SECONDARY BIOLOGY

Prescribed by the National Curriculum and Textbook Board forClass IX-X from the academic year of 1996.SECONDARY BIOLOGYClass IX-XWritten byDr. Iqubal Aziz MuttaquiNasim BanuDr. Md. Abul HasanGul Anar AhmedTranslated byProfessor Md. Obaidur Rahman SikderRaihana BegumNational Curriculum And Textbook Board, Dhaka

Published byNational Curriculum and Textbook Board67-70, Motijheel Commercial Area, Dhaka[All rights reserved by the Publisher]First Print : 1998Second Edition: 2007Reprint April : 2009Reprint October :Computer ComposePerform Color Graphics (Pvt) Ltd.IllustrationArif Reza KhanAbu Hasmi Md. FaisalDesignNCTB, DhakaFor free distribution from academic year 2012 by the Government of Bangladesh.Printed by :

PREFACEEducation is the key to development. A progressively improved educationsystem largely determines the pace and the quality of national development. Toreflect the hopes and aspirations of the people and the socio-economic andcultural reality in the context of the post independent Bangladesh, newtextbooks were introduced in the beginning of the 1980s following therecommendations of the National Curriculum and Textbook Committee.In 1994, in accordance with the need for change and development, thetextbooks of lower secondary, secondary and higher secondary were revisedand modified. The textbooks from classes VI to IX were written in 1995. in2000, almost all the textbooks were rationally evaluated and necessary revisionwere made. In 2008, the Ministry of Education formed a Task Force forEducation. According to the advice and guidance of the Task Force, the cover,spelling and information in the textbooks were updated and corrected.To make assessment more meaningful and in accordance with the need of thecurriculum, Creative Questions and Multiple Choice Questions are given at theend of each chapter. It is hoped that this will reduce the dependency of studentson rote memorisation. The students will be able to apply the knowledge theyhave gained to judge, analyses and evaluate real life situation.In the revised curriculum. Botany & Zoology has been included in one bookBiology. The study of Biology has been Presanted through both theory andpractical classes. The practical experiments have been given separately.Students can gain knowledge about Biology and their interest in science willincrease when they complete the experiments with the help of the teachers. Ihope that the textbook of Biology properly reflects the objectives of thecurriculum.This book of Biology for class IX & X is the English Version of the originaltextbook entitled 'Maydhamic Gibobiggayan' written in Bangla.We know that curriculum development is a continuous process on whichtextbooks are written. Any logical and formative suggestions for improvementwill be considered with care. On the event of the golden jubilee of theIndependence of Bangladesh in 2021, we want to be a part of the ceaselesseffort to build a prosperous Bangladesh.In spite of sincere efforts in translation, editing and printing some inadvertenterrors and omissions may be found in the book. However, our efforts to makeit more refined and impeccable will continue. Any constructive suggestiontowards its further improvement will be gratefully considered.I thank those who have assisted us with their intellect and effort in the writing,editing and rational evaluation of this book. We hope that the book will beuseful for the students for whom it is written.Prof. Md. Mostafa KamaluddinChairmanNational Curriculum and Textbook BoardDhaka

ContentsChapterTopicsPage1Introduction to Biology12Structure and Nature of living Cell153Cell Division284Division of Labour in Multicellular Plants: Tissue and36Tissue System5Animal Tissue, Organ and Organ System466Classification of Plants627Animal Diversity and Classification788Structural Organization and Acquaintance of Animals959Physiological Activities in Plants : Nutrition164Imbibition, Osmosis, Ascent of Sap And Transpiration168Photosynthesis and Respiration182Growth and Development of Plants19910Flower20711Pollination, Fertilization and dispersal of fruits and216seeds12Reproduction of Plants22813Organism and Environment23214Pollution and Conservation of Environment24715Natural Diversities of Bangladesh-Distribution of260Plants and Animals16Economic Biology300Practical Botany314Practical Zoology334

CHAPTER ONEINTRODUCTION TO BIOLOGYNow a days we find contributions of Aristotle, Socrates, Theophrastus andmany other scholars of the past age in different fields of knowledge. This is notpossible for the scholars of the present time. A question may arise in your mindas to why it is not possible today. The reason is that in ages long past the extentof knowledge was limited. People engaged in achieving knowledge were alsosmall in number. Today the dimension of knowledge has been increased manytimes. To contribute in more than one field is quite difficult at the present time.For convenience to know and understand things we have divided our world ofknowledge in many branches. In this way Science, Literature, Arts, SocialScience and many other branches have been created. As a whole, knowledge ofhuman beings is undivided. But it has been divided into various branches foreasy learning and understanding.You may have known that the knowledge of science is increasing rapidly. It isbecoming possible because of the research of a large number of scientists indifferent fields of science. Many people think that knowledge of science isbecoming double in every eight years. New subjects of science are beingcreated. It is not possible to realize and understand this huge store ofknowledge for an individual alone. As a result, scientists are engaged inresearch in particular subject or topic. At different times many scholars havedivided the knowledge of science in various ways. The division and differentbranches of science are constantly spreading with the increase of knowledge inscience. The two main branches of science are Physical science and BiologicalScience.Physical Science is otherwise called the Science of non-living things. InPhysical science characteristics, actions-reactions, multiformaity and manysimilar other properties of non-living objects are examined and discussed.

2Secondary BiologyObservation, examination and discussion of livings beings are included inBiology. Biology is the science of living beings. The term Biology comes fromtwo Greek words (bios means life and logos means knowledge). Aristotle isregarded as the father of Biology.We find two types of life in nature. One is plant while the other is animal.Accordingly Biology has been divided into two branches: Botany and Zoology.Botany deals with theoretical discussion and research about characters andother features of plants, while Zoology is limited in subjects relating toanimals.PRINCIPAL BRANCHES OF BIOLOGYBiology has been divided into Botany and Zoology on the basis of nature ofliving beings. Inspite of this, now-a-days extensive research has been done onMicroorganism. They influence human life in various ways. So for discussionabout them a new branch is made. This is known as Microbiology.Considering the subjects of living bodies on which discussion is made thewhole range of Biology is divided into the following main branches.1. Morphology: This branch deals with both the external and internalstructures of organism. The subject concerning internal . structures is alsoknown as Anatomy.2. Cytology: Each living organism consists of one or more cells. Structuresand functions of cells are treated in this branch of Biology.3. Histology: In this branch discussion is made on structure, location andfunction of different tissues.4. Physiology: This branch includes all the activities of living things e.ggrowth respiration, excretion, photosynthesis and other biological activities.5. Taxonomy: In this branch discussion is made on identificationnomenclature, and classification of plants and animals into groups andsubgroups.

Intorduction to Biology36. Genetics: How different characters are inherited from parents to offsprings,and how the processes can be controlled and improved etc. are brought understudy and research in this branch.7. Ecology: This branch considers the effects of environment on livingorganisms or living communities and also interaction between them.8. Evolution: This branch deals with the origin and successive transformationsof living organisms.The groups discussed above are the basic branches of Biology. Scientistsgradually started to utilize the knowledge of these branches for human welfare,and as a result applied branches of Biology were created. Agriculture,Medical science, Breeding etc. are some of the important applied branches ofBiology. Applied Biology also includes Forestry and Horticulture, Fishery,Pest Control. Animal Husbandry etc.There are numerous varieties of plants and animals on earth. Generally similarplants or animals are arranged in particular groups. Some special branches ofBiology have been created on the basis of different types of living things areunder discussion and research: for example. Phycology includes only membersof algae; fungi are treated in Mycology; Virology deals with viruses only;bacteria are considered in Bacteriology; Helminthology is based on study ofworms only; insects are discussed in Entomology.Each of the above mentioned divisions has been divided into subdivisions orbranches. It has been mentioned earlier that research in Biological fields hasgreatly extended now-a-days.Biology, as it appears today, was not the same the past 50 years ago. It wasbelieved that sweat-soaked warm clothing of men and some wheat, if kepttogether in a box for few days, rats would be produced. This wrong conceptabout the origin of life prevailed for a long time. Subsequently ideas aboutorigin of life have changed by the research works of various scientists. Modern

4Secondary BiologyBiology is the result of research and thinking of some great scientists. Thischapter introduces you with some of these scientists.Aristotle (384-322 B.C): The great Greek scientist, Aristotle is regarded as thefather of Zoology. He first established Zoology as a branch of Science.Aristotle was simultaneously a scientist, poet, thinker and philosopher. It is hewho first mentioned about the basic similarities in the structure of plants andanimals. He stayed in an island named Lesbos for five years continuously andmade research on animals. He wrote a book on animals and named it "Historiaanimalium" which is full of information and knowledge.Theophrastus (370-285 B.C.): Little amount of works of the Greekphilosopher Theophrastus is known to us. Of those available, nine volumes of"On the History of Plants" and six volumes of "On the causes of plants" areimportant. Theophrastus was the pupil of great philosopher Aristotle. Hedivided the plant community into four groups. For example: Trees shrubs,Undershrubs and Herbs. He is regarded as the Father of Botany.Al Biruni (973-1048): Known as an world famous scientist and educationist.Al Biruni was an Arabian citizen. His real name is Abu Raihan MohammadIbne Ahmed Al Biruni. He made contributions in different branches of science.He visited India during the reign of Sultan Mahmud of Ghazni and describedthe conditions prevailing in India in an attractive way.Ibne Sina (980-1037): He was a renowned Muslim philosopher and scientist.He had excellent skill in Chemistry, Medicine, Mathematics, Astronomy andLiterature. His full name is Abu Ali Hussain Ibne Abdullah Ibne Sina. Hecomposed more than hundred books on different subjects. Sixteen of whichwere written on Medicine. He had a fourteen volume compositions named AlKanun' on Medicine.