General Science Class 7 Semester 1 Textbook PDF

7 GENERAL SCIENCE “The world as we have created it is a process of our thinking. It cannot b...

7 GENERAL SCIENCE “The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.” - Albert Einstein General Science kÍeÖq« Xæg+ Semester (™d$TdŸ¼sY) - 1 CLASS VII State Council of Educational Research & Training Andhra Pradesh Semester (™d$TdŸ¼sY) - 1 Free distribution by Samagra Shiksha, Government of Andhra Pradesh  SCIENCE TEXTBOOK FOR CLASS VII Semester - 1 State Council of Educational Research & Training Andhra Pradesh  © Government of Andhra Pradesh, Amaravati First Published 2023 New Impression - 2024 All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior permission in writing of the publisher, nor be otherwise circulated in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser. The copyright holder of this book is the Commissioner of School Education, Amaravati, Andhra Pradesh. This book has been printed on 70 G.S.M. SS Maplitho Title Page 220 G.S.M. White Art Card Free distribution by Samagra Shiksha, Government of Andhra Pradesh Printed in India at the A.P. Govt. Text Book Press Amaravati Andhra Pradesh  SCIENCE Class - VII Semester - 1 Text Book Development Committee Sri Praveen Prakash IAS Sri. S. Suresh Kumar IAS Principal Secretary to Government Commissioner of School Education , AP Department of School Education, AP Sri. B. Srinivasa Rao IAS Sri. K. Ravindranath Reddy MA., B.Ed. State Project Director, Samagra Shiksha, AP Director, Government Textbook Press, AP Dr. B. Pratap Reddy MA., B.Ed., Ph.D. Director, SCERT, AP Programme Co-ordinator Dr. G. Kesava Reddy, MSc, MSc, MEd, MPhil, PhD Prof. C&T, SCERT, AP Subject Co-ordinators Smt. Kasula Rama Mani Sri Dasaripalle David Prof. in Biology, SCERT, AP Lecturer in Biology, SCERT, AP Smt. Miryala Neelima Faculty, SCERT, AP Technical Co-ordinator Dr. Ch.V.S. Ramesh Kumar Faculty, SCERT-AP Published by Samagra Shiksha, Government of Andhra Pradesh, Amaravati.  Editors for Translation Dr. Y. Giri babu Yadav Dr. S. Rajeswari Prof. SCERT, AP Prof. SCERT, AP Sri N. Prakash Muktipudi Smt. Vangeepuram Swarna Latha Lecturer in Zoology, SCERT, AP Lecturer, SCERT, AP Translators Sri P. Satya Prakash, SA (BS) Sri Md. Zakir Ahmed, SA (BS) ZPHS, Kondagumpam, VZM Dist SMK ZPHS, Movva, Krishna Dist Sri Sk. Mohammad Gouse, SA (BS) Sri M. Srinivasarao, SA (PS) STKS, ZPHS, Kotappa Konda, SPSMH School, Gudivada, Palnadu Dist Krishna Dist Smt G. Nivedita, SA (BS) Sri K. Ravi Kumar, SA (BS) ZPHS, Valluru, Prakasam Dist SABS, ZPHS, Machavaram, Dr. BR. Ambedkar Konaseema Dist Sri K. Sairam, SA (BS) ZPHS, Kondukuduru, Sri V. Ravindra Reddy, SA (BS) Dr. BR. Ambedkar Konaseema Dist TVC Govt. H School, Annamayya Dist Sri S. Brahmananda Reddy, SA (PS) Smt K. Manjula, SA (BS) ZPHS, Vallicherla, Prakasam Dist ZPHS, Palasamudram, Sri Satya Sai Dist Sri P. Govinda Rao, SA (BS) Sri K. Vijaya Kumar, SA (BS) ZPHS, Budamuru, Srikakulam Dist ZPHS, Ragulapadu, Anantapuramu Dist Sri KOVSSNR Subrahmanyam, SA (PS) Smt B. Purnima, SA (PS) ZPHS, Mallicherla, Vizianagaram Dist ZPHS, Jangareddy Gudem, Eluru Dist Designing & Page Layout Stock Assortment, Bapatla.  FOREWORD The National Curriculum Framework (NCF), 2005, recommends that children’s life at school must be linked to their life outside the school. This principle marks a departure from the legacy of bookish learning which continues to shape our system and causes a gap between the school, home and community. The syllabi and textbooks developed on the basis of NCF signify an attempt to implement this basic idea. They also attempt to discourage rote learning and the maintenance of sharp boundaries between different subject areas. We hope these measures will take us significantly further in the direction of a child-centred system of education outlined in the National Policy on Education (1986). The success of this effort depends on the steps that school principals and teachers will take to encourage children to reflect on their own learning and to pursue imaginative activities and questions. We must recognise that, given space, time and freedom, children generate new knowledge by engaging with the information passed on to them by adults. Treating the prescribed textbook as the sole basis of examination is one of the key reasons why other resources and sites of learning are ignored. Inculcating creativity and initiative is possible if we perceive and treat children as participants in learning, not as receivers of a fixed body of knowledge. These aims imply considerable change in school routines and mode of functioning. Flexibility in the daily time-table is as necessary as rigour in implementing the annual calendar so that the required number of teaching days are actually devoted to teaching. The methods used for teaching and evaluation will also determine how effective this textbook proves for making children’s life at school a happy experience, rather than a source of stress or boredom. Syllabus designers have tried to address the problem of curricular burden by restructuring and reorienting knowledge at different stages with greater consideration for child psychology and the time available for teaching. The textbook attempts to enhance this endeavour by giving higher priority and space to opportunities for contemplation and wondering, discussion in small groups, and activities requiring hands-on experience. The National Council of Educational Research and Training (NCERT) appreciates the hard work done by the Textbook Development Committee responsible for this book. We wish to thank the Chairperson of the advisory group in Science and Mathematics, Professor J.V. Narlikar and the Chief Advisor for this book, Prof. V.B. Bhatia for guiding the work of this committee. Several teachers contributed to the development of this textbook; we are grateful to their principals for making this possible. We are indebted to the institutions and organisations which have generously permitted us to draw upon their resources, material and personnel. We are especially grateful to the members of the National Monitoring Committee, appointed by the Department of Secondary and Higher Education, Ministry of Human Resource Development under the Chairpersonship of Professor Mrinal Miri and Professor G.P. Deshpande, for their valuable time and contribution. As an organisation committed to systemic reform and continuous improvement in the quality of its products, the NCERT welcomes comments and suggestions which will enable us to undertake further revision and refinement. Director New Delhi National Council of Educational 20 November 2006 Research and Training  PREFACE This book is the outcome of the efforts of the Textbook Development Committee appointed by the NCERT. The committee met a few times to interact with one another to improve the draft. Then there was a review meeting in which many experts and practicing school teachers were invited to review the draft and suggest improvements. By and large we have stuck to the format of the Class VI book. By now, famous characters, Boojho and Paheli, have been used to make the text interactive. Attempt has been made to recall children’s own experiences and build concepts around them. This is designed to connect science that they study in the school with their every-day life. Many activities have been suggested to clarify concepts. Some of these activities are so simple that children can perform them on their own. The requirement of the apparatus required for the activities is minimal. We performed all the activities ourselves to ensure that there was no difficulty in performing them in the school situation. The activities should also help children in developing skills such as presentation of data in tabular and graphical forms, reasoning and drawing inference from the given data. The language of the book has been kept as simple as possible. A large number of photographs, illustrations, cartoons, etc. have been included to make the book attractive. To help teachers evaluate children effectively, a large number of exercises have been given at the end of each chapter. The teachers are encouraged to frame additional exercises to test children’s understanding. Some challenging exercises have also been devised for those children who would like to appear for the National Talent Search Examination conducted by the NCERT. We are conscious of the fact that there is a paucity of additional reading material for children. We have tried to address this problem by providing non-evaluative boxes. These boxes, in blue, contain additional information, anecdotes, stories, strange facts and other such interesting materials. We all know that children are mischievous and playful by nature. Therefore, in order to prevent any untoward incident during the performance of the activities in the school or outside, necessary cautions, in red, have been inserted at various places in the book. To prepare children to assume their roles as responsible citizens of tomorrow, attempt has been made to sensitise them to the issues concerning gender, religion, environment, health and hygiene, water scarcity and energy conservation. We have sought to weave into the text the value of cooperation and the importance of peer learning. An important feature of the book is what we call ‘Extended Learning’. These are totally non-evaluative, and purely voluntary activities and projects. Some of the projects in this section have been designed to enhance children’s interaction with the experts, teachers, even parents, and society at large. The children are required to collect information of various kind and draw conclusions of their own. My request to teachers and parents is to use the book in the spirit in which it has been written. Encourage children to perform activities and learn by doing, rather than by rote.  viii You can supplement, or even replace, the activities given here. If you feel that you have better alternatives, especially with your local/regional flavour, please write to us so that these activities could be used in the future editions of the book. We have been able to include only a small subset of children’s experiences. You have a better knowledge of their experiences because you are in touch with them. Use them to illustrate the concepts being taught. Above all, please do not stifle children’s natural curiosity. Encourage them to ask questions, even if sometimes you feel uncomfortable. If you do not know the answer to a question on the spot, do not feel embarrassed. You can promise them to find the answer and deal with it later. Make a genuine attempt to get the answer from whatever resources are within your reach, such as senior school or college teachers, experts, libraries, internet, etc. If, in spite of your efforts, you cannot get the answer to some question, you could write to NCERT. I must thank the NCERT for enabling us to talk to children through the medium of this book. Every member of the NCERT has been courteous and helpful to us. If you find this book useful and enjoy teaching/learning science through this book, the Editing Team and I shall consider ourselves well-rewarded. V.B. BHATIA Chief Advisor Textbook Development Committee TEXTBOOK DEVELOPMENT COMMITTEE (NCERT) CHAIRPERSON , ADVISORY GROUP FOR TEXTBOOKS IN SCIENCE AND MATHEMATICS J.V. Narlikar, Emeritus Professor, Inter University Centre for Astronomy and Astrophysics (IUCCA), Ganeshkhind, Pune University, Pune CHIEF ADVISOR V.B. Bhatia, Professor, Retd. (Physics), Delhi University, Delhi MEMBERS Bharati Sarkar, Reader, Retd. (Zoology), Maitreyi College, Delhi University, Delhi C.V. Shimray, Lecturer, Department of Education in Science and Mathematics (DESM), NCERT, Sri Aurobindo Marg, New Delhi D. Lahiry, Professor, Retd, DESM, NCERT, Sri Aurobindo Marg, New Delhi G.P. Pande, Uttarakhand Seva Nidhi, Paryavaran Shiksha Sansthan, Jakhan Devi, Almora, Uttaranchal Harsh Kumari, Headmistress, CIE Experimental Basic School, Department of Education, Delhi University, Delhi J.S. Gill, Professor, DESM, NCERT, Sri Aurobindo Marg, New Delhi Kamal Deep Peter, TGT (Science), Kendriya Vidyalaya, Bengaluru Kanhiya Lal, Principal, Retd., Directorate of Education, Delhi Lalita S. Kumar, Reader (Chemistry), School of Sciences, Indira Gandhi National Open University (IGNOU), Maidan Garhi, New Delhi Mohd. Iftikhar Alam, TGT (Science), Sarvodaya Bal Vidyalaya (No.1), Jama Masjid, Delhi P.S. Yadava, Professor, Department of Life Sciences, Manipur University, Imphal R. Joshi, Lecturer (Selection Grade), DESM, NCERT, Sri Aurobindo Marg, New Delhi Rachna Garg, Lecturer, DESM, Central Institute of Educational Technology, NCERT, Sri Aurobindo Marg, New Delhi Ranjana Agrawal, Principal Scientist and Head, Division of Forecasting Techniques, Indian Agricultural Statistics Research Institute, IARI Campus, Pusa, New Delhi R.S. Sindhu, Professor, DESM, NCERT, Sri Aurobindo Marg, New Delhi Ruchi Verma, Lecturer, PPMED, NCERT, Sri Aurobindo Marg, New Delhi Sarita Kumar, Reader (Zoology), Acharya Narendra Dev College, Delhi University, Delhi Sunila Masih, Teacher, Mitra GHS School, Suhagpur, P.O. Hoshangabad, Madhya Pradesh V.K. Gupta, Reader (Chemistry), Hans Raj College, Delhi University, Delhi MEMBER-COORDINATOR R.K. Parashar, Lecturer, DESM, NCERT, Sri Aurobindo Marg, New Delhi  RATIONALISATION OF CONTENT IN THE TEXTBOOKS In view of the COVID-19 pandemic, it is imperative to reduce content load on students. The National Education Policy 2020, also emphasises reducing the content load and providing opportunities for experiential learning with creative mindset. In this background, the NCERT has undertaken the exercise to rationalise the textbooks across all classes. Learning Outcomes already developed by the NCERT across classes have been taken into consideration in this exercise. Contents of the textbooks have been rationalised in view of the following: Overlapping with similar content included in other subject areas in the same class Similar content included in the lower or higher class in the same subject Difficulty level Content, which is easily accessible to students without much interventions from teachers and can be learned by children through self-learning or peer-learning Content, which is irrelevant in the present context This present edition, is a reformatted version after carrying out the changes given above.  ACKNOWLEDGEMENTS The National Council of Educational Research and Training (NCERT) acknowledges the valuable contribution of the individuals and organisations involved in the development of Science textbook for Class VII. The Council acknowledges the valuable contribution of the following academics for reviewing and refining the manuscripts of this book: Sushma Kiran Setia, Principal, Sarvodaya Kanya Vidyalaya, Hari Nagar (Clock Tower), New Delhi; Mohini Bindra, Principal, Ramjas School, Pusa Road, New Delhi; D.K. Bedi, Principal, Apeejay Senior Secondary School, Pitampura, Road No. 42, Sainik Vihar, New Delhi; Chand Vir Singh, Lecturer (Biology), GBSS School, Rajouri Garden (Main),New Delhi; Renuka Madan, TGT (Physics), Air Force Golden Jubilee Institute, Subroto Park, Delhi Cantt; Reena Jhani, TGT (Science), Darbari Lal DAV Model School, Pitampura, New Delhi; Geeta Bajaj, TGT (Science), K. V. No. 3, Delhi Cantt., New Delhi; Gagandeep Bajaj, Lecturer, Department of Education, S.P.M. College, Delhi University, Delhi; Shashi Prabha, Lecturer, DESM, NCERT, New Delhi; A.K. Bakhshi, Professor, Department of Chemistry, University of Delhi, Delhi; N. Rathnasree, Director, Nehru Planetarium, Teen Murti Bhavan, New Delhi; S.B. Singh, TGT (Science), J.N.V. Sonikpur, P.O. Trivediganj, Distt. Barabanki, Uttar Pradesh; Madhur Mohan Ranga, Lecturer (Selection Scale), (Zoology), Govt. College, Ajmer, Rajasthan; K.G. Ojha, Associate Professor, Department of Chemistry, M.D.S. University, Ajmer, Rajasthan; Puneeta Sharma, TGT (Science), L.D. Jain Girls Senior Secondary School, Pahari Dhiraj, Delhi; Manohar Lal Patel, Teacher, Govt. R.N.A. Exc. H.S.S. Pipariya, Distt. Hoshangabad, Madhya Pradesh; Bharat Bhushan Gupta, PGT (Biology), Sarvodaya Vidyalaya, No.1, Shakurpur, Delhi; Sushma Jairath, Reader, Department of Women Studies (DWS), NCERT, New Delhi; Mina Yadav, Lecturer, DWS, NCERT, New Delhi; Swadesh Taneja, Ex-Reader (Life Sciences), IGNOU, New Delhi and M.M. Kapur, Professor, Retd. (Chemistry), Delhi University, Delhi. The contributions of Pramila Tanwar, R.R. koireng and Ashish K. Srivastava, Assistant Professors, are acknowledged for being a part of the review of this textbook. The Council is highly thankful to the India Meteorological Department, New Delhi, for providing some illustrations for the Chapter 8: Winds, Storms and Cyclones. The Council gratefully acknowledges the valuable suggestions received from the National Monitoring Committee in the development of the manuscript of this textbook. The dynamic leadership of Professor Hukum Singh, Head, DESM, for providing guidance in the final editing of the manuscript and extending infrastructure facilities is highly acknowledged. Special thanks are due to Shveta Uppal, Chief Editor; and Bijnan Sutar, Assistant Editor, for going through the manuscript and suggesting relevant changes. The Council also acknowledges the efforts of Deepak Kapoor, Incharge, Computer Station; Purnendu Kumar Barik, Musarrat Parveen and Satish Kumar Mishra, Copy Editors; Neelam Walecha and Muhammad Aiyub, DTP Operators; and Randhir Thakur, Proof Reader. The contribution of APC-office, administration of DESM, Publication Department and Secretariat of NCERT is also acknowledged.  xii A NOTE FOR THE STUDENTS The team of Paheli and Boojho will be with you as you journey through this textbook. They love to ask questions. All kind of questions come to their minds and they collect them in their sacks. Sometimes, they may share some of these questions with you, as you read through the chapters. Paheli and Boojho are also on the lookout for answers to many questions — sometimes the questions seem answered after they discuss them with each other, sometimes through discussions with other classmates, teachers or their parents. Answers to some questions do not seem available even after all these. They might need to experiment on their own, read books in the library, send questions to scientists. Just dig and dig and dig into all possibilities and see if the questions can be answered. Perhaps, they would carry some of the unanswered questions in their sacks to higher classes. What will really thrill them would be your adding questions to their sacks or answers to their questions. Sometimes, activities are suggested in the textbook, results or findings of these by different groups of students would be of interest to other students and teachers. You can complete the suggested activities and send your results or findings to Paheli and Boojho. Do keep in mind that activities that involve using blades, scissors or fire need to be done strictly under the care of your teachers. Stick to the precautions given and then enjoy doing all the suggested activities. Mind, the book will not be able to help you much, if the activities are not completed! We would like to advise you that you must make observations yourself and record whatever results you get. Keen and true observations are necessary for exploring any subject of study. For some reason your results may turn out to be different from those of your classmates. Do not worry. Try to find out the reason for these results instead of disregarding To them. Do not ever copy results from your The Head classmate. Department of Education in You can send your feedback for Science and Mathematics, Paheli and Boojho at: NCERT, Sri Aurobindo Marg, New Delhi 110 016  CONTENTS Chapter 1 Nutrition in Plants 2 yîTT¿£Ø\ýË bþwŸD Chapter 2 Nutrition in Animals 22 È+ÔáTeÚ\ýË bþwŸD Chapter 3 Heat 48 –wŸ’+ Chapter 4 Acids, Bases and Salts 76 €eÖ¢\T, ¿Œ±s\T eT]jáTT \eD²\T Chapter 5 Physical and Chemical Changes 94 uó Ü¿£ eT]jáTT sÁkÍjáTq eÖsÁTÎ\T Chapter 6 Respiration in Organisms 114 JeÚ\ýË XæÇdŸç¿ìjáT Chapter 7 T RA NSPORTATION IN A N IMA L S A N D PL A N TS 140 yîTT¿£Ø\T eT]jáTT È+ÔáTeÚ\ýË sÁyD² TEACHER C ORNER S TUDENT C ORNER  1 Nutrition in Plants I n Class VI you learnt that food is utilisation by the body. The mode of essential for all living organisms. nutrition in which organisms make food You also learnt that carbohydrates, themselves from simple substances is proteins, fats, vitamins and minerals are called autotrophic (auto = self; trophos components of food. These components = nourishment) nutrition. Therefore, of food are called nutrients and are plants are called autotrophs. Animals necessary for our body. and most other organisms take in food All living organisms require food. prepared by plants. They are called Plants can synthesise food for heterotrophs (heteros = other). themselves but animals including humans cannot. They get it from plants or animals that eat plants. Thus, humans and animals are directly or Paheli wants to know why indirectly dependent on plants. our body cannot make food from carbon dioxide, water and minerals like plants do. Boojho wants to know how plants prepare Now we may ask where the food their own food. factories of plants are located: whether food is made in all parts of a plant or only in certain parts? How do plants 1.1 MODE OF NUTRITION IN PLANTS obtain the raw materials from the Plants are the only organisms that can surroundings? How do they transport prepare food for themselves by using them to the food factories of plants? water, carbon dioxide and minerals. The raw materials are present in their 1.2 PHOTOSYNTHESIS — FOOD surroundings. MAKING PROCESS IN PLANTS The nutrients enable living Leaves are the food factories of plants. organisms to build their bodies, to grow, Therefore, all the raw materials must to repair damaged parts of their bodies reach the leaf. Water and minerals and provide the energy to carry out life present in the soil are absorbed by the processes. Nutrition is the mode of roots and transported to the leaves. taking food by an organism and its Carbon dioxide from air is taken in 2 NUTRITION IN PLANTS  1 yÓTTø£ÿ\˝À b˛wüD JesêX¯ó\ìï+{ÏøÏ ÄVü‰s¡+ ÄeX¯´ø£eTì MTs¡T Äs¡e Je⁄\T düsfi¡ ¯ |ü± ‘·s>¡ ‹∑ ˝À H˚sT¡ Ã≈£îHêïs¡T. |æ+&ç |ü± ø±˙ yÓTTø£ÿ\ô|’ yÓTTø£ÿ\˝À ÄVü‰sêìï ‘·j÷· s¡T #˚ùd ø£sêà>±sê\T mø£ÿ&É Ä±˝À¢ ‘·j·÷s¡e⁄ ã÷CÀ yÓTTø£ÿ\T ‘·eT ÄVü‰sêìï ‘·T+±˝À¢H˚ ‘·j÷· s¡e⁄‘·T+± m˝≤ ‘·j·÷s¡T yÓTTø£ÿ\T eTT&ç |ü∑Væ≤kÕÔsTT? yê{Ïì yÓTTø£ÿ\˝À ÄVü‰s¡+ ‘·j·÷s¡j˚T´ ø£sêà>±sêìøÏ m˝≤ ‘·s¡*kÕÔsTT? nì Ç|ü⁄Œ&ÉT eTq+ 1.1 yÓTTø£ÿ\˝À b˛wüD≤ $e∑ #·TÃ. yÓTTø£ÿ\T e÷Á‘·y˚T ˙s¡T, ø±s¡“Hé &ӒĬø’‡&é, eT]j·TT Kì» \eD≤\T ñ|üj÷Ó –+#·Tø=ì ‘·eT ÄVü‰sêìï ‘êy˚T dü«j·T+>± 1.2 øÏsD¡ »q´ dü+jÓ÷>∑ ÁøÏjT· - yÓTTø£ÿ\˝À ÄVü‰s¡+ ‘·j·÷s¡T #˚düT≈£îH˚ Je⁄\T. á eTT&ç |ü±sê\T. ø±e⁄q, eTT&ç b˛wüø±\T Je⁄\≈£î ‘·eT X¯Øs¡ ìsêàD≤ìøÏ, ô|s¡T>∑T∑ ÁøÏjT· ˝Òøb£ ˛‘˚ uÛ÷Ñ $Tô|’ Je⁄\ eTqT>∑&É nkÕ∑ ÁøÏj·T »]π>≥|ü⁄Œ&ÉT, |üÁ‘·Vü≤]‘·+ ø£*–q |üÁ‘ê\˝Àì ø£D≤\T, dü÷s¡´s¡ à düeTø£å+˝À |æ+&ç ø±s¡“Hé &Ó’ Ĭø’‡&é |ü∑ÁøÏj·TqT #·÷ù| |ü≥+ |üÁ‘·V≤ü ]‘·+ á Á|ü Á øÏ j · T »]π > ≥|ü ⁄ Œ&É T ÄøÏ ‡ »Hé yêj· T Te⁄ $&ÉT&∑ Üìï ìsê∆]düT+Ô ~. |æ+&ç |ü∑ ÁøÏj·TqT »s¡T|ü⁄‘êjÓ÷ ˝Ò∑T‘·Tqï ˇπø s¡ø£yÓTÆq yÓTTø£ÿ\qT ‘Ó]∫ ñqï |üÁ‘·s¡+Á∑\ ms¡Te⁄\qT H˚\≈£î ø£*ù| ¬s’‘·T\qT #·÷ùd ñ+{≤s¡T. á $± yÓTTø£ÿ\T Ç‘·s¡ n+XÊ\‘√bÕ≥T ‘·eT≈£î nedüsy¡ TÓ qÆ qÁ‘· » ìì |ü P ]+#· T ≈£ î +{≤sTT. ‘· s ¡ T yê‘· yÓ T Tø£ ÿ \T e÷+düø£‘·TÔ\T , Áø=e⁄«\ e+{Ï yê{Ïì dü+X‚¢wækÕÔsTT. 1.3 yÓTTø£ÿ\˝À Ç‘·s¡ b˛wüD $±e⁄qï Ä≈£î|ü#·Ãì ÁbÕ+‘ê\qT MTs¡T ‘·s¡#·T>± b˛wüDqT bı+∑T∑T˝À ô|’ Ä∑\ r>∑ ˝≤+{Ï Ä≈£î|ü#÷ ì s¡+>∑TqT ø£*–+#˚ |üÁ‘· Vü≤]‘êìïø£*– ñ+{≤sTT. ìsêàD≤\T #Ó≥Tº ø±+&É+, ø=eTà\ #·T≥÷º #·T≥Tºø=ì XË’e˝≤\T ≈£L&Ü øÏs¡D»q´ dü+jÓ÷>∑ ÁøÏj·T ±s¡T r>∑) ÄVü‰sêìï ‘êy˚T ‘·j·÷s¡T #˚düT≈£î+{≤sTT. nqã&˚ yÓTTø£ÿ. á yÓTTø£ÿ˝À |üÁ‘·Vü≤]‘·+ ñ+&É∑Áu≤≈£î‘·T+∑ ÁøÏjT· ∑T‘·T+∑T ˝≤+{Ï ìsêàD≤\qT MTs¡T #·÷ùd ñ+{≤s¡T (|ü≥+ 1.7). n$ ô|s¡>∑&ÜìøÏ @$∑Væ≤kÕÔjÓ÷ ‘Ó\TdüT≈£î+∑T‘·Tqï *+Á∑T\ bÕ´¬ø{Ÿ, ≈£î[¢q |ü=&ÉT>∑T XÀwæ+#·T≈£î+{≤sTT. á $± #·ìb˛sTTq, Á≈£î[¢b˛‘·Tqï |ü∑+ ø±s¡“Hé &Ó’ Ĭø’‡&é yêj·TTe⁄qT yÓTTø£ÿ˝Àì @ uÛ≤>∑+ >±*qT+&ç ˝À|ü*øÏ rdüT≈£î+≥T+~. (i) eT÷\πøXÊ\T (ii) |üÁ‘·s¡+Á± @s¡Œs¡TkÕÔsTT. yÓTTø£ÿ\˝À b˛wüD 21  2 Nutrition in Animals Y ou have learnt in Chapter 1 that food into simpler substances is called plants can prepare their own food digestion. by the process of photosynthesis 2.1 DIFFERENT WAYS OF TAKING FOOD but animals cannot. Animals get their The mode of taking food into the body food from plants, either directly by varies in different organisms. Bees and eating plants or indirectly by eating humming-birds suck the nectar of animals that eat plants. Some animals plants, infants of human and many eat both plants and animals. Recall that other animals feed on mother’s milk. all organisms including humans require Snakes like the python swallow the food for growth, repair and functioning animals they prey upon. Some aquatic of the body. Animal nutrition includes animals filter tiny food particles floating nutrient requirement, mode of intake nearby and feed upon them. of food and its utilisation in the body. You have studied in Class VI that food Activity 2.1 consists of many components. Try to What is the type of food and mode of recall and list them below: feeding of the following animals? Write 1. ______________________ down your observations in the given 2. ______________________ Table. You may find the list of modes of feeding given below the Table helpful. 3. ______________________ Table 2.1 Various modes of feeding 4. ______________________ 5. ______________________ Name of Kind of Mode of animal food feeding 6. ______________________ Snail The components of food such as Ant carbohydrates are complex substances. Eagle These complex substances cannot be Humming-bird utilised as such. So they are broken Lice down into simpler substances. The Mosquito breakdown of complex components of Butterfly House fly (Scraping, chewing, siphoning, capturing Complex substance Simpler substances and swallowing, sponging, sucking etc.) 22 NUTRITION IN ANIMAL  2 »+‘·Te⁄\˝À b˛wüD øÏs¡D»q´ dü+jÓ÷>∑ÁøÏj·T ± e÷s¡Ã&Üìï Js¡íÁøÏj·T n+{≤s¡T. ‘êy˚T ‘·j·÷s¡T #˚düTø√>∑\e⁄, ø±˙ »+‘·Te⁄\T #˚j·T˝Òeì 2.1 ÄVü‰sêìï rdüT≈£îH˚ $$