General Science Std 6 PDF - Maharashtra

 t / / / - / te / / GENERAL SCIENCE STANDARD SIX Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune. The digital textbook can be obtained through DIKSHA APP on a smartphone by using the Q....

 t / / / - / te / / GENERAL SCIENCE STANDARD SIX Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune. The digital textbook can be obtained through DIKSHA APP on a smartphone by using the Q. R. Code given on title page of the textbook and useful audio-visual teaching-learning material of the relevant lesson will be available through the Q. R. Code given in each lesson of this textbook. A First Edition : 2016 © Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune - 411 004. Third Reprint : 2019 The Maharashtra State Bureau of Textbook Production and Curriculum Research reserves all rights relating to the book. No part of this book should be reproduced without the written permission of the Director, Maharashtra State Bureau of Textbook Production and Curriculum Research, ‘Balbharati’, Senapati Bapat Marg, Pune 411004. Chief Coordinator : Coordination : Smt. Prachi Ravindra Sathe Rajiv Arun Patole Special Officer for Science Science Subject Committee : Dr Chandrashekhar Murumkar, Chairman Dr Dilip Sadashiv Jog, Member Translation : Dr Abhay Jere, Member Dr Sushma Jog Dr Sulabha Nitin Vidhate, Member Smt. Manisha Dahivelkar Smt. Mrinalini Desai, Member Scrutiny : Shri. Gajanan Suryawanshi, Member Smt. Mrinalini Desai Shri. Sudhir Yadavrao Kamble, Member Smt. Dipali Dhananjay Bhale, Member Shri. Rajiv Arun Patole, Member-Secretary Coordination : Science Study Group : Dhanavanti Hardikar Dr Prabhakar Nagnath Kshirsagar Academic Secretary for Languages Dr Shaikh Mohammed Waquioddin H. Santosh Pawar Dr Vishnu Vaze Assistant Special Officer, English Dr Ajay Digambar Mahajan Dr Gayatri Gorakhnath Choukade Shri. Prashant Panditrao Kolse Smt. Kanchan Rajendra Sorate Typesetting : Shri. Shankar Bhikan Rajput DTP Section, Textbook Bureau, Pune Smt. Manisha Rajendra Dahivelkar Paper : Shri. Dayashankar Vishnu Vaidya 70 GSM Creamwove Smt. Shweta Thakur Shri. Sukumar Navale Print Order : Shri. Hemant Achyut Lagvankar Shri. Nagesh Bhimsevak Telgote Printer : Shri. Manoj Rahangdale Shri. Mohammed Atique Abdul Shaikh Smt. Jyoti Medpilwar Smt. Dipti Chandansingh Bisht Production : Smt. Pushpalata Gawande Sachchitanand Aphale Smt. Anjali Khadke Chief Production Officer Shri. Rajesh Vamanrao Roman Rajendra Vispute Shri. Vishwas Bhave Production Officer Smt. Jyoti Damodar Karane Cover and illustrations : Publisher : Smt. Janhavi Damle-Jedhe Vivek Uttam Gosavi Shri. Suresh Gopichand Isave Controller Ms. Ashana Advani Maharashtra State Textbook Bureau, Shri. Manoj Kamble Prabhadevi, Mumbai - 400 025. B  Preface The ‘Primary Education Curriculum - 2012’ was prepared in the State of Maharashtra following the ‘Right of Children to Free and Compulsory Education Act, 2009’ and the ‘National Curriculum Framework - 2005’. This syllabus approved by the State Government is being implemented serially from the academic year 2013-2014. In the syllabus as well as in the textbooks for Std III to V, General Science is included in ‘Environmental Studies’. However, Std VI onwards, it is included separately. Accordingly, the Textbook Bureau has prepared this textbook of General Science for Std VI. We are happy to place it in your hands. Our approach while designing this textbook was that the entire teaching-learning process should be child-centred, the emphasis should be on self-learning and the process of education should become enjoyable and interesting. During the teaching- learning process, there should be clarity about the specific competencies that children are expected to achieve at the various stages of primary education. That is why, the expected competencies regarding General Science have been given in the textbook. In keeping with these competencies, the content included in the textbook has been presented in an innovative way. The content, activities and projects have been given under specific headings in each chapter to get the children to observe things carefully, to learn by actually doing something, to compile information, to classify this information or data, to draw conclusions from it, and so on. The supplementary information given in the textbook will help to make children’s learning more effective. At several places, projects have been given to help make teaching as activity-oriented as possible. The main objective of this textbook is to inculcate a scientific attitude among the children. Along with science, an introduction to the use of technology in the surroundings and an emphasis on environmental and social awareness are the important features of this textbook. This book was scrutinized by teachers, educationists, and experts from all parts of the State, to make it as flawless and useful as possible. Their comments and suggestions have been duly considered by the Science Subject Committee while finalizing the book. The Science Subject Committee and the Study Group of the Textbook Bureau and the artists have taken great pains to prepare this book. The Bureau is thankful to all of them. We hope that this book will receive a warm welcome from students, teachers and parents. Pune (Dr Sunil Magar) Date : 9 May 2016, Director Akshay Tritiya, Maharashtra State Bureau of Indian Solar Year : Textbook Production and Vaishakh 19, 1938 Curriculum Research, Pune.  For Teachers We learn many new facts while studying science. So, young children with a lot of curiosity find the subject enjoyable. However, the real objective of learning science is to learn to think about the world and all the events that take place in it, in an objective and rational manner so as to lead a happy confident life. Through the study of science we also expect children to develop social consciousness, awareness about conservation of the environment and adeptness in handling technology. We need to have adequate factual information and understanding about our world. However, in a rapidly changing world, the knowledge gained today may not suffice tomorrow. Hence, the skills required for obtaining knowledge must be learnt. These are the very skills that are learnt in the process of studying science. Many topics in science are more easily learnt by direct observation than by reading about them. Some abstract phenomena become visible through the effects they have. Hence, we do experiments related to them. They help to learn the skills of inference and verification. While learning science, these skills are learnt and internalized. This is an important objective of learning science. That we should be able to articulate what we have learnt, explain it to others, use it for further studies and finally bring about proper changes in our behavior is also an expectation from the learning of science. That is why, it is important to ensure that along with the content of the subject, these skills are also developed. Can you recall? is a section for reviewing the related topics already learnt, while the purpose of Can you tell? is introducing a topic by bringing together what the children might already know about a topic through their own reading or experience. Try this is meant to give some specific experience while Let’s try this are the parts that teachers must demonstrate to the class. Use your brain power! makes children apply the knowledge gained. Always remember... gives some important instructions or values. The sections Find out, Do you know? and Science watch are to create an awareness of the vast information that cannot be included in the textbook and to inculcate the habit of doing reference work independently. Teachers can see for themselves that this textbook is not meant for reading and explaining but for guiding students to gain knowledge by carrying out the given activities. Reading the textbook after the children have carried out the activities and discussed them in the class will make it easy and will also help to bring together and reinforce what they have already learnt. The attractive pictures will support their efforts to learn. Teachers should prepare well for discussions under Can you tell?, Use your brain power! etc. and for the various activities and experiments. They should maintain an informal atmosphere during such discussions and activities, encourage everyone to participate and make efforts to organize Science Days, presentations in the class, etc. Front Cover : Experiments included in the textbook. Back Cover : Biodiversity on the Kaas Plateau F  English General Science - Standard VI - Learning Outcomes Suggested Pedagogical Processes Learning Outcomes The learner is to be provided with The learner — opportunities in pairs/groups/ 06.72.01 Identifies materials and organisms such individually in an inclusive setup as plant fibres, flowers on the basis of and encouraged to - observable features, i.e. appearance, Explore surroundings, natural texture, function, aroma, etc. processes, phenomena using senses 06.72.02 Differentiates materials and organisms, viz. watching, touching, tasting, such as, fibre and yarn; tap and fibrous smelling, hearing. roots; electrical conductors and insulators; Pose questions and find answers on the basis of their properties, structure through reflection, discussion, and functions. designing and performing 06.72.03 Classifies materials, organisms and appropriate activities, role plays, processes based on observable properties, debates, use of ICT etc. for example, materials as soluble, Record the observations during the insoluble, transparent, translucent and activity, experiments, surveys, field opaque; changes as can be reversible and trips/visits, etc. irreversible, plants as herbs, shrubs, trees, creeper, climbers, components of habitat Analyse recorded data, interpret as biotic and abiotic; motion as rectilinear, results and draw inference/make circular, periodic etc. generalisations and share findings with peers and adults. 06.72.04 Conducts simple investigations to seek answers to queries, for example, what are Exhibit creativity presenting novel the food nutrients present in animal fodder? ideas, new designs/patterns, Can all physical changes be reversible? improvisation etc. Does a freely suspended magnet align in a Internalise, acquire and appreciate, particular direction? values such as cooperation, 06.72.05 Relates processes and phenomenon with collaboration, honest, reporting, causes, for example, diseases due to judicious use of resources, etc. deficiency of diet/deficiency diseases; Observe the Universe and different adaptations of animals and plants with facts and different events occurring their habitats, quality of air with pollutants in the universe. etc. 06.72.06 Explains processes and phenomenon for example, processing of plant fibres, movements in plants and animals, formation of shadows, reflection of light from plain mirror, variation in composition of air, preparation of vermi compost etc. 06.72.07 Measures physical quantities and expresses in SI units, for example, length. 06.72.08 Draw labelled diagrams/flow charts of organisms and processes, for example, parts of flowers, joints; filtration, water cycle, etc. 06.72.09 Constructs models using materials from surroundings and explains their working, for example, pinhole camera, periscope, electric torch, etc. G  06.72.10 Applies learning to scientific concepts in day to day life, for example, selecting food items for a balanced diet, separating materials, selecting season appropriate fabrics, using compass needle for finding directions, suggesting ways to cope with heavy rain/drought etc. 06.72.11 Makes efforts to protect environment, for example, minimising wastage of food, uses of water, uses of electricity, and generation of waste, spreading awareness to adopt rain water harvesting, care for plants (plantation) etc. 06.72.12 Exhibits creativity in designing, making use of available resources, planning etc. 06.72.13 Exhibits values of honesty, objectivity, cooperation, freedom from fear and prejudices. 06.72.14 Comparative study of star, planet, satellite, Asteroid by observing them in the Universe. 06.72.15 Collect information of different concepts, processes by using internet and different ICT technology. CONTENTS No. Chapters Page No. 1. Natural Resources – Air, Water and Land............................................ 1 2. The Living World................................................................................... 9 3. Diversity in Living Things and their Classification............................ 18 4. Disaster Management.......................................................................... 26 5. Substances in the Surroundings – Their States and Properties............. 32 6. Substances in Daily Use...................................................................... 42 7. Nutrition and Diet................................................................................ 50 8. Our Skeletal System and the Skin....................................................... 57 9. Motion and Types of Motion.............................................................. 65 10. Force and Types of Force..................................................................... 70 11. Work and Energy................................................................................. 76 12. Simple Machines.................................................................................. 84 13. Sound................................................................................................... 91 14. Light and the Formation of Shadows................................................... 97 15. Fun with Magnets.............................................................................. 105 16. The Universe...................................................................................... 112 H  1. Natural Resources – Air, Water and Land Atmosphere Observe. Observe the picture alongside and answer the questions. 1. Where do we see the birds ? 2. Where is the cow grazing ? 3. Locate the trees and the road. 4. Where does the river come from ? How does it flow ? Hydrosphere 5. Where is the aeroplane ? 6. Where are the fish seen ? Lithosphere 7. On what is the sailboat floating ? Natural resources 1.1 : Spheres of the earth You can see that some things in the picture are in water, some on land, and some in the sky, that is, Air, water and land are in the air. Thus, all things on the earth are associated the factors important with air, water and land. Air, water and land are for sustaining the living called the earth’s atmosphere, hydrosphere and world on the earth lithosphere, respectively. Moreover, different living and for fulfilling their basic things occupy these three spheres of the earth. needs. They are called These living things and the parts of the lithosphere, natural resources. hydrosphere and atmosphere which they occupy are together called the biosphere. These spheres have formed on the earth naturally. We have learnt all this in the previous standards. The atmosphere is the layer of air that surrounds the earth. The surface of the earth comprises water and land, that is, the hydrosphere and lithosphere. Of these, the hydrosphere occupies a much larger part than the lithosphere. Figure 1.2 shows the proportion Land 29% of land and water on the earth’s surface. We also look upon these natural components in Water 71% solid, liquid and gaseous form as resources. In other words, we use them to fulfil our requirements. Let us now study all these three components in detail. 1.2 : Proportion of land and water 1  Can you recall ? What are the five layers of the atmosphere ? Air The air in the atmosphere around the earth contains nitrogen, oxygen, carbon dioxide, six inert gases, nitrogen dioxide, sulphur dioxide, water vapour and dust particles. The troposphere contains about 80% of the total mass of gases in the air, while this proportion is about 19% in the stratosphere. Further, in the mesosphere and ionosphere, the proportion of the mass of gases goes on decreasing. Gases are not found in the exosphere and beyond. You can see that air is a mixture of Other constituents several gases and is the chief constituent of air 0.07% of the earth’s atmosphere. Besides these Carbon dioxide gases, air also contains water vapour Argon 0.9% 0.03% and dust particles. The amount of the Oxygen 21% gases in the air is the greatest near the surface and decreases as we go higher and higher from the surface. That is, air becomes rarer at higher altitudes. Nitrogen 78% The proportions of the constituents of air and some of their uses are given here. 1.3 : Proportions of the various gases in the air Some uses of gases in air Nitrogen – Helps living things Argon – Used in electric bulbs. to build the necessary proteins. Helium – Used for obtaining low It is useful in the production of temperature and also for generating ammonia and in airtight packaging lift in airships. of foodstuffs. Neon – Used in decorative lights Oxygen – Necessary for respiration and for street lighting. in living things and for combustion. Krypton – Used in fluorescent Carbon dioxide – Plants use it for tubes. producing their food. Used in fire Xenon – Used in flash photography. extinguishers. Always remember... The living world on the earth is sustained due to the balance between various gases and other constituents of air. The atmosphere is a very important filter. It allows the light and heat of the sun to reach the earth, which is necessary for life. But it prevents the harmful elements from reaching the earth. It is in the atmosphere that fog, clouds, snow and rain are produced. 2  Observe and discuss. What is the similarity in the three pictures below ? 1.4 : Air pollution All the above pictures show large scale emission Harmful substances of smoke through different agencies. This smoke released in air through directly mixes with the atmosphere, disturbing the combustion of fuels balance between the constituents of air. This is called l Nitrogen dioxide air pollution. Harmful gases are given out through combustion of fuels in vehicles and in big industries l Carbon dioxide and also through incomplete combustion of fuels like l Carbon monoxide wood and coal. As a result, air pollution is increasing l Sulphur dioxide day by day. l Soot Ozone layer – the protective shell There is a layer of ozone (O3) gas in Do you know ? the lower part of stratosphere. Ozone gas is not directly useful for the survival of living In metropolitan cities like Mumbai, things, yet it is very important for living Pune or Nagpur boards are displayed things to have this layer of ozone at a high at places of heavy traffic to show altitude around the earth. The ultra violet the proportions of the various rays coming from the sun are very harmful constituents of the air at that place. for living things. The ozone gas absorbs these Due to these boards, we can see the rays. As a result, life on earth is protected. amount of harmful elements in the air. The ozone layer is destroyed if chemical gases like carbon tetrachloride or the chlorofluorocarbons used in air conditioners and refrigerators mix with the air. The 16th of September is celebrated as ‘Ozone Protection Day’ all over the world to make everyone aware of the importance of ozone. Use your brain power ! What would have happened if there were no air on the earth ? 3 Water Purpose for which Amount of water is used Water (approx.) in litres Try this. - Bath Observe how much water is used and - Brushing teeth for what purposes it is used in your house - Washing clothes for a whole day. Record it in a chart like and utensils the one shown here. Discuss this data in the class. Divide the total amount of - Mopping the floor water used in your house by the number - Drinking of persons to find out how much water - Cooking each person needs. Total use of water You will see that it is almost impossible for us to spend even a single In nature, water occurs in three day without water. We need to drink three states. Water does not have colour, to four litres of water every day so that all our bodily functions run smoothly. Other taste or odour. Many substances readily living things also require water although dissolve in water. Therefore, water is a the amount of water they need may vary universal solvent. according to the size of their body. Thus, The blood of animals and the sap we see that water is very important. in plants contain a very high proportion If hydrogen gas burns in air, it of water. No living thing can survive combines with oxygen and water is without water. Therefore it is said that formed. We have learnt about some ‘Water is life.’ characteristics of water in the previous standards. Water available on earth Percentage Seas, Oceans 97% Observe and discuss. 2.7% Groundwater, ice, Water available and water for drinking Sales Water available for in other forms drinking (fresh water) Total 100% 1st Qtr Seas and Oceans 2nd Qtr 3rd Qtr We cannot use all the water on earth because seawater is salty. Some water is in the frozen state. A very small quantity of water is available for drinking. Yet it 1.5 : Distribution of water on the earth is enough for all living things. Find out. In what ways is the water in seas and oceans useful even though it is salty ? 4  Observe and discuss. For which purposes is water being used ? Do other living things use water like we do ? We use water in large quantities. We have learnt that water on the earth is regulated through the water cycle. The water vapour formed from oceans is the main source of water in the water cycle. It gets converted into rain, creating fresh water sources on earth. 1.6 : Uses of water on the earth We get water from natural sources Always remember... such as streams, rivers, ponds, springs and lakes. Man also digs wells and borewells to lift ground water. Apart from this, man 1. Use water sparingly. has also constructed bunds and dams of 2. Block water, let it percolate. various sizes on rivers. 3 Store water wherever possible. Due to the uncontrolled use of water 4. Reuse water wherever possible. for an increasing population, industry and Remember, stored water does not farming, it is now in short supply. Water become stale at once. scarcity has become a serious problem. l What is land made of ? l Is land flat everywhere ? Can you tell ? l What do you see on land ? l Does man produce soil/land ? l What has man created on land ? l If a deep pit is dug in the ground, what do you find there? Land Land is seen in the form of stones, soil, big rocks. It is not flat everywhere. It is hilly in some places and flat in others. All terrestrial animals including man live on land. Some terrestrials dig burrows in the ground for shelter. This means that they use land for fulfilling their need. We also use land for farming and for building houses and roads. We make use of plants and animals in the forests that grow on land. The minerals, crude oil and natural gas obtained from the earth (land) are very important for us. It means that land is an important resource. Let us see exactly what land is made of. 5  1. Take a transparent plastic bottle, a Let’s try this. handful of soil, some stones, sand, some dry leaves and water. 2. Cut off the upper tapering part of bottle. Dry leaves Put the rest of the materials in the lower Soil part and add water. 3. Stir the mixture thoroughly and put it aside. Sand Observe it the next day and answer. Small stones l How does the mixture in the bottle look Big stones now ? l Do you see layers in it ? 1.7 : Layers of the mixture in the bottle l What is seen in the different layers from The land on earth also looks like this. If a top to bottom? pipeline is being laid in your neighbourhood, observe carefully the pits dug for this purpose. You will see some layers under the land surface, as shown in the accompanying figure. Humus If the land has mature soil, the topmost Soil layer is formed by the decomposition of the remains of plants and animals. This layer is Immature called ‘humus’. It is usually found in dense soil forests. The land below this is full of sand, soil, small stones, worms, and insects. Soil and pieces of bedrock are found below this Layer of layer of land. This soil is immature. Further soil and below this layer the proportion of soil small rocks decreases and that of rock increases. This is the layer of bedrock. The main minerals in the soil are derived from these rocks. That is why, soil in different regions is different. The Bedrock colour and texture of soil are both determined by the bedrock. 1.8 : Layers of land The process of soil formation The soil on the land is formed by a natural process. The abiotic components of soil are supplied through the weathering of the bedrock. Due to the heat, cold and water of the sun, wind and rain respectively, the bedrock breaks down into pieces. Stones, sand and soil are formed from these pieces. Microbes, worms and insects are found among them. Rodents like mice and rats are also found here. The roots of trees growing on the land also help weathering of rocks. The process of soil formation is slow and continuous. It takes about a thousand years for a 2.5 cm thick layer of mature soil to form. 6  Soil can get destroyed in a short period due to floods, storms and human activities such as mining. That is why, it is necessary to conserve soil and to prevent erosion of land. The best remedy for this is to increase the green cover of the land. Erosion of land is reduced if grass, trees and bushes are grown in it. Obtain specimens of soil from various places in your surroundings Try this. such as your own yard, a garden, hills, river banks, fields and rocky ground. Note the differences in the specimens with respect to colour, feel, texture and the size of the particles. Do you know ? Use your brain power ! Humus is the layer formed on soil due to the decomposition of dead plants and animals What are the constituents of soil ? by microbes. Humus supplies nutrients Classify them as biotic and abiotic to the soil. Humus is also important for constituents. aerating the soil and for holding water in the soil. The proportion of humus in the upper layer of good fertile soil is about 33% to 50%. Forests on land got buried underground due to the great upheavals that took place on the earth many ages ago. After that, the process of formation of fossil fuels from the remains of living things took place underground. We get fuels like petrol, diesel, kerosene, paraffin and other useful materials like tar and wax from the fossil fuel called crude oil. Living things use land, water and air available on earth and so does man. However, Institutes at work the portions of these resources that are actually India Meteorological put to use are very small as compared to the Department (IMD) was whole earth. Look at the following table. established in 1875 for studying 29% the weather in the Indian Land subcontinent. The main function Potable water / fresh water 0.3% of this institute is to observe the Oxygen 21% weather and to make weather Even in these small proportions, the forecasts. This institute also resources shown in the above table are conducts research related to sufficient for all living things. Only, it is very changes in weather, makes necessary for man to control his greed. In other forecasts about rains and studies words, he must use these resources judiciously, the developments related to with the awareness that they are meant for all global warming. other living things and not just for mankind. 7  What we have learnt- l There are many constituents of air such l The elements available in nature as nitrogen, oxygen, carbon dioxide, which fulfil the basic needs of living inert gases, water vapour and dust things are called natural resources. particles. l Air, water and land are important l The ozone layer is a protective shell of natural resources. the earth. l Soil has both biotic and abiotic l Natural resources should be used constituents. carefully and sparingly. Exercise 1. Fill in the blanks. 5. Name the following. (a) The layer of ozone gas absorbs (a) Constituents of the biosphere ………… rays that come from the (b) Biotic constituents of soil sun to the earth. (c) Fossil fuel (b) Of the total water available on (d) Inert gases in air the earth, fresh water forms...... (e) Gases that are harmful to percent. the ozone layer (c) Both...…. and ……... constituents 6. True or false ? are present in the soil. (a) Land and soil are the same thing. 2. Why is it said that – ? (b) The water in a lake is called ground (a) The ozone layer is a protective water. shell of the earth. (c) It takes about 1000 years to form a (b) Water is life. 25 cm thick layer of soil. (c) Seawater is useful even though it is (d) Radon is used in decorative lights. not potable. 7. Answer in your own words. 3. What will happen if – (a) Explain with the help of a diagram (a) Microbes in the soil get destroyed. how soil is formed. (b) The number of vehicles and (b) Why is there a shortage of water factories in your surroundings even though it occupies about 71% increases. of the earth’s surface ? (c) The total supply of potable water is (c) What are the various constituents of finished. air ? Write their uses. 4. Match the following. (d) Why are air, water and land Group ‘A’ Group ‘B’ considered to be valuable natural (1) Carbon (a) Generation of resources ? dioxide soil Activity : (2) Oxygen (b) Rain l Obtain detailed information about (3) Water (c) Plants and the work of the India Meteorological vapour food production Department. (4) Microbes (d) Combustion l Find a remedy for water scarcity. lll 8  2. The Living World List the things seen in the picture. Say whether they are Can you recall ? living or non-living things. Characteristics of living things There are many kinds of plants and animals around us. They show some similarities and some differences. Yet, with the help of certain features, we can tell that they are all living things. These features are not seen in non-living things. Such features are said to be the characteristics of living things. Let us study these characteristics. 2.1 : Various things in our environment What differences do we see between the young ones and the Can you tell ? adults in the picture ? Growth 2.2 : Growth in living things A baby grows up to become an adult person - woman or man. During the period of its growth, the baby gains in height, weight and strength. In the same manner, all animals grow into adults in a certain period. Generally, humans require 18 to 21 years for this growth. Find out how long it takes for the young ones of hens, cows and dogs to grow into adults. 9  Stretched Loose thread thread Try this. Tie a thread to the tip of a potted sapling. Keep the thread stretched and tie it to a peg or nail above the plant. What do you observe after ten to fifteen days ? What tells us that the plant has grown taller ? In all plants, it is mainly the width and height of the stem that grows. As they grow, some plants develop branches while others do not. Though all living things grow, animals grow only for a certain period. Plants, on the other 2.3 : Sapling in a pot hand, grow as long as they live. The growth of living things occurs from within the body, which means that growth occurs in all parts of the body. 2.4 : Growth in banyan and coconut trees Use your brain power ! What differences do you see in the growth of trees like the mango, banyan and peepal and that of the bamboo, coconut and toddy palms. Food is necessary for growth Sunlight Plants make their own food in sunlight. Plants produce food from Oxygen water, nutrients in the soil and the carbon dioxide present in the air. This process takes place in the leaves of plants. It is brought about Carbon in the presence of sunlight, with the dioxide help of the chlorophyll in the leaves. This process of food production is called photosynthesis. During this process, plants give out oxygen. Water and Plants appear mainly green in nutrients colour due to the chlorophyll in them. 2.5 : Photosynthesis 10  2.6 : Intake of food by animals Animals, however, do not have chlorophyll. The intake of food and They do not produce their own food. They search the resultant growth is an for food. Animals such as goats, sheep, horses eat important characteristic of grass while wild animals such as tigers and lions living things. meet their need for food by hunting other animals which live on plants. Respiration Observe and discuss. 1. Hold your hand in front of your nose or keep your hand on your chest. What do you feel ? 2. If we observe a sleeping dog, what movement of its belly do we see ? Living things need oxygen in order to live. Inhaling oxygen and exhaling the A leaf of a plant carbon dioxide formed in the body due to the use of oxygen is called respiration. Animals such as fish, snake, mouse, etc. have specific organs for respiration. On the other hand, plants respire by means Nose of microscopic pores on their stems and leaves. Gills Respiration is a characteristic of 2.7 : Respiration in living things living things. Can you recall ? 1. Is all the food we eat used by the body ? 2. What is the unused part of food converted into ? Excretion Waste substances are formed during the many processes that take place in the bodies of animals. These are called excreta and the process of eliminating them from the body is called excretion. Animals have specific organs for excretion. Plants, too, excrete. For example, some plants shed leaves in a specific season. Waste substances stored in the leaves of plants are shed along with the leaves. 2.8 : A tree shedding leaves 11  Try this. Take a transparent plastic bag. Tie it over a leaf of a plant as shown in the picture. Observe it after six to seven hours. What do you see ? Droplets of water collect on the inside of the bag. It means that, plants excrete water in the form of vapour. Excretion is a characteristic of living things. Use your brain power ! What is the sticky substance seen on the stems of the babul (acacia) or drumstick trees ? 2.9 : Excretion on the leaves of a plant Observe and discuss. Have you experienced this ? What happened immediately after the following actions ? 1. Light flashed suddenly into your eyes. 2. Suddenly you felt a pinprick. The mimosa 3. The leaves of the mimosa plant were touched. 4. At sunset, lamps on the street or courtyard are lit and insects gather around the lamps. Responsiveness to stimuli and movement Living things act in various ways when responding to a stimulus. If you suddenly enter a cowshed, the cows and buffalos stand up, begin to move, one or two may even start mooing. These are all movements. A potted plant A creeper planted in the courtyard leans towards 2.10 : Responsiveness and movement a support. A potted plant placed in a window grows towards sunlight. It means that plants, too, show movement. Living things move of their own accord. Use your brain power ! The movement or the change taking place in 1. In each of the examples a living thing at such a time is their response to a given above, what is the stimulus. An event that occurs in our surroundings is stimulus and what is the a stimulus. The ability of living things to respond to response ? a stimulus is called their responsiveness to stimuli. 2. What is the main difference Responsiveness to stimuli between the movements of is a characteristic of living things. plants and animals ? 12  Can you tell ? What do we learn from these pictures ? Reproduction Living things produce other living things like themselves. Some animals give birth to their young ones. Some lay eggs. Their young ones hatch out of the eggs. New plants are produced A bird and its eggs Bryophyllum from the seeds, stems or leaves of plants. The process by which a living thing generates a new living thing like itself is called reproduction or procreation. Reproduction is a characteristic of living things. A mare and her foal Rose cuttings Use your brain power ! 2.11 : Reproduction Why have so many types of plants and animals been able to survive on the earth even today ? Observe and discuss. A definite lifespan 2.12 : Lifespan At a certain stage of life, living things become capable of reproduction. Later on in life reproduction stage, their organs become weak and still later, their life comes to an end. In other words, living things die. The lifespans of different animals and plants are different. For example, the lifespan of the dog is about 12 to 18 years, while the ostrich lives for 50 years. You may have wondered what exactly the living things are, how they came into being, and so on. 13  Do you know ? The lifespan of the giant turtle found on the Galapagos Island in South America is about 170 years. On the other hand, the lifespan of the mayfly ranges from 1 hour to 24 hours. Observe a honeycomb and a wall. Can you tell ? What are they made of ? You may have seen the small compartments of a honeycomb. These compartments are joined together to form a honeycomb. A wall has bricks. To construct a wall, we firmly join the bricks together. 2.13 : A wall A honeycomb A cellular structure Living things are made of small units called cells. All the actions and processes in the bodies of living things are brought Amoeba about with the help of these microscopic cells. Some living things are made of a single cell. These are called unicellular organisms. On the other hand, the living things that Paramoecium are made of many cells are called multicellular organisms. The amoeba and some other microorganisms are unicellular while man, cow, mouse, cockroach, elephants, banyan tree, the onion plant, etc. are all multicellular organisms. All the characteristics of living things are seen in every cell of a living thing, whether it is unicellular or multicellular. Cellular structure is the main characteristic of living things, even though the number of cells may vary. 2.14 : Various living things 14 What they do ? Institutes at work The The institutes Botanicalthat workoffor survey the (1890) India survey and and the conservation ZoologicalofSurvey the various plants of India (1916) areand theanimals in responsible institutes different parts for of theIndia areand survey the conservation Botanical Survey of India (1890) of, respectively, plants and the and animals in Zoological the variousSurvey parts of India India.(1916) In caserespectively. you find anIn case you plant unfamiliar or animalfind an unfamiliar in our surroundingsplant youorcananimal in your surroundings, communicate you can to obtain with these institutes communicate information about it.. with these institutes to obtain more information about it. Can you tell ? In what way are plants and animals useful to us ? Useful living things Plants are used for household as well as industrial purposes. For example, fenugreek (methi), potato, okra (bhendi), apple, banana are used as food while Vasaka vasaka (adulsa), hirada, behada, asparagus are used as medicines. Animals are also useful to us. Dogs, cats, cows, buffalos are kept for domestic uses. Fish, sheep, fowl are used as food, while animals like horses, oxen, camel 2.15 : Useful living things prove useful in various occupations. The earthworm is very useful in agriculture. Harmful living things Some animals and plants around us are harmful to man. For example, mosquitoes and flies spread diseases. Cockroaches, mice, rats destroy our food. Lice, ticks also spread diseases. The bites of some poisonous lizards, spiders, snakes and scorpions can even cause death. If wild elephants enter human settlements, they cause a lot of destruction. Some plants, too, can be harmful, as for example, the dodder, parthenium and other weeds. Pods of the nettle, colocasia leaves cause itching. Plants like oleander, lantana have strong odours. The datura plant is poisonous. Uncontrolled growth of fungi and algae in water pollutes drinking water and may cause the spread of diseases. Datura Colocasia leaves 2.16 : Harmful living things 15 Wild animals Wild animals that hunt other animals for food are called predators, for example, tigers, lions, wolves, leopards. Sometimes, due to deforestation, such animals enter human settlements in search of food and may kill domestic animals or people. Find out. Watch TV channels such as National Geographic, Discovery and collect information regarding various plants and animals found in our surroundings. Have a class discussion with reference to the collected information. 2.17 : Wild animals Always remember... Many plants and animals in nature satisfy our needs. The use of such plants and animals should be restricted only to our needs. We should not pluck leaves, flowers and fruit unnecessarily. Animals should not be hunted. They should not be teased just for fun. It is the responsibility and duty of all of us to protect plants and animals. What we have learnt- l Growth, respiration, excretion, reproduction, responsiveness to stimuli, movement, a definite lifespan and a cellular structure are the characteristics of living things. l Animals grow for certain period of their life. Plants, however, grow as long as they live. l Animals have specific organs for respiration, while plants respire through microscopic pores on their leaves and stems. l The process of eliminating waste products from the body is called excretion. l All living things have the ability to reproduce. l Living things move because of their ability to respond to stimuli. l Plants show spontaneous movements but they cannot leave their place and go elsewhere as animals do. l Living things have a definite lifespan at the end of which they die. l Many animals and plants are useful to us in our daily life. Some animals and plants can be harmful to us. l The smallest unit of a living thing is the cell. 16  Exercise 1. Write the answers to the following 4. Write the uses of these animals and questions in your own words. plants. (a) What are the differences between Animals : Honeybees, sharks, yaks, plants and animals ? sheep, earthworms, dogs, bivalves, (b) What are the similarities between horses, mice. plants and animals ? Plants : Ginger, mango, eucalyptus, (c) How is the plant kingdom useful to babul (acacia), teak, spinach, aloevera, us ? turmeric, holy basil, karanja, moh, mulberry, grapevine. (d) How is the animal kingdom useful to us ? 5. What are the peculiarities of the (e) What makes living things different movements of these living things ? from non-living things ? Living things : Snakes, tortoises, kangaroos, eagles, chameleons, 2. What helps them to breathe ? frogs, gulmohur, sweet potato (a) A fish (b) A snake creeper, dolphins, ants, rattlesnakes, (c) A crane (d) An earthworm grasshoppers, earthworms. (e) Man (f) A banyan tree 6. Write in detail about how the (g) A caterpillar plants and animals found in your 3. Fill in the blanks with the proper surroundings prove useful or words from the brackets. harmful. (a) The process by which plants make Activity : their own food is called............. l Obtain information about the (b) To inhale ……… and to exhale work of the Botanical Survey of...….. is called respiration. India and the Zoological Survey (c) The elimination of waste of India by visiting the websites : substances from the body is called www.bsi.gov.in www.zsi.gov.in..…........ l Collect information about the (d) The ability to respond to an event lifespan of various animals, make is called ….. to ……. a chart and display it in your class. (e) On completing their lifespan, every l Gather information about the living thing ……... poisonous snakes found in India and (oxygen, dies, excretion, present it in a Science Exhibition. carbon dioxide, responsiveness, photosynthesis, stimuli) lll 17  3. Diversity in Living Things and their Classification Can you recall ? In which spheres of the earth do living things exist ? The geographical conditions at different places on the earth are very different. We find that living things exist in all these diverse conditions. When we live in a certain place, we adjust to the conditions there. Various types of living things have survived because of their ability to adjust themselves to the conditions in their surroundings. Can you tell ? Are the plants and animals that you have seen all alike ? Diversity in plants Various types of plants are found in many places around us. Some plants like grass are short, while others are tall and have a canopy. Some plants grow underwater, while some others float on water. We find that some plants grow even in deserts. Moreover, we find that there is a lot of variety in the same type of plant. For example, there are different varieties of rice or wheat, different types of roses, and mangoes of different flavours. Some plants grow even without stems, leaves or roots. These are very different from ordinary plants. Let us study this diversity among plants. Plants make their own food in sunlight. Such plants are called autotrophic plants. For example, the hibiscus, pomegranate, periwinkle, etc. Some plants like funguses, loranthus, dodder use other plants for food and are said to be heterotrophic. Plants like the pitcher plant even consume insects. They are insectivorous. 3.1 : Method of nutrition in plants 18  The structure of a plant Plant structure can generally be divided into two parts - the stem which grows above the ground and the root which grows below the ground surface. The root, stem and leaves are the main parts of plants. From time to time, plants bear flowers for reproduction. Flowers are transformed into fruits. Fruits have seeds. Seeds give rise to new plants. The flower : This The leaf : The is the most attractive leaf is flat. It plays an part of a plant. It is important role in the connected to the stem production of food. by a stalk which may be Leaves are mainly of long or short. A flower two types : simple and has a typical colour and compound leaves. shape. The flower is an important means of reproduction. The stem : The height, shape and size of Simple leaf Compound leaf a plant depends upon the (Ex. Hibiscus) (Ex. Rose) stem. The stem carries out the functions of production, conduction The fruit : Fruits and storage of food. In have different shapes. some plants, it has the Fruits contain one or function of reproduction. more seeds. The pods It gives support to other of beans and peas are parts of the plant. 3.2 : The structure of a plant actually fruits. The root : Roots hold the soil firmly and anchor the plant. The main functions of the root are to absorb and transport water and nutrients from the soil. The roots of the carrot and radish also store food. There are two types of roots : taproot and fibrous root. Taproot Fibrous root (Hibiscus, Banyan) (Onion, Grass) Need for classification of plants Up to now, information about lakhs of plants has been collected. While studying the diversity in plants, they are classified for the sake of convenience on the basis of the similarities and differences in their structure, their organs and their other characteristics. 19  The scientist Carolus Linnaeus made the first scientific classification of plants. Initially, it was his method of classification that was used by all. Take a round through a garden or in your surroundings Observe and discuss. and list the plants that you see. Draw their pictures as well. Draw a table as shown below and complete it on the basis of the information you gather. Discuss it in the class. Name Where Nature of the Height Branches Leaves Flowers Nature of Uses of the does stem (Short, (Nature, (Colour, (Colour, the fruit (Which plant the (Circumference, medium, number, shape, fragrance, (Colour, part is plant colour, bark, very tall, etc.) edge, shape, etc.) shape, used.) occur/ hard/soft, etc.) etc.) etc.) hardness grow or softness, etc.) Rose Classification of plants We can easily notice the differences in the shape and height of the plants in our surroundings. It is easy to classify the plants on the basis of this observation. 3.3 : Diversity in plants Can you tell ? 1. What are the similarities between a mango, a banyan and a tamarind tree ? Trees : Some plants grow tall. Their stem, or trunk, is hard and strong. They have branches at some height above the ground. They bear flowers and fruit for many years. Such plants are called trees. Trees are tall, big and perennial, i.e., they live for many years. 20 2. What are the similarities between the hibiscus, oleander and lantana plants ? Shrubs : Some plants grow close to the ground. They give out branches very close to the ground. They are shorter and smaller than trees, but they have a thick and hard stem. The oleander, hibiscus, lantana, koranti and rose are shrubs that may grow up to two to three metres. 3. What are the similarities between the fenugreek and periwinkle plants ? Herbs : Herbs grow 1 to 1.5 metres tall. The stems of herbs are green and quite flexible as compared to those of trees and bushes. Herbs may live for a few months or up to two years. According to the size and height of their stems, plants can be classified into three types : trees, shrubs and herbs. Have you seen vines like the pumpkin, the railroad creeper, Can you tell ? kavali, watermelon or the grapevine ? How do they grow ? Vines : Some vines need vertical support for growing, while some others spread on the ground. Climbers like the money plant have aerial roots. Have you seen the cucumber tendrils that look like a spring ? Of what use could they be ? Touch the stem of any vines. What do you feel ? The stem of a creeper is very flexible, soft and green. It grows rapidly with the help of a support. 3.4 : Various creepers and climbers Can you tell ? For how many years do crops like bajra, wheat, corn, radish, marigold live ? The lifecycle of plants like jowar, sunflower is completed in one year. These plants are called annuals. The lifecycle of plants like the carrot, beetroot is of two years. They are called biennials. Shrubs like the hibiscus and oleander and trees like mango and gulmohur live for several years and bear flowers and fruit. They are called perennials. According to the period of their lifecycle, plants are classified as annuals, biennials, perennials. 21  Can you tell ? To which part of plants are butterflies and insects attracted ? Plants that bear flowers are called flowering plants, while the plants that never bear flowers are called non-flowering plants. Non-flowering plants may not have organs like roots, stems, leaves. Do you know ? Use your brain power ! The world’s largest flower is found in What type of plants are Indonesia. The diameter of the flower of the toadstools and mushrooms ? plant Rafflesia arnoldi is about one metre. The What type of plant is the world’s smallest flower is of the plant called fig ? Wolffia or duckweed. Its diameter is as small as 0.5 mm. Do ferns, algae, money plant bear flowers ? Can you tell ? 1. Where does the pomegranate shrub grow ? 2. Where does the lotus grow ? 3. Where do bulrushes, the railroad creeper grow ? 4. Where does the dodder plant grow ? We see different plants growing in different places around us. Plants can be classified according to their habitat or the place where they grow. Land, water, marshy areas, deserts and even a big tree are the various habitats of plants. Water Land A desert Use your brain power ! Why does the water hyacinth float on water ? Why is the stem of the cactus fleshy ? What different criteria are used to 3.5 : Habitats of plants classify plants ? 22 Diversity and classification in animals Different animals have developed different shapes to survive in the environment. There is a great variety in the body structure of animals too. The amoeba that cannot be seen with our eyes, the huge elephant, the small snail, the fish that swims in water, a kite that flies high in the sky, butterflies that flit around flowers, a house lizard that crawls on a wall are all animals. Each has different characteristics. Animals have body parts like a head, a neck, a torso, a tail and limbs for movement. They have various organ systems which carry on various functions inside their body. In this respect, too, there is a lot of diversity in animals. Can you tell ? What are the differences in the body structure of animals like a snake, a lizard, a tiger, a fish, an eagle, a hen, a crab, a housefly, an earthworm, a crocodile and a grasshopper ? We see a variety in animals with respect to their food as well. Since animals depend on others for their food, they are found in places where food is available. Different animals have different methods of obtaining and eating food. This, too, leads to differences in their body structure. 3.6 : Diversity in animals Observe the animals in your surroundings. Make a list of their names. Try this. Complete the following table on the basis of the information obtained and discuss it in the class. Name of the What is their food ? Where do they live ? The special feature that animal How do they eat it ? you found You will not see all animals in your own surroundings. Why is it so ? Which are the other animals that you know of, but have not seen ? Collect information about them using the above table. Take the help of websites like www.earthlife.net, www.discovery.com, www.seaworld.org, www.kidsgowild.com, www.worldwildlife.org, www.nationalgeographic.com. 23  Take a drop of water from a puddle and place it on a glass slide. Observe it under a microscope. What do you see ? Try this. When a drop of water from a puddle is seen under a microscope, innumerable microbes can be seen moving about in it. You will see the continuously moving amoeba. The paramoecium is also a unicellular animal like the amoeba. A horse, a bear, a tortoise are multicellular animals. Can you tell ? 1. What is the chain of bones in the centre of our back called ? Animals with a vertebral column and those without it form two groups known as the vertebrates and invertebrates, respectively. Snakes, birds, fish and kangaroos as also humans are vertebrate animals. Animals such as snails, cockroaches, earthworms do not have a vertebral column and therefore they are invertebrate animals. 2. Name some animals which lay eggs and others which give birth to their young ones. We have learnt that producing another living thing like oneself is called reproduction. A hen lays eggs and hatches them. After a few days, the young chicks hatch out of the eggs. A cow gives birth to a calf. Before that, the calf grows within the cow’s body. According to the mode of reproduction, animals are classified into two types, namely, oviparous animals which lay eggs and viviparous animals which give birth to their young ones. 3. Where are the animals, namely, a horse, a bear, a tortoise, an alligator, a fish, a deer and a frog to be found ? According to their habitat, animals are usually classified into terrestrial and aquatic animals. However, animals like a frog, salamander, toad live in both places, namely, land and water. Therefore, they are called amphibious animals. A kite, an eagle, a crow, a butterfly, a honeybee all fly in the air, though they live in difference places. These animals are said to have an aerial mode of life. What are the different criteria used to classify Use your brain power ! animals ? 24  Always remember... What we have learnt- In the living world, a lot of diversity l Plants are classified on the basis of their is seen both in animals and plants. height and the shape of stems, period of Every plant and animal is unique. We life cycle and habitat. should all make efforts to conserve l Animals are classified on the basis of the this diversity in the living world. cell structure, vertebral column, method of reproduction and habitat. Exercise 1. Match the pairs. (g) A biennial plant A Group B Group (h) A perennial plant (a) Amphibian (1) A Monkey 6. Write answers to the following. (b) Vertebrate (2) A Snake (c) With scales (3) A Frog (a) What are the parts of a plant ? 2. Who is the odd one out ? (b) What are the functions of the root ? (a) Fungus, mushroom, chrysanthemum, (c) Why is it necessary to classify living spirogyra things ? (b) Mango, banyan, palm, chick pea (d) What are the criteria used to classify (c) Grape, orange, lemon, hibiscus living things ? (d) Sunflower, banyan, jowar, bajra (e) Tell some characteristics of (e) Guava, radish, carrot, beetroot creepers. (f) Deer, fish, man, worms (f) Explain the characteristics of herbs with two examples. 3. What is the difference ? (g) On the basis of which criteria will (a) Flowering plants – non-flowering you classify plants and animals ? plants (h) What protects the bodies of animals? (b) A tree – a shrub (c) Vertebrates – invertebrates 7. Draw figures. 4. True or false ? Draw the figure of a plant to show the (a) The snail is an aquatic animal. parts, namely, the root, stem and leaves (b) Amphibians can live in air and in in it. water. Activity : (c) The function of the brain is well developed in vertebrate animals. l Visit a plant nursery and classify the (s) The amoeba is a multicellular plants there. animal. l Visit a zoo and obtain information about the diversity in animals. 5. Write two names of each. l Write an essay on diversity in plants. (a) A flowering plant (b) A non-flowering plant l Collect seeds of various plants (c) A tree during summer and throw them in (d) A shrub open spaces (fallow land, moorland, (e) A creeper hill, etc.) during the rainy season. (f) An annual plant lll 25  4. Disaster Management Can you tell ? 1. What events do you see in these pictures ? 2. What would you have done in these situations ? 3. Have you experienced such a situation yourself ? 4. Why do these events occur ? 4.1 : Some disastrous events Disaster l In 1993, many people died due to the earthquake at Killari in Latur district. l Even today people of Mumbai shudder at the memory of July 2005 when many people had lost their lives in the deluge caused by heavy rains. 4.2 : Effects of the earthquake at Killari l In July 2014, the whole village of Malin in Ambegaon taluka of Pune district was destroyed in a matter of minutes due to a landslide. Many got buried under the heaps of soil and stone and lost their lives. l In November 2015, many people died 4.4 : The disaster at Malin village due to the flooding caused by heavy rains in Tamil Nadu. Use your brain power ! What is a ‘disaster’? A sudden event that causes large scale 1. What disasters can occur in school damage to life, property and social or on the way to school ? aspects of a nation or society is called 2. According to you, what can be done a distaster. to deal with such a disaster ? 26 How and why do the following Classify the following disasters disasters occur ? as man-made or natural : Fire, 1. Floods due to heavy rains. earthquake, leakage of chemical 2. An earthquake, lightning, a volcanic gases, storms, floods, tsunami, bomb eruption, etc. explosion, collapse of a building, war, 3. Forest fires forest fire. 4. Increased risk due to high density of Man-made Natural disasters population in a limited area. disasters 5. Rampant and irregular constructions. Fire Earthquake 6. Ecological imbalance. 7. Terrorism, riots and crimes resulting in bomb explosions, assaults, fire and accidents, etc. Disasters are of two main kinds - man-made and natural. Effects of earthquake Earthquakes l Destruction of infrastructure, i.e., Movements in the interior of the earth buildings, bridges, roads, railway release tremendous amounts of energy. This tracks, etc. causes seismic waves leading to movements l Change in the direction of the flow of of the earth’s surface like tremors, shaking, rivers. cracking up, etc. l Huge loss of life and property. Such vibrations or quaking in the earth’s crust is known as an earthquake. It is believed that besides other causes, man-made causes like mining and construction of big dams can also lead to earthquakes. Floods A frequently occuring natural disaster in all parts of the world is ‘floods’. Due to excessive rains in the same place, a river overflows its banks causing a flood. The water drainage system in big cities falls short when there is heavy rainfall, resulting in choking of gutters and drainage lines. Water overflows on to the roads and surrounding areas and even enters nearby houses. Effects of floods l Huge loss to life and property. l Soil erosion. l Destruction of standing crops. l After - effects of floods, like spread of diseases and epidemics affecting the health of the people. 4.4 : A flood 27 Storms The formation of high and low air pressure belts in the atmosphere causes changes in weather resulting in strong winds or storms. Effects of storms l Great damage in the storm affected region. l Tremendous losses to life and property. l Disruption of electric supply. l Disruption of transport and communication. 4.5 : A storm Forest fires A forest fire is an uncontrolled fire in a forest, pasture or grassland due to natural or man-made causes. Forest fires spread at a tremendous speed. Effects of forest fires l Great damage to natural wealth and biodiversity. l Pollution of air. 4.6 : A forest fire 1. How many children are there in your class at present ? Can you tell ? 2. What would happen if five times this number sat in your class ? 3. Which kind of disaster can occur in an extremely crowded place ? Disaster management Community participation and disaster management are closely related. Taking steps to prevent disasters, making plans to face disasters and developing the capacity for that, is called disaster management. To prevent or reduce damage caused by natural or man-made disasters, emergency planning and management is required. Institutes at work Always remember... The National Disaster Management Authority was established in 2005. During a disaster, helping and It undertakes planning and supporting each other is our moral implementation of disaster responsibility. management work. Contact them for disaster management Police : 100, Fire Brigade : 101, Ambulance : 102, Disaster management cell : 108 28 Remedial and preventive measures Let us see what precautions we can take before or in the event of a natural or man-made disaster. 1. Keep watching TV and radio news and bulletins. 2. Use battery operated radios and mobiles. 3. Heed the warnings issued by the Meteorological Department carefully. 4. Use the website www.imd.gov.in 5. Landslides occur in hilly areas due to a cloudburst or heavy rains. On such occasions, do not take shelter at the foot of a hill. 6. During floods, do not linger in houses or areas on river banks. Seek shelter in other safe places. Move to safer places at a greater height. Do not step into the water currents or drive a vehicle into them. 7. During an earthquake, roads split open, the ground cracks, railway tracks get uprooted. Hence, when moving from one place to another, ensure that the road is safe further on. 8. Take shelter in relief camps as they provide medicines, food packets, drinking water, first aid, etc. 9. To get protection from fire, use fire extinguishers in public places like schools, hospitals, railway stations, etc. 4.7 : Remedial and preventive measures First aid In day-to-day life, sometimes, we have to face disasters or accidents of varying proportions. On such occasions, it is necessary to give some immediate aid even before medical treatment becomes available. 1. External bleeding 4.8 : Bleeding If a person is bleeding, first make him sit or lie down comfortably. Keep the bleeding part of the body above the level of the heart and clean it with water. 29 2. Burns and scalds Serious burns Minor burns l Give emotional support. l Cover the wounds with sterilised l The injured part should be washed with water or cloth. l Remove jewellery, shoes, etc. if held under water. easily possible. l Give the victim water to l Do not touch or burst the blisters drink. on the skin. l Clean the wounds using a l Do not apply oily ointments. cotton swab soaked in an l Do not try to remove the cloth if it antiseptic solution. is stuck to the burnt skin. l Do not apply oily l If the patient is conscious, give ointments. water to drink but avoid tea or l Cover wounds using dry coffee or other stimulating drinks. dressings. l Get medical aid at once. 4.9 : Immediate steps for burns 3. Sunstroke When we work in the sun continuously for a long time, the body loses a lot of water and minerals. That is the reason for sunstroke. Remedial measures l Take the patient to a cool place or in the shade. l Sponge the whole body with cold water. l Place a cloth soaked in cold water on the neck. l Give plenty of water or liquids like sherbets to drink. l If the patient feels like vomiting make him lie prone, i.e., on his/her abdomen with the head turned to one side. 4.10 : First aid for sunstroke l Get medical help or shift the patient to a hospital. 4. Snakebite There are nearly 2000 species of snakes. Of these, only a few, like cobras, kraits, vipers and sea snakes are poisonous. Therefore, all snakebites are not fatal. However, fear causes severe psychological shock which can result in death. If you come across a snake, contact a ‘Sarpa-mitra’ rather than killing the snake at once. Remedial measures l Wash the wound with water 4.11 : First aid l Give emotional support to the patient. for l Tie a cloth tightly above the wound. snakebite l Get immediate medical help. 30 5. Dog bite Remedial measures In a dog bite, there is a risk of l Wash the wound with a solution of potassium infection through the blood, hence permanganate or other antiseptic. first aid and medical help are l Cover the wound with a clean and dry cloth. necessary. l Get a doctor’s help and an injection of the anti rabies vaccine. What we have learnt- Page 26 : l A sudden calamity is known as a ‘disaster’. Photographs of l Disasters can be man-made or natural. Killari earthquake l Alertness and immediate action are necessary on such occasions. and Malin landslide - l Effective disaster management and use of remedial measures can Courtesy : help reduce the losses. Lokmat Library, l Every person should know about safety precautions and first aid. Aurangabad Exercise 1. What are the emergency contact 5. Find out about the work of a numbers of the following ? ‘Sarpa-mitra’. (a) Police Control Room 6. Find out what a first aid kit/box (b) Fire brigade contains. (c) Ambulance 7. Suggest remedial measures for dealing (d) National level single emergency with natural or man-made disasters. number for disaster relief. Disaster Remedy Disaster Remedy 2. What first aid will you provide in Fire Earthquake the following situations ? Building Deluge (a) Dog bite collapse (b) Scratches/ bleeding Road Storm accident (c) Burns/scalds Flood Tsunami (d) Snakebite (e) Sunstroke War Drought 3. Write the causes of the following : Bomb Landslide explosion (a) Floods (b) Forest fires Activity : (c) Land slides/building collapse l Compile information about measures (d) Storms taken for disaster management in (e) Earthquakes your school. 4. Answer the following questions. l Make posters, advertisements, (a) What is meant by ‘disasters’ ? banners about disaster management. (b) What are the types of disasters? (c) What is meant by ‘disaster l Find out the people/organisations that management ’? provide aid during a disaster. Obtain (d) Which are the main components of their phone numbers, addresses, etc. disaster management ? lll 31  5. Substances in the Surroundings – Their States and Properties Can you recall ? Name the solid, liquid and gaseous states of water. Change of state of substances Pieces of wax Let’s try this. Melting wax Take pieces of wax in a bowl and heat them on a candle or spirit lamp. 1. How do the pieces of wax change ? 2. What was the initial state of wax ? Spirit lamp 3. What did it get converted into ? Now keep the same bowl in cold water. What happens ? Wax in the When a substance changes from one solid state state to another, the process is called change of state of the substance. 5.1 : Change of state of wax Can you tell ? Read this list of substances : Spirit, camphor, petrol, ghee, coconut oil, naphthalene balls, ammonium chloride (navsagar). 1. Which ones freeze in winter ? 2. Which liquid have you seen change into a vapour ? 3. Which solids directly change into the gaseous state ? 5.2 : Various substances What do we learn from this ? In the past... The state of a substance changes if In the 19th century, the scientist it is heated or cooled. Every J. Willard Gibbs showed that the substance in our surroundings, characteristic properties of a substance is found in either the solid, liquid, depend on its physical state and the or gaseous state. arrangement of particles in it. 32  Points Solids Liquids Gases Example A piece of iron