfire is. Do you know how it is caused? Fuel, oxygen and heat source are the three things that need to be present for a wildfire to happen. Firefighters call it a fire triangle. The dry leaves, branches and grass become the fuel. The heat of the Sun or lightning becomes the heat source. Oxygen is present in the air. Due to the extreme heat of the Sun or lightning, dry patches of grass or fire triangle leaves may catch fire. The fire may then slowly spread to nearby areas. Sparks can also be caused when dry branches rub against each other due to the wind. Sometimes wildfires are also caused by careless activities of humans. For example, people throw burning things like cigarette near the roadsides or they may not put off their camp fires before they leave. In some places, when people burn their fields, the fire may spread to nearby forest areas. campfire burning straw in the fields fire may spread from a burning cigarette stick Wildfire 29
Train My Brain 1) Name any one natural disaster. 2) Name any one thing needed to cause a wildfire. I Apply If a forest catches fire, along with all the forest products, wildlife will also be destroyed. Also, the people who live in the forest will become homeless, and they will have nothing to eat. This is a great loss. The smoke that comes out of the fire will cause air pollution. This results in breathing problems for the people who live nearby. But the fires are not always bad. The fires that break out in nature have some good effects too. In the forest areas with less rainfall, the leaves shed from the trees pile up on the ground. They do not decay as there is little moisture. Forest fires help to burn the thick layers of dried leaves and branches. When they burn, they form ash. Ash is rich in nutrients. This mixes with the soil and makes it more suitable for plant growth. So during the next rain, new plants can grow better. Uncontrolled wildfires can spread and cause a lot of damage. So, we control wildfires in many ways. We use water to control small fires. But in some places, this may not be possible. Then, helicopters are used to spray carbon dioxide, which can put out the fire. When a wildfire breaks out in a forest or grassland close to where controlling wildfire we live, we have to vacate our houses. We have to move to safer places till the fire settles down. Be Amazed Wildfires occur on every continent except Antarctica as there are no forests in Antarctica! 30
I Explore (H.O.T.S.) About nine out of ten wildfires break out due to human activities. Frequent and widespread wildfires are harmful to all living things. How can we ensure that our activities are not causing any wildfire? 1) No burning material should be thrown away. We should put out the fire. 2) After lighting a campfire, we should put it out completely before we leave the place. 3) W hile burning waste materials in fields, we should make sure that the fire does not spread to nearby areas. Connect the Dots English Fun Write two adjectives to describe a wildfire. 1) ___________________________ 2) _____________________________ Maths Fun Year Number of wildfires 2013 15 Data of wildfires in a forest is given below. 2014 6 Represent it in a bar graph. 2015 11 2016 8 A Note to Parent Discuss with your child what care we should take if we go out for camping or on a forest trail. Also, it will be a huge learning to your child if you can show him or her news reports of wildfires. Wildfire 31
Lesson Cyclones and Floods 12 I Will Learn About R cyclones. u how cyclones may cause floods. a support given to cyclone-affected people. H preparing in advance for cyclones. I Think Saif was watching TV when his father said that he needed to watch the news channel, as a cyclone alert was given by a government agency. On the news channel, they were talking about strong winds and heavy rains and showing something on a map. Saif wondered what a cyclone was. Why did the government give cyclone alerts? I Remember Let us do an activity. Take a glass of water. Add a few small sized seeds to it. Now using a spoon, stir the water. Increase the speed of stirring. What do you see in the water? In the centre, there is a depression. Around it, the water spins fast. What happens to the seeds? They are in the centre. Are they going round and round? No. They are not making any fast movements. 32
A cyclone may look like this. It has a calm centre called Cyclones are powerful spinning the eye. Around the eye, winds blow at a high speed. storms that contain strong Cyclones are formed over the ocean. They bring heavy winds and rain. They normally rains along with them. form over the oceans and move towards the land. I Understand When cyclones hit land areas, a tree uprooted by a cyclone view of a flooded area in the powerful winds destroy in Andhra Pradesh Odisha after a cyclone everything in their way. They may uproot or break the trees, blow away the roofs of buildings, displace and damage vehicles and electrical posts and so on. Cyclones push the sea water into the land. They also bring heavy rains with them. Strong rains last for hours or even days. All these lead to floods. A flood is a sudden rise in the water level making land areas submerge in water. Train My Brain 1) Where are cyclones formed? 2) What do we call the central part of a cyclone? I Apply Cyclones affect the lives of all the people living in cyclone-hit areas. Flood water may cover and wash away farms, roads, buildings and so on. It makes all the sources of water unfit for drinking or bathing. Floods may damage crops in the fields as well as stored food grains. Houses and vehicles may be damaged due to the flood waters. People may become homeless. During such disasters people need support. They need food, clean drinking water, clothes, a safe place to stay and so on. So, the government arranges rescue camps or shelters for the affected people. At the rescue camps, these cyclone-affected people are provided with food, water and clothes. Cyclones and Floods 33
Flood water may take days to drain off. temporary shelters By that time, disease-causing mosquitoes, flies and other insects may increase in number. This may lead to the spread of many diseases. Hence, medical camps are also set up to give medical support to people. Be Amazed Do you know that cyclones are given names? Some of the recent cyclones which hit India were named as Ockhi, Vardah, Hudhud, Nilam and so on. They are not named after any people. Naming helps the people to understand and remember the cyclones easily. All the messages related to a cyclone can be sent and received mentioning these names. I Explore (H.O.T.S.) It is not possible to control cyclones. But the damage to life and property can be reduced by preparing for it in advance. For this, we must know about an approaching cyclone in advance. These days, with the help of satellites, the government gives cyclone alerts 48 hours in advance. Then, cyclone warnings are given 24 hours in advance. Thus, the people can prepare in advance. When a cyclone alert or warning is satellites help to predict cyclones given, we should listen to the radio and television to get updates about the situation. 34
Connect the Dots English Fun The word ‘cyclone’ is formed from a Greek word ‘kukloma’ meaning a wheel. Can you find another word with Greek origin and its meaning? Maths Fun A flood in a small village damaged 348 houses. Write the number using Roman numerals. A Note to Parent Discuss with your child the precautions to be taken if any major disaster like a cyclone occurs. Show him or her news related to such a disaster on the television or the newspaper. Cyclones and Floods 35
Lesson Earthquakes and Tsunami 13 I Will Learn About R earthquakes. u causes of earthquakes and how a tsunami occurs. a harmful effects of earthquakes and tsunami and responses to them. h precautions against earthquakes and tsunami. I Think Pavan was holidaying with his family at a seaside resort. One day, early morning, suddenly the ground started to shake. His father asked them to get out of the room and rush towards the lawn. Pavan could not understand what was happening. Do you know what happened? I Remember Sometimes the ground shakes. It may move up and down and may crack open. This is an earthquake. An earthquake is a shaking of the Earth’s surface. It is a natural disaster. Earthquakes do not last for more than 30 seconds at a time. But, they may repeat. The strength of the quakes is different. Some of them are weak, while others are strong. 36
A device called the seismograph is used to measure the seismograph strength of the quake. Every year, a large number of earthquakes occur in different places in the world. In some places of the world, the earthquakes happen often. Most earthquakes happen along the edges of the Pacific Ocean. So, this area is called the Pacific Ring of Fire. Earthquakes are natural disasters, in which the ground shakes. They are very frequent in some places, but rare in others. Pacific Ring of Fire I Understand Why do earthquakes happen? Let us find out. Let us do an activity. Take a few cardboard pieces. Arrange them on a table close to one another. Place a few pencils, pens, erasers, sharpeners and so on over it. Now, pull two adjacent cardboard pieces slightly apart. What happens to the things you kept over it? They shake and tumble. Now, push two cardboards against each other. What happens? Their edges may bend, or one of them may slide over the other. All the things over it shake and get displaced. Earthquakes happen in a similar way. The Earth has layers. The upper layers are thin and broken into pieces. They float over the inner part. While floating, these pieces may collide or move apart. This causes earthquakes to occur. Let us do another activity. Take a thin plastic tray. Fill it with water. Lift it holding the edges. broken upper layers Now, ask another person to give a light bang on the lower part of the Earth of the tray. Observe what happens to the water. Bang a little harder. Observe the changes in the water. What do you find? Earthquakes and Tsunami 37
A bang on the tray creates ripples in the water. They start from the water ripples point where we bang and move towards the edges. Now, imagine the same situation happening in an ocean. An earthquake bangs the ocean floor. Then, waves will be formed in the ocean. They travel towards the shores. Sea shores are shallow. So, the waves do not have enough space in the water to move up and down. So, they rise like huge walls of water and lash over the coast. These huge waves are called a tsunami. Tsunami is a Japanese word meaning ‘harbour wave’. Train My Brain tsunami moving towards the shore 1) What happens when the pieces of the Earth’s upper layers collide? 2) What does the word ‘tsunami’ mean? I Apply Small earthquakes can topple a few buildings and crack roads. But, big earthquakes can destroy entire cities. Every year, around 10,000 people die due to earthquakes. Deaths happen when people are trapped under fallen buildings. The tsunami formed after an earthquake can destroy entire coastal areas. The waves may travel long distances into the land. On their way, they will sweep away buildings, vehicles, roads, trees and so on. Tsunami leads to the death of many people. tsunami waves wash off buildings and vehicles 38
In 2004, an earthquake happened in the Indian Ocean. The tsunami waves formed due to this earthquake killed 2,27,898 people. It was one of the deadliest natural disasters in the world. When an earthquake and tsunami occur, government and some other agencies help the affected people. They begin the search to find people who may be trapped under toppled buildings. They set up relief camps for rescued people to stay safely. Also, they arrange for food, drinking water and clothes for these people. Doctors are there at the camps to treat injured people. After rescuing people and ensuring they are safe, the government begins the rebuilding process. Schools, roads, hospitals, houses and so on are rebuilt, if damaged, for people to go back to a normal life. Be Amazed In 2009, an earthquake happened near the Samoan islands in the Pacific Ocean. The wave formed was just 7.6 centimetres high. But, when they reached the New Zealand coast, the height of the waves was 14 metres! I Explore (H.O.T.S.) We cannot stop or control earthquakes and tsunami. But, we can prepare for them. 1) W e can build houses that can withstand earthquakes. Tall buildings fall easily. One or two level houses are safer. We can make houses using light materials. Even if they tumble, they will not cause much harm to the people. 2) W e should not build houses near the seashore. They should be at a safe distance from the shore. 3) D uring an earthquake, if we are in a building, it is important to get out of it quickly. The building may collapse, or heavy objects may fall on us. 4) We should avoid using the lifts and other electrical equipment at such times. 5) It is important to leave everything and vacate the building as quickly as possible. 6) W hen we get a tsunami alert, we should move out of coastal areas. Earthquakes and Tsunami 39
Connect the Dots English Fun Identify the verbs, nouns and adjectives from the following words: earthquake, tsunami, tumble, lash, strong Maths Fun If 240 earthquakes happen in a month, how many earthquakes will happen in a year? A Note to Parent Keeping a safety kit ready will help us during emergencies. Help your child prepare an earthquake safety kit to be used in case of an earthquake. water prescriptions/ medicine batteries radio first aid kit important documents cell phone cash flashlight blanket map toilet paper universal tool earthquake safety kit 40
Lesson Simple Machines 14 I Will Learn About r what simple machines are. u types of simple machines. a uses of simple machines. H the simple machines in the human body. I Think Have you ever played on a see-saw with your friend? How can it lift you up and bring you down? I Remember Have you seen people loading or unloading heavy loads from a truck? How do they do it? They use a sloping surface for this purpose so that they can roll the load on it. Have you seen your dad or a using a slope to unload using a hammer to put in a nail carpenter putting a nail in the wall? What do they use? Why do they need a hammer? 41
Have you seen people drawing water from a well? They use a wheel and rope to pull it out easily. What do the carpenters use drawing water from a well using joining wooden planks together to put the wooden planks a wheel and rope together while making furniture? We see many examples in our day-to-day life where we use some simple devices that make our work easy. These are simple machines. Simple machines are the devices that make the work easier. These machines have few or no moving parts. They are used to apply force to move objects. We need less effort to move the objects because of them. They can do the work with less force. Following are the six simple machines: inclined plane, wedge, pulley, screw, lever, wheel and axle Lever, inclined plane, wheel and axle, pulley, wedge, screw are simple machines that help us in many ways. simple machines I Understand Let us now understand how these simple machines work and make things easier. 1) I nclined plane: A sloping or slanting surface makes an inclined plane. The slant of the inclined plane can move an object from one slope level to another. 2) Wedge: A wedge is a simple machine. inclined plane wedge It is used to separate any two objects by pushing them away from each other. 42
Wedge is also like an inclined plane. It has a slanting edge which is sharp. It can be used to lift things. Most of the times, it helps us in cutting something. Example: an axe used to cut wood 3) Screw: A screw is a type of inclined plane. In a screw, an inclined cutting wood using plane is twisted (swirled) around a rod like a road around the hill. a wedge (axe) Screws are useful for putting things together tightly. Example: screw is used to connect two wooden or metal blocks together screw twisted roads 4) Pulley: A pulley is a wheel with a rope around it. Pulleys make lifting objects easier. For example, cranes use pulleys to lift heavy vehicles and building materials. 5) Wheel and axle: Wheel and axle make work easier by reducing friction. A wheel helps things to move. The axle helps the wheel turn. Example: wheels of a bicycle and other vehicles axle wheel pulley crane using the pulley wheel and axle bicycle wheel with axle 6) Lever: Lever is a bar, rod or a platform that can move about a fixed point. The fixed point is called a fulcrum. Fulcrum is a point where the lever touches the support. A lever makes it easier to move a large load with little effort. Example: see-saw fulcrum lever kids playing on a see-saw Simple Machines 43
Train My Brain 1) Name any one type of simple machine. 2) Which simple machines make use of wheels? I Apply Simple machines are useful in many ways. We see them being used every day. Let us look at some examples in our day-to-day life. Inclined plane: The staircase we use to climb and the ramp used to carry loads are inclined planes. Wedge: Axe, knife and needle are a few examples of a wedge. Inclined planes Wedges staircase ramp knife axe Screw: We use so many screws in wooden furniture. The bottle caps are also a type of screw. Pulley: The rope and wheel used to draw water from a well and a crane used to lift heavy objects are a few examples of a pulley. Screws Pulleys bottle cap screws used pulley used pulley used in crane in furniture to draw water Wheel and axle Wheel and axle: Door knobs and steering wheels of the cars are a few examples of wheel and axle. door knob steering wheel 44
Lever: We use scissors to Levers cut so many things in our bottle opener house. How do you open a cold scissors stapler drink bottle? When we use a bottle opener, it takes less effort to open. The stapler we use to staple papers is a lever. Be Amazed Bicycle is a complex machine that uses simple machines like two wheels and an axle. I Explore (H.O.T.S.) bones and muscles act like levers Do you know our body parts also work as simple machines? Let us find out how. • Our teeth help us to cut with the edge; they act like a wedge. • Our knee and shoulder joints act like wheel and axle. • Our bones and muscles act like levers. The joints where the bones meet becomes the fulcrum. Muscles provide with the effort. A load is anything that we lift, push or pull. Mark the effort, fulcrum and load in the given picture. Connect the Dots Maths Fun A man lifts a 12 kg weight using his hands. He can lift 20 times more using a simple machine. How much can he lift using the simple machine? Simple Machines 45
Social Studies Fun Axes, which human beings have used since ancient times, are a type of simple machine. Probably, it was the oldest tool made out of stone by human beings. A Note to Parent Help your child to list down eight tools used in day-to-day life at home and also categorise them into the six simple machine types. Also, explain to them how simple machines help us in our work. S. No. Machine Types of simple machine Uses at home or office 1 hammer 2 lever used to put nails in the walls or wood 3 4 5 6 7 8 46
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