C11EMBiology(1).pdf

https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ The Coordination Committee formed by GR No. Abhyas - 2116/(Pra.Kra.43/16) SD - 4 Dated 25.4.2016 has given approval to prescribe this textbook in its meeting held on 20.06.2019 and it has been decided to implement it from academic year 2019-20. BIOLOGY Standard XI 2019 Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune. Download DIKSHA App on your smartphone. If you scan the Q.R.Code on this page of your textbook, you will be able to access full text. If you scan the Q.R.Code provided, you will be able to access audio-visual study material relevant to each lesson, provided as teaching and learning aids. https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ First Edition : © Maharashtra State Bureau of Textbook Production and Curriculum Research, Pune - 411 004. 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. Subject Committee: Dr. Chandrashekhar V. Murumkar, Illustrations and cover : (Chairman) Shri Vivekanand S. Patil Dr. Avinash Ade Coordinator : Dr. Naikare Shriram Maruti Shri. Rajiv Arun Patole Dr. Prakash Lohar Special Officer (Biology) Dr. Madhav Pralhad Bhilve Typesetting : DTP Section, Textbook Dr. Vishnu K. Vaze Bureau, Pune Dr. Kiran Randive Paper : 70 GSM Cream wove Shri. Rajiv Arun Patole Print Order : (Member Secretary) Printer : Study Group: Dr. Nilima Milind Mulgund Dr. Ravindra Kulkarni Dr. Sanjay Arun Prabhu Production : Dr. Khade Ravi Narayan Shri Sachchitanand Aphale Dr. Pawale Sandhya Rajendra Chief Production Officer Dr. Sucheta Mihir Waghaye Shri Liladhar Atram Dr. Shinkhede Milind Manohar Shri. Sandip Popatlal Chordiya Production Officer Shri. Pundalik Mallikarjun Sutar Shri. Amey Prakash Edlabadkar Shri. Prashant Pandurang Shirke Smt. Manjusha Suresh Kulkarni Smt. Revati Sunil Inamdar Publisher : Smt. Falguni Madlani Shri Vivek Uttam Gosavi Smt. Varsha Anandrao Patil Controller Smt. Shubhangi Shankar Kapare Maharashtra State Textbook Smt. Shweta Dilip Thakur Bureau, Prabhadevi, Mumbai - 400 025 Smt. Prachi Ravindra Sathe Chief Co-ordinator https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ The Constitution of India Preamble WE, THE PEOPLE OF INDIA, having solemnly resolved to constitute India into a SOVEREIGN SOCIALIST SECULAR DEMOCRATIC REPUBLIC and to secure to all its citizens: JUSTICE, social, economic and political; LIBERTY of thought, expression, belief, faith and worship; EQUALITY of status and of opportunity; and to promote among them all FRATERNITY assuring the dignity of the individual and the unity and integrity of the Nation; IN OUR CONSTITUENT ASSEMBLY this twenty-sixth day of November, 1949, do HEREBY ADOPT, ENACT AND GIVE TO OURSELVES THIS CONSTITUTION. https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ NATIONAL ANTHEM https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Preface Dear Students, We welcome you all to Std. XI. For the first time, you are being introduced to the subject of Biology as a separate discipline. You have already been acquainted with some of the concepts of Biological Sciences from Standard five onwards, especially in the subject of General Science up to standard Eight and Science and Technology for standard Nine and Ten. This textbook aims to create awareness about the biological sciences specially Botany, Zoology and allied aspects of biological sciences. The National Curriculum Framework (NCF) was formulated in 2005, followed by the State Curriculum Framework (SCF) in 2010. Based on the given these two frameworks, reconstruction of the curriculum and preparation of a revised syllabus has been undertaken which will be introduced from the academic year 2019-20. The textbook incorporating the revised syllabus has been prepared and designed by the Maharashtra State Bureau of Textbook Production and Curriculum Research, (Balbharati), Pune. The subject biology intends to give students understanding, and appreciation of the vast diversity of living beings, their special adaptations to their environments and evolutionary relationships. No compromise is made in any manner over the use of language in the Biology context, but at the same time, the textbook is presented in a simple language. In addition, relevant diagrams, graphs, tables used in the textbook will bring about more clarity in the understanding of various terminologies and biological concepts. All the illustrations are in colour form. This will enable students to understand various concepts of botany and zoology thoroughly and correlate this with their day-to-day practical life. The new syllabus focuses on the conceptual principles of overall life processes, its understanding, and application in day-to-day life and ability to solve different upcoming problems and issues like conservation; different diseases and remedies, the application of technology, etc. The general teaching-learning objectives of the revised syllabus are further determined based on the ‘principle of constructivism’ i.e. self-learning. The curriculum and syllabus confirms to the maxims of teaching such as moving from concrete to abstract, known to unknown and from part to whole. For the first time, in the syllabus of biology various independent activities have been introduced. These activities will not only help to understand the content knowledge but also provide scope for gaining relevant and additional application based knowledge on your own efforts. The detailed information of all concepts is also provided for the better understanding of the subject. Q. R. Code have been introduced for gaining the additional information, abstracts of chapters and practice questions/ activities. The efforts taken to prepare the textbook will not only enrich the meaningful learning experience of the students, but also benefit other stakeholders such as teachers, parents as well as those aspiring candidates preparing for the competitive examinations. We look forward to a positive response from the teachers and students. Our best wishes to all! (Dr. Sunil Magar) Director Place : Pune Maharashtra State Bureau of Textbook Date : 20 June 2019 Production and Curriculum Research, Bharatiya Saur : 30 Jyestha 1941 Pune, 411004 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ - For Teachers - Dear Teachers, Exercises provided after each unit are We are happy to introduce the revised prepared using different parameters like textbook of Biology for Std XI. This book is a observation, co-relation, critical thinking, sincere attempt to follow the maxims of teaching analytical reasoning etc. as well as develop a ‘constructive’ approach to Evaluation pattern should be based on enhance the quality of learning. The demand the above mentioned parameters. Equal for more activity based, experiential and weight age should be assigned to all the innovative learning opportunities is the need topics. Use different combinations of of the hour. The present curriculum has been questions. Stereotype questions should be restructured so as to bridge the credibility gap avoided. that exists between what is taught and what Use demonstration, discussion method for students learn from direct experience in the teaching. outside world. Guidelines provided below will ‘Can You Recall’ is the first main starting help to enrich the teaching-learning process point of lesson which helps for the and achieve the desired learning outcomes. introduction of topic. This will also helpful To begin with, get familiar with the for students regarding understanding the textbook yourself. content of lesson. The present book has been prepared for Use QR Code given in the textbook. constructive and activity-based teaching. Keep checking the QR Code for updated Teachers must skillfully plan and organize information. the activities provided in each chapter to ‘Internet My Friend’ is used for collecting develop interest as well as to stimulate the extra important information related to topic. thought process among the students. ‘Use Your Brain Power’ is used for the Always teach with proper planning. application level questions in different Use teaching aids as required for the proper lessons. understanding of the subject. ‘Do Your Self’, ‘Find Out’, ‘Observe Do not finish the chapter in short. and Discuss’ and ‘Try This’ are used for Follow the order of the chapters strictly as activity based learning. listed in the contents because the units are ‘Know the Scientist’ is used for the introduced in a graded manner to facilitate information of different scientist related to knowledge building. concepts in lesson. Facilitate peer learning as much as ‘Activity’ is used in lesson and exercise for possible by reorganizing the class structure better understanding and application of the frequently. content which studied. Teaching-learning interactions, processes Exercise is given at the end of lesson. and participations of all students are very In exercise different type of questions/ essential and so is your active guidance. activities are given. Ask questions based on previous Teacher should use their freedom to knowledge of different concepts of lesson. acquaint the students with flora and fauna Do not use the boxes titled ‘Do you of given region. know?’ for evaluation. However, teachers Remember that mathematical and must ensure that students read this extra statistical tools are also important to information. understand biology Information provided in boxes with the List of abbreviations are provided title ‘Can You Tell’, ‘Always Remember’ towards the end of the textbook for further should be considered for evaluation. clarification. Best wishes for a wonderful teaching experience and fruitful welcome! https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Competency Statements Standard XI Unit Competency Statements After studying the content in Textbook students will … Diversity in Analyse basic characteristics of living and non-living. living world Collect and analyse useful data by observing diversity of living organisms using different tools. Describe plants and animals in the surrounding on scientific basic and classify them using taxonomic hierarchy. Develop hobbies by watching and collecting the things (livings) and their conservation using databases. Classify different organisms based on cell structure, body organisation, mode of nutrition etc. Compare and analyse similarities and differences along with phylogeny amongst different groups of organisms. Recognize, analyse and compare structural similarities and differences and progressive evolutionary changes in different plants and animals. Cell structure Explain and draw the structure and functions of different cell organelles. and functions Elaborate the role of nucleus in heredity and controlling characters with structure of chromosome. Compare cell division process and know their role in life cycle of organisms. Analyse and specify different biomolecules of cell with their role in structural and functional aspect of cell. Structural Explain basic morphology of dominant plant group of this era i.e. Angiosperms. organization Compare morphological features of different plant parts in different plant families. in organisms Draw floral parts and floral diagram. Identify economic importance of Angiosperms with respect to fruit and seeds. Compare morphological feature of two major classes of Angiosperms. Explain different types of tissues in plants and reasons for growth viz. primary and secondary. Analyse basic differences in anatomy of different plants like dicot and monocots with respect to root, stem and leaf. Elaborate different animal tissues and their role. Explain and draw mechanisms of different physiological process like digestion and excretion. Review the contribution of different scientists in systematics and taxonomy. Plant Explain the scientific reasons behind the various physiological activities based physiology on relationship. Understand the relationship between chemical reactions of molecules in daily life and analyse them to solve various problems. Review the contribution made by different workers. Plan and implement programs about conservation of environment. Explain the importance of green energy and save energy in daily life. https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Animal Explain the need and importance of various physiological processes. Physiology Explain the structural modifications, observed in various living organisms to carry out various physiological processes. Observe and correlate the histological structure of various organs with their function. Comprehend mechanisms by which these physiological processes help maintain homeostasis. Create memory maps, flow charts to depict major events in these processes. Develop insight about connection between life style/habits and physiological disorders. Collect information about latest diagnostic tools and treatments for various physiological disorders. Critically analyse given situational data and come up with rationale of possible physiological disorders/suggest proper remedial measures. Perform various analytical tests to detect presence of certain components in food materials/waste products. Contents Sr. No. Name of the lesson Page No. 1. Living World 1-5 2. Systematics of Living Organisms 6 - 18 3. Kingdom Plantae 19 - 28 4. Kingdom Animalia 29 - 43 5. Cell Structure and Organization 44 - 58 6. Biomolecules 59 - 75 7. Cell Division 76 - 84 8. Plant Tissues and Anatomy 85 - 96 9. Morphology of Flowering Plants 97 - 115 10. Animal Tissue 116 - 126 11. Study of Animal Type : Cockroach 127 - 137 12. Photosynthesis 138 - 150 13. Respiration and Energy Transfer 151 - 160 14. Human Nutrition 161 - 173 15. Excretion and Osmoregulation 174 - 192 16. Skeleton and Movement 193 - 214 DISCLAIMER Note : All attempts have been made to contact copy right/s (©) but we have not heard from them. We will be pleased to acknowledge the copy right holder (s) in our next edition if we learn from them. https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 1. Living World Can you recall? There is immense diversity in living 1. What is the difference between living and organisms. Since time immemorial, variety of non-living things? organisms are living together on earth. In order 2. Enlist the characters of living organisms. to understand the interrelations between living 3. Whether all organism are similar? Justify and non-living as well as between two living your answer. beings or groups, systematic study of these is Planet earth is made up of abiotic and essential. This data is also important for various biotic components. The biotic components are industries and agriculture. Intensive laboratory obviously the living beings present around us. and field studies in order to identify and classify The question is why do we call them living and the organisms form strong basis for meaningful how do they differ from non-living? use of the collected data. If we need to study this 1.1 Basic principles of life : diversity, certain aids called taxonomical aids A. The living being once produced / born has can be used. These includes herbaria, botanical to survive. For survival, it needs energy and gardens, museums, biodiversity parks, etc. many chemical molecules. For energy, it has to perform metabolism. Metabolism is breaking Can you tell? 1. of molecules (catabolism) and making of new molecules (anabolism). 1. How can we study large number of B. From birth onwards, organisms show organisms at a glance? tendency of growth and development. This 2. Weather all organisms prepare their own growth is a well-orchestrated process. You food? might have observed sand mounds, boulders 3. Which feature can be considered as all grow, etc.This growth is not from within and inclusive characteristic of life? Why? hence these are not living beings. C. Growth and development are not the Think about it processes which have unlimited time span. At certain point of time, the molecules, organs, 1. Can metabolic reactions demonstrated in systems begin to loose their effective working a test tube (called ‘in vitro’ tests) be called and become old. This is ageing process of the living? body. 2. Now a days patients are declared ‘brain D. Life has to continue hence the organism dead’ and are on life support. They do not tries to produce a young one like itself. It show any sign of self-consciousness. Are is possible due to reproduction (asexual or they living or non - living? sexual). This ensures continuity of race. Mules, 1.2 Herbarium : sterile worker bees do not reproduce; yet are The word herbarium (plural-herbaria) living. Can we call reproduction as inclusive was coined by Pitton de Tournefort in the characteristic of life? book ‘Elemens’. The art of herbarium was E. As the body looses it's capacity to perform initiated by an Italian taxonomist Luca Ghini metabolism, the organism dies. (1490-1556). Herbaria are effective tools in F. Any living being responds to thermal, taxonomic studies. A herbarium is essentially chemical or biological changes in the a dried plant specimen that is pressed, treated surrounding. This is unique property of living and mounted on standard size sheet in order to beings. preserve it. 1 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Date, place of collection along with detailed classification and highlighting with its Know the scientists ecological peculiarities, characters of the plant are recorded on the same sheet. Local names In 1543, first and name of the collector may be added. This botanical garden of the information is given at lower right corner of world was established sheet and is called 'label'. by an Italian Prof. Luca Ghini (A. D. 1490-1556) at Pisa, Italy. Botanical garden at Kew in England is known for largest collection of more Prof. Luca Ghini than 30,000 specimens (preserved plants) and more than 7 million herbaria. Internet my friend Collect information about Prof. Fig. 1.1 Herbarium Almeida, Prof. V. N. Naik, Dr. A. V. Sathe, Dr. P. G. Patwardhan with reference to 1.3 Botanical Gardens : their taxonomic work and biodiversity Botanical gardens are the places where conservation. plants of different varieties collected from different parts of the world, are grown in a scientific and systematic in a in vivo manner. Plants are labeled. The label-board shows scientific as well as common name of the plant. Fig. 1.2 Botanical Garden : Kolkata 255 years old Banyan tree 2 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Conservation of Biodiversity : 1.5 Zoological Parks : Biodiversity is the degree of variation Zoological Park generally known as of life forms in an ecosystem. Biodiversity zoo, is a place of interest for common man. is essential to maintain ecological stability. In a zoo, wild animals are kept in captivity. The extent of complexity and density of They are protected and care is taken to provide biodiversity can be regarded as a measure conditions similar to their natural habitat. (ex- of health of an ecosystem. Population situ) In a zoo, a naturalist can study food habits explosion and over exploitation of resources and behavior of animals. has resulted in loss of biodiversity at an Flora, manuals, Monographs and alarming rate. Conservation involves Catalogue are some other tools of maintaining attempting to slow down, stop or even reverse biodiversity records. Flora is the plant the loss in the natural habitat of organism. life occurring in a particular area on time. This is known as in- situ conservation. Why A Monograph describes any one selected does the loss of biodiversity matter? For biological group where as manual provides many people, it is a simple moral or ethical information, keys about identification of species issue. We share our planet with a huge range found in a particular area. of other organisms and we have no right to harm them. Biodiversity helps to maintain stability in an ecosystem. Loss of one variety of organisms can affect entire ecosystem. 1.4 Museum : Museums are the places where, collections of preserved plant and animal specimens are kept. Plant and animal specimens may be preserved in formalin (10% to 40% formaledehyde) in transperent jars. Jars are labelled. Larger animals like birds and mammals are usually stuffed and preserved. This science is known as taxidermy. Specimens in dried form are also kept in museum. Fig. 1.4 Zoological Park We can even find systematic collections of shells, skeletons of animals, insect boxes in Can you tell? museums. 1. 1. What are the Thus, biological museums in essentials of a good herbarium? educational institutes are reference hubs of 2. Why should we visit botanical gardens, biodiversity studies. museums and zoo? 3. What is ' ex- situ' and ' in- situ' conservation? 1.6 Biodiversity parks : It is an ecological assemblage of species that form self-sustaining communities on degraded / barren landscape e.g. Late Uttamrao Patil biodiversity park Gureghar, Mahabaleshwar. This park is the best model for conservation of natural heritage in urban Fig. 1.3 Biological Museum landscape. 3 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Systematic classification of living 1.7 Key : organisms is helpful in understanding Key is taxonomical aid used for the interrelations. In order to understand classification of plants and animals. The keys interrelations between organisms and maintain are based on contrasting characters. One of the harmony on planet earth, study of biodiversity contrasting characters gets accepted and other is a must. rejected. The statement in key is called a lead. Normally keys are analytical in nature. Let us Know the scientists study about classification of living organisms in next chapter. Dr. S. P. Agharkar One of the leading botanists of India, Dr. Do you know ? S. P. Agharkar was born in November 1884 in When plants from any forest locality Malvan, Maharashtra. He are conserved on the name of holy place it is explored biodiversity of called as sacred grove these also considered Western Ghats where he as sacred natural sites by IUCN. came across a species of freshwater jellyfish, which was until then only known to be found in Africa. These findings were published in scientific journal Nature in 1912. Dr. Internet my friend Annandale, the Superintendent of the Indian 1. Collect information about botanical gar- Museum in Kolkata, helped Dr.Agharkar in dens, zoological parks and biodiversity hot his further endeavours to collect, preserve and spots in India. conduct microscopic examinations of animal 2. Collect information of endemic flora and and plant specimens. The institute ARI, Pune fauna of India. has been named after his name. Find out Human being is at key position in maintaining biodiversity of earth. Find out more information about the following. 1. Laws to protect and conserve biodiversity in India. 2. Environmental effects of ambitious projects like connecting rivers or connecting cities by constructing roads. 3. Did Bauxite mining in Western Ghats affect critically endangered species like – Black panther, different Ceropegia spp., E riocanlon spp.? 4 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Exercise 1. Choose correct option A. Which is not a property of living being? E. What do you understand from terms like a. Metabolism in situ and ex situ conservation? b. Decay 4. Write short notes c. Growth A. Role of human being in biodiversity d. Reproduction conservation. B. A particular plant is strictly seasonal plant. B. Importance of botanical garden. Which one of the following is best suited if it is to be studied in the laboratory? 5. How can you, as an individual, prevent the loss of Biodiversity? a. Herbarium b. Museum Practical / Project : c. Botanical garden 1. Make herbarium under the guidance of d. Flower exhibition your teacher. C. A group of students found two 2. Find out information about any one cockroaches in the classroom. They had sacred grove (devrai) in Maharashtra. a debate whether they are alive or dead. Which life property will help them to do so? a. Metabolism b. Growth c. Irritability d. Reproduction 2. Distinguish between botanical gardens, zoological park and biodiversity park with reference to characteristics 3. Answer the following questions A. Jijamata Udyan, the famous zoo in Mumbai has acclimatised humbolt penguins. Why should penguins be acclimatised when kept at a place away from their natural habitat? B. Riya found peculiar plant on her visit to Himachal Pradesh. What are the ways she can show it to her biology teacher and get information about it? C. At Andaman, authorities do not allow tourists to collect shells from beaches. Why it must be so? D. Why do we have green house in botanical gardens? 5 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 2. Systematics of Living Organisms Can you recall? Natural : It is the classification which is based on objectively significant rather than being What is five kingdom system of selected for convenience like artificial system classification? of classification e.g. Bentham and Hooker's system of classification. There is great diversity of organisms around us. Since time immemorial, we Phylogenetic : It is the classification based on humans have been exploiting this wealth for common evolutionary descent. e.g. Engler and our own benefit. During this process man prantles classification. tried to differentiate between and identify In the system of classification the the organisms. Eventually this evolved into terms like ‘taxa’ and ‘categories’ are often a branch of biology known as systematics or used. Each category is referred to as a unit of classification. The methods of classification classification. In fact, it represents a rank and dates back to ancient time when Indian, Greek is commonly termed as taxon. and Roman philosophers have contributed their might to systematise science. Archaea 2.1 Systematics : Bacteria Eukaryota ‘‘Systematics is the study of kinds and diversity of organisms and their comparative and evolutionary relationship’’(G. Simpson, 1961). Common ancestor Taxonomy : Fig 2.1 Phylogenetic descent Taxonomy means classification following certain rules or principles. Word Taxonomy comes from two Greek words, 2.3 Three domains of life : taxis – meaning arrangement and nomous It is believed that the life originated on meaning law or rule. The term taxonomy was earth in its very simple form. Constant struggle first introduced by A. P. de Candolle (Swiss of the early living beings gave rise to more and Botanist) [1778-1841]. more perfect forms of life. This struggle and progress is evolution which led to formation of 2.2 Classification : diverse life forms. Carl Woese in 1990 proposed It is the arrangement of organisms three domains of life to classify life forms. They or groups of organisms in distinct categories are Archaea, Bacteria and Eukarya. Domain is in accordance with a particular and well an unit larger than Kingdom in the system of established plan. This classification is based classification. on similarities and dissimilarities among the Bacteria and Archaea both have organisms. prokaryotic cells where as Eukarya have Artificial : eukaryotic cell. All the three domains have It is the classification that is based on very unique ribosomal RNA (rRNA). Archaea few easily observable and non-evolutionary are known for their survival in very extreme featurs such as habit, colour, form, etc.; often conditions like high tempreature, salinity, irrespective of their affinity (relationship) acidic conditions, etc. Bacteria, though are with other organisms. e.g. Linnaeus system of prokaryotes differ from Archaea in structure of classification. cell wall. 6 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 2.4 Chemotaxonomy : It helps to study newly identified It is method of biological classification species as well as understanding ecological based on similarities and differences in and evolutionary relationships between living structure of certain compounds present among beings. The process of DNA barcoding includes the organisms being classified. In short, it is the two basic steps: (a) collecting DNA barcode classification based on chemical constituents data of known species and (b) matching the of organisms. e.g. Archaea cell wall is without barcode sequence of the unknown sample peptidoglycan and that of Prokarya is with against the barcode library for identification. peptidoglycan. Among Eukarya, fungi have DNA barcoding has many applications. A chitinous cell wall while plants have cellulosic few to mention are, protection of endangered cell wall. species, preservation of natural resources, pest control in agriculture, identifying disease 2.5 Numerical taxonomy : vectors, authentication of natural health The system is based on quantification products and identification of medicinal plants. of characters and develops an algorithm for classification. The basic aim of this taxonomy was to create a taxonomy using numeric Can you tell? algorithms like cluster analysis rather than using subjective evaluation of their propertise. 1. Which characters of organisms are visible This system was first proposed by Sokel and characters? Sneath in 1963. 2. Name the recent approaches in taxonomy. 3. What is DNA barcoding? 2.6 Cladogram : 4. What is evolution? It is a typical branching pattern. As 5. Enlist uses of taxonomy. shown on previous page, a diagram of three domains of life is a cladogram. It represents 2.9 Taxonomic Categories : a hypothetical relationship denoting a Classification is not a single step comparison of organisms and their common process but involves hierarchy of steps in which ancestors. each step represents a rank or category. Since 2.7 Phylogeny : the category is a part of overall taxonomic It is evolutionary relationship of arrangement it is called taxonomic category organism. It is an important tool in classification and all categories together constitute the as it takes into account not merely the taxonomic hierarchy. Kingdom, division, class, morphological status but also the relationship order, family, genus, species are the categories of one group of organism with other groups in hirarchial sequence. These are compulsory of life. The system helps to understand the categories. Besides, there are some facultative evolution and also focuses on the similarities categories like sub-order, sub-family, etc. to be of their metabolic functioning. Woese’s three used as per need. domain concept as well as Whittakar’s five 2.10 Taxonomic Hierarchy : kingdom system are very good examples of Taxon : A taxon is the taxonomic group phylogenetic relationship. of any rank in the system of classification 2.8 DNA barcoding : (H.J. Lam 1948) e.g. in plant kingdom each DNA barcoding, is a new method for one of the following such as Angiosperms, the identification of any species based on its Dicotyledonae, Polypetalae, Malvaceae DNA sequence from a tiny tissue sample of the represents a taxonomic group i.e. a taxon. organism under study. 7 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Category Taxon Taxon Cohort / Order : It is taxonomic rank used in the classification of organisms and Kingdom Plantae Animalia recognised by nomenclature codes. An order Division/Phylum Angiospermae Chordata is a group of closely related families showing Class Dicotyledonae Reptilia definite affinities. Order thus is a step above Sub-class Polypetalae Diapsida family in taxonomic hierarchy. Members Series Thalamiflorae - belonging to same order but different families Order Malvales Squamata may show very few dis similarities. e.g. family Family Malvaceae Elapidae - Papavaraceae, Brassicaceae, Capparidaceae, Genus H ibiscus N aj a etc with parietal plancentation are grouped Species rosa- sinensis naj a in order Parietales. Families of dogs and cats though are different, they belong to same order Table 2.2 Classification of China-rose and Carnivora. Cobra Class : The class is the distinct 2.11 Units of Classification : taxonomic rank of biological classification Species : Species is the principal having its own distinctive name. A group of natural taxonomic unit, ranking below a genus higher taxonomic rank than order. Class is the and denoted by latin binomial (considered as assemblage of closely allied orders. Orders the basic) unit of classification. It is a group Carnivora and order Primates belong to class of organisms that can interbreed under natural Mammalia. Thus monkeys, gorillas, gibbons condition to produce fertile offspring. It was (Primates) and dogs, cats, tigers (Carnivora) thought to be an indivisible, stable and static belong to same class. unit. However in the modern taxonomy, sub- Division / Phylom : The division is division of species such as sub-species, varities a category composed of related classes e.g. and populations are seen and given more division. Angiospermae includes two classes importance. - Dicotyledonae and Monocotyledonae (In Genus : Genus is a taxonomic rank animal classification division is a sub-unit of or category larger than species used in the Category / Phylum). biological classification of living and fossil Sub-kingdom : Different divisions organisms. Genus is a group of species bearing having some similarities form sub-kingdom. close resemblance to one another in their e.g. The divisions Angiospermae and morphological characters but they do not Gymnospermae will the sub-kingdom interbreed. e.g. Tiger, Leopard, Lion all three Phanerogams or Spermatophyta. belong to same genus Panthera. They have Kingdom : It is the highest taxonomic common characters yet are different from each category composed of different sub- other because their genus is same but species is kingdoms. e.g. sub-kingdom Phanerogams different. Another example is genus Solanum. and Cryptogams form the Plant kingdom or Brinjal and potato both belong to this genus. Plantae which includes all the plants while all animals are included in kindom Animalia. Family : It is one of the major hierarchial taxonomic rank. A family represents The taxonomic categories we have a group of closely related genera. e.g. genera considered so far are broad categories. like H ibiscus, Gossypium, Sida, Bombax are Scientists have added sub-categories to these included in same family Malvaceae. Cat also in order to place organisms in more scientific belongs to family of leopards, tigers and lions, manner. You will observe that as we go higher family Felidae but dog belongs to different in taxonomical ladder, number of common family Canidae. characters go on decreasing. 8 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ If we are comparing two organisms Before 2011, the code which was set up that are related to each other only at division or to confirm the scientific names was ICBN phylum level, their classification may become means International Code of Botanical difficult. Nomenclature. Recently XIX International Botanical Congress (IBC) was held in Can you tell? Shenzhen, China in July 2017. This code is also called "Shenzhen code", so the old 1. Why horse and ass are considered to be code ICBN has been changed to ICNAFP two different species or animals? means "International Code of Nomenclature 2. Make a flow chart showing taxonomic for Algae, Fungi and Plants". This code was hierarchy. published on 26th June 2018. 2.12 Nomenclature : According to this system the scientific Any object that becomes known to name of sunflower is H elianthus annus. In the human intelligence must possess a name. It above H elianthus indicates name of the genus may not be possible or convenient to describe it (generic name) and second word annus denotes in order to communicate ideas about it. The art name of the species. of naming the objects is in fact, a science called The Binomial Nomenclature system follows nomenclature. All living organisms are known certain rules. by a particular name. y Name of organism is composed of two 1. Vernacular / Local names / Common Latin / Greek words. names: Widely distributed organisms have y Generic name is a simple noun. It should a large number of common names. Pansy come first and begin with capital letter. (V iola tricolor L. ) grown in most European y Specific name is the descriptive adjective and American gardens has about 50 common which should come later and begin with English names. In a multilingual country like small letter. India, almost all useful plants have local names y Scientific names must be underlined which differ from language to language and separately if hand written and must be even from dialect to dialect. As in Ayurveda, printed in italics. mango (Mangif era indica L. ) is known by over y The generic and specific name should not 50 different names, all in the Sanskrit language. have less than three letters and more than Hence the common names obviously have thirteen letters. limited usage and for universal applications, a y Usually the name of the author who names unique name for a particular individual is very a plant or animal is also written in full or much essential. abbreviated form after scientific name. e.g. 2. Scientific Names : To overcome the Mangif era indica L. Where L stands for difficulties raised by common names, scientists Linnaeus. have given scientific names to all the known organisms. These are systematic, thus provide Internet my friend means for international communication. 1. Collect the information about most Initially the polynomial system was used recent system of classification of living but Carl Linnaeus used binomial system of organisms and Kingdom System of nomenclature. He introduced this system in his Classification. e.g. Search for APG book ‘‘Species Plantarum’’ published in 1753. system of classification for Plants. International Code of Botanical Nomenclature 2. Collect the information about (ICBN) has been set up to confirm the scientific classification systems for all types of names. organisms. 9 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Membrane bound organelles e.g. Know the scientists mitochondria, chloroplast, endoplasmic reticulum are absent. Ribosomes are smaller in Carl Linnaeus classified living size (70S) than in eukaryotic cells. The mode of organisms in two kingdoms based on mode reproduction in monera is asexual or with the of nutrition, whether they are migratory, help of binary fission or budding. Very rarely, sedentary, etc. But this broad classification sexual reproduction is by conjugation method. as Kingdom Plantae and Kingdom Animalia Morphologicaly, bacteria are was found inadequate. It could not classify categorised into four groups, the spherical- the organisms that show characters of both the Coccus, the rod-shaped bacillus, the comma or Kingdoms for ex. Bacteria, Fungi, Euglena kidney shaped- vibrio and the spiral- spirillum. etc. Hence to avoid confusion scientist R.H. On the basis of evolution, bacteria can Whittaker (1969) proposed Five Kingdom be classified as Archaebacteria and Eubacteria. system of classification. This system shows the Phylogenetic relationship between the a. Archebacteria : organisms. The five kingdoms are. These are differentiated from other bacteria on the basis of their different cellular features. These bacteria are mostly found 1. Kingdom Monera in the extreme environments; hence termed extremophiles. They are found in a variety 2. Kingdom Protista of places from volcanic craters to salty lakes 3. Kingdom Plantae and hot springs. Their ability to withstand such 4. Kingdom Fungi hostile environment speaks of their capacity to survive in very severe conditions. Bacteria 5. Kingdom Animalia that can withstand high salinities are called R. H. Whittaker halophiles while those that withstand extreme temperature are known as thermophiles. A very common example is of methanogenic 2.13 Salient features of Five Kingdoms : bacteria found in gut of ruminants (cows and buffaloes). These bacteria help in production of 1. Kingdom Monera : methane in biogas plants. It contains unicellular organisms with prokaryotic cellular organization. Monera includes unicellular prokaryotic organisms. Coccus Coccobacillus Vibrio Bacillus These are omnipresent. They are found in all types of environment which are not generally inhabited by other living beings. Few are Spirillum Spirochete photoautotrophs or chemoautotrophs; but majority are heterotrophic in nature. These Fig. 2.3 Different shapes of bacterial cells organisms do not have well defined nucleus. b. Eubacteria : DNA exists as a simple double stranded These are commonly referred as true circular single chromosome called as nucleoid. bacteria. They have cell wall of peptidoglycan. Smaller circular molecules of DNA as extra- They are found as autotrophs and heterotrophs. chromosomal genetic elements called plasmids The autotrophs can be photosynthetic like are often present. Cell wall is made up of Chlorobium (Green sulphur bacteria) and peptidoglycan (also called murein) which is a Chromatium or chemosynthetic like sulphur polymer of sugars and amino acids. bacteria. 10 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ These are mostly multicellular 2. Kingdom Protista : filamentous forms living in fresh water. The This group includes all the unicellular body is covered by mucilagenous sheath. but eukaryotic organisms. These organisms The genetic material is typical prokaryotic. show link with all eukaryotic Kingdoms like Chl-a, Chl-b, carotenes and xanthothylls are Plantae, Fungi and Animalia. the photosynthetic pigments. Filaments show a. Plant like protista : heterocyst which helps in nitrogen fixation. They are also termed Chrysophytes. Heterotrophs are the most abundant. They are commonly termed phyto-planktons. Most of them are decomposers and known They are microscopic and mostly photosynthetic for breaking down large molecules in simple and are major producers in oceans. Most of molecules or minerals. They can be anaerobes them are referred to as diatoms as the have helping in curdling of milk (L actobacilli), body wall made up of two soap-box like fitting fixation of nitrogen (Az otobacter), antibiotic silica covers. “Diatomaceous earth" is nothing production (Streptomyces), composting and but these shells left behind for so many years. degrading oil. But the story doesn’t end here, Diatomaceous earth is granular hence finds use some of them are pathogens i.e. causing disease in polishing and filtration. (typhoid, cholera, tuberculosis, tetanus). Heterocyst Mucilagenous sheath Fig. 2.5 Diatoms Fig. 2.4 Cynaobacterium (N ostoc) b. Animal like Protista :- They are also termed protozoans. They lack cell wall. They are heterotrophs. They are believed to be primitive Can you tell? animal forms. Amoeboid protozoans have 1. What are salient features of Monera? pseudopodia as locomotory organs. Amoeba is 2. What will be the shape of a bacillus and free living form but Entamoeba is endoparasite coccus type of bacteria? and causes amoebic dysentery. Flagellated 3. Write a note on useful and harmful protozoans have flagella as locomotory bacteria. organ. Trypanosoma is a common flagellated pathogen which causes sleeping sickness. Mycoplasma : Paramoecium is a cilliate protozoan These are smallest of the living forms. having cilia for locomotion. In Paramoecium, They do not have cell wall. Many forms are gullet (a cavity) opens on the cell surface. pathogenic. They are found resistant to Plasmodium is a sporozoan protozoa. It causes common antibiotics due to absence of cell wall. malaria. It forms spores in one of its life stage. 11 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Contractile e. Euglenoids :- They lack cell wall but have a Micronucleus vacuole tough covering of proteinaceous pellicle. Macronucleus They possess two flagella, one short Food and other long. They behave as heterotrophs in Vacuoles absence of light but possess pigments, similar Cilia to that of higher plants, for photosynthesis. Cytopyge Gullet Lysosomes Oral Groove Nucleus Nucleolus Trichocyst Mitochondria Fig. 2.6 Param oeciu m Chloroplasts Flagellum Stored c. Dinoflagellates :- These are aquatic (mostly carbohydrate marine) and photosynthetic. The cell wall Endoplasmic is made up of cellulosic stiff plates. They reticulum Photoreceptor Golgi apparatus possess a pair of flagella. They have a wide Contractile vacuole range photosynthetic pigments, which can be yellow, green, brown, blue and red. Gonyaulax is dinoflagellate that is responsible for famous Fig. 2.8 Eu g l ena ‘red tide’. It makes even sea appear red. 3. Kingdom Plantae: Apical horn The kingdom is dominated by Flagellar pore (s) autotrophs. It also includes some semi- Epitheca autotrophic members, the insectivorous plants like Venus fly trap, pitcher plant, bladderwort, Cingulum as well as heterotrophic parasitic members like Cuscuta. Members of this kingdom Hypotheca Flagella Plates are multicellular, having eukaryotic cells containing chlorophyll. Cells have cell wall Sulcus mostly made up of cellulose. Plants exhibit Ventral view alternation of generation i.e., life cycle has two distinct phases. Kingdom Plantae is divided into two major groups Cryptogamae / Cryptogams and Phanerogamae / Phanerogams. Anatomical horns We will study this kingdom in detail in Dorsal view next chapter. Fig. 2.7 G ony au l ax 4. Kingdom Fungi : These are eukaryotic heterotrophs showing extracellular digestion. d. Fungi like protista :- They are commonly They are found in warm and humid places. They from the group Myxomycetes. These are have simple body which may be unicellular or saprophytic organisms found on decaying made up of long thread like structures called leaves. Their cells aggregate to form a large hyphae. Large fungi such as mushrooms have cell mass called plasmodium (not a malaria a compact mass of cells. Unicellular organisms parasite). The spores produced by plasmodium have a protoplast with many nuclei. e.g. are very tough and survive even very harsh Rhiz opus, Saccharomyces (Yeast-unicellular conditions. fungus). 12 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Filamentous fungi consist of a body b. Ascomycetes : called mycellium in which hyphae are present. These are called as sac-fungi. These The hyphae may be with septa or without fungi are mostly multicellular. Rarely septa. They may be uni or multinucleate. The unicellular varieties include yeast. The hyphae non-septate multinucleate hyphae are called are branched and septate. Sac fungi can be coenocytic hyphae. The cell wall in fungi is decomposers, parasites or coprophilous (grow composed of chitin, a polysaccharide or fungal on dung). Morels and truffles are varieties cellulose. The fungi exhibit hetrotrophic mode of sac fungi that are consumed as delicacies. of nutrition. Mostly they are saprophytic, some N eurospora is useful in genetic and biochemical are parasitic or predators. They reproduce assays. sexually as well as asexually. Asexual Ex. Aspergillus, Penicillium, Claviceps, reproduction takes place by fragmentation, N eurospora, Saccharomyces. fission and budding. Some fungi are symbiotic; either live with algae as lichens or as mycorrhiza in association with roots of higher plants. They are useful as well as harmful. Mushrooms are consumed as food, yeast is used in bakery and breweries. Penicillium, a fungus, is well known for antibiotic production. Harmful fungi cause diseases in plants and animals. e.g. Puccinia. The fungi are further classified on the basis of their structure, mode of spore formation Fig. 2.10 A spe rgi l l u s and fruiting bodies as follows- a. Phycomycetes : c. Basidiomycetes : These are commonly called algal fungi. These are commonly called club fungi. Mycelium is made up of aseptate coenocytic They have branched, septate hyphae. e.g. hyphae. They commonly grow in moist and Agaricus (mushrooms), Ganoderma (bracket damp habitats, on decaying organic matter as fungi), U stilago (smuts), Puccinia (rusts), etc. well as in aquatic habitats or as parasites on plants. e.g. Mucor, Rhiz opus (bread mould), Albugo (parasitic fungus on mustard). Sporangium Sporangiophore Hypha Fig. 2.11 Mushroom d. Deuteromycetes : These are called imperfect fungi, which Fig. 2.9 M u cor are known to reproduce only asexually. e.g. Alternaria, Colletotrichum. 13 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 2.14 Acellular organisms : a. Viruses : Viruses were named so by Louis Pasteur; considering the meaning, Venom or poison. These obligate parasites were given the name 'virus' by M. J. Beijernek, after observation that they were able to migrate in an agar gel. Thus, being and infectious soluble agent, he called the filtrate as 'contagium vivum fluidum'. It was scientist Stanley who Fig. 2.12 A l ternaria demonstrated that viruses are inert outside the host cell and can be crystallised. They are Can you tell? made up of proteins. Viruses lack their own cell machinery. 1. Write a note on economic importance of They have protein coat (capsid) around nucleic fungi. acid strand, thus considered to be acellular 2. Why are fungi considered as heterotrophic organisms. Viruses are inactive outside a host organisms? cell; but once they enter their specific host cell, 3. What are coenocytic hyphae? they take charge of cellular machinery of host 4. Classify fungi into their types. cell and duplicate themselves. Viruses thus can 5. Kingdom Animalia : Members of this be called infectious nucleoprotein particles. kingdom are heterotrophs; adapted to holozoic Types of viruses : nutrition. Most of them have capacity of As per genetic material, viruses are locomotion. They are multicellular eukaryotes grouped as DNA or RNA viruses. where cells lack chlorophyll as well as cell wall. Growth is determinate (follow definite pattern). Do you know ? In chapter four, we will study Viruses have either DNA or RNA as about Kingdom- Animalia and its further their genetic material but never DNA as well classification. as RNA. Can you tell? 1. Differentiate between Plantae and Animalia. 2. How are fungi different from plants? 3. Have you seen any diseased plant in your farm? Hollow core o Do you know ? Radius 40 A RNA New variety of Banana seedlings Capsomeres produced by tissue culture technique like ‘Shrimanti’, Basarai, G-9 are virus free RNA varieties. Viruses, Viroids are groups of acellular o organisms that are not included in Whitaker’s Pitch 23 A Five Kingdom classification. Fig. 2.13 Tobacco mosaic virus (TMV) 14 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Protein coat called capsid is made up of c. Lichens : Lichen is co-existence of algae smaller units, the capsomeres. Capsomeres are and fungi for mutual benefit. Algal member, arranged in polyhedral or helical forms. Capsid the phycobiont as it is called, mostly belongs protects genetic material. to cyanobacteria (blue-green algae) or green The genetic material in viruses is either algae. Fungal member is called mycobiont. single-stranded RNA or single or double- They are excellent example of symbiosis. The stranded RNA or double-stranded DNA. algal component of lichens provides food to Viruses that infect bacterial cells are called fungal part while fungus provides shelter to bacteriophages which normally have double- alga and also absorbed water and minerals to stranded DNA. alga. The association is intense and it is difficult to identify them as separate living beings. Though found in extreme environments Head like snow clad poles, lichens are sensitive Collar Core to pollution. They are not found in polluted Sheath regions, hence are considered as pollution indicators. Lichens also play important role in soil formation by using specific acid Baseplate productions. Tail fibers Fig. 2.14 Bacteriophage Viruses cause disorders like leaf curling, yellowing, mosaic formation etc. in plants. You have heard of foot and mouth disease in animals Fig. 2.15 Lichens or swine flu which are viral diseases. Small pox, mumps, herpes to common cold, viruses are the causative agents of many diseases in Can you tell? humans. The list includes AIDS too! 1. Why are viruses called infectious b. Viroids : Potato spindle tuber disease was nucleoproteins? found to be caused by single stranded RNA 2. Describe genetic material in plant which lacks protein coat. T. O. Diener in 1971 and animal viruses as well as in reported that this is low molecular weight bacteriophages. RNA and smaller in size than viruses. These 3. Differentiate between viruses and viroids. infectious RNA strands are called viroids. o Internet my friend Prions : In modern medicine, certain infectious neurological diseases were found to be transmitted by abnormally folded proteins. These proteins are called prions. The word prion comes from ‘proteinaceous infectious particle’. e.g. mad cow disease in cattle, Jacob's disease in human. Find more information about prions. 15 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Observe and Discuss Complete the following table on the basis of previous knowledge. Characters Monera Protista Fungi Plantae Animalia Cell type Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic Cell wall Present in some Present............... -------- organisms............... (cellulose) Nuclear Absent Present Present................ Present membrane Body Unicellular................. Multicellular/ Tissue /organ Tissue/ organization loose tissue organ /system Mode of Autotrophic Autotrophic nutrition............. Photosynthetic................... (Photosynthetic) -------- Heterotrophic Ecological Decomposers.................... Decomposers................. Consumers role Do Yourself Complete the following table through collecting information about sunflower, tiger with characteristic features. Category Taxon Characteristics Kingdom Sunflower Category Taxon Characteristics Kingdom Tiger 16 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Exercise 1. Choose correct option 5. Draw neat labelled diagrams A. Which of the following shows single A. Paramoecium stranded RNA and lacks protein coat? B. Euglena a. Bacteriophage b. Plant virus C. TMV c. Viroid d. Animal virus 6. Complete chart and explain in your word B. Causative agent of red tide is _____________. a. Dinoflagellate b. Euglenoid c. Chrysophyte d. Lichen Types of Viruses Animals C. Select odd one out for Heterotrophic bacteria. a. Nitrogen fixing bacteria b. Lactobacilli c. Methanogens 7. Identify the following diagrams, label d. Antibiotic production them and write detail information in D. Paramoecium : Ciliated Protist your words Plasmodium : ____________ a. Amoeboid protozoan b. Ciliophora c. Flagellate protozoan d. Sporozoan 2. Answer the following A. What are the salient features of monera? B. What will be the shape of bacillus and coccus type of bacteria? C. Why is binomial nomenclature important? A 3. Write short notes A. Useful and harmful bacteria. B. Five Kingdom system C. Useful Fungi 4. Complete tree diagram in detail Fungi B Protista 17 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 8. The scientific name of sunflower is given below. Identify the correctly written name. A. H elianthus annus B. H elianthus Annus 9. Match the following. Kingdom Examples i. Monera a. Lichen ii. Protista b. Cyanobacteria C iii. Plantae c. Rhiz opus iv. Fungi d. Spirogyra 10. Complete the following A. Plant-like Protista - B. - Entamoeba Practical / Project : 1. Make a group of students. Observe D living organisms in your school/college campus and try to write their characters with respect to habit, habitat, mode of nutrition, growth- determinate or indeterminate, type of reproduction - vegetative reproduction - asexual reproduction - Sexual reproduction. With the help of similarity and dissimilarity, try to classify organisms into different categories. Similar work should implement for animal group. 2. Find out types of lichens and its economic importance. E F 18 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ 3. Kingdom Plantae Can you recall? Observe and Discuss 1. Why do we call as plants producers on Collect different water samples of land ? fresh water. Mount them on a glass slide and 2. What are differences between observe under a compound microscope. Try sub-kingdoms Cryptogamae and to identify the organisms which are visible Phanerogamae? under it. 3. Differentiate between Thallophytes and Bryophytes. 3.2 Salient features of major plant 4. Give any two examples of Pteridophyta. groups under Cryptogams : 3.1 Kingdom plantae : A. Division : Thallophyta - Members In earlier chapter, we have studied are mostly aquatic, few grow on other plants different aspects of classification. as epiphytes. Some grow symbiotically and Kingdom Plantae is further classified epizoic i.e. growing or living non-parasitically on the basis of characteristics like absence on the exterior of living organisms. Aquatic or presence of seeds, vascular tissues, algae grow in marine or fresh water. Most of differentiation of plant body, etc. them are free living while some are symbiotic. Phanerogams are commonly called seed Plant body is thalloid i.e. undifferentiated producing plants. They produce special into root, stem and leaves. They may be small, reproductive structures that are visible unicellular, microscopic like Chlorella (non- (Phaneros – visible) motile), Chlamydomonas (motile). They can Cryptogams are spore producing plants be multicellular, unbranched, filamentous like and do not produce seeds and flowers. Spirogyra or branched, filamentous like Chara. They reproduce sexually by gametes but Sargassum, a huge macroscopic sea weed sex organs are concealed (kryptos : hidden, which measures more than 60 meters in length gamos : marriage). is also an alga. Classification of Kingdom Plantae is represented as follows : Kingdom- Plantae Cryptogams Phanerogams Non-Vascular Plants Vascular Plants Vascular Plants Thallophyta Bryophyta Pteridophyta Gymnosperms Angiosperms Dicotyledonae Monocotyledonae Chart 3.1 Classification of Kingdom Plantae 19 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ The algal cell wall contains either Pyrenoids are located on Chloroplast. polysacchrides like cellulose / glucose or a Members are rich in protein, so used as food; verity of proteins or both. Reserve food is in the used even by space travellers. e.g. Chlorella. form of starch and its other forms. Reprocuction Chlamydomonas, Spirogyra, Chara, V olvox, takes place by vegetative asexual and sexual U lothrix etc. way. The life cycle shows phenomenon of alternation of generation, dominant haploid and Internet my friend reduced diploid phases. Algae are classified as per its pigments like chlorophyll, xanthophylls 1. Make a list of green algae with their and phycobilin. characteristic shape of chloroplast. 2. Enlist the forms of filamentous algae. a. Chlorophyceae (green algae) : 3. Write different pigments found algae. These are mostly fresh water (few brackish water and marine). b. Phaeophyceae (Brown algae) : Plant body is unicellular, colonial, filamentous. Plant body : Mostly marine, rarely Cell wall contains cellulose. fresh water. Simple branched / filamentous (e.g. Chloroplasts are of various shapes Ectocarpus) / profusely branched (Petalonia). like discoid, plate-like, reticulate, cup-shaped, Cell wall has cellulose, fucans ribbon-shaped or spiral with chlorophyll a and and algin. Photosynthetic pigments like b. The stored food is in the form of starch. chlorophyll-a, -c and fucoxanthin are present. Mannitol, laminarin and starch are stored Chloroplast food materials. Body is usually differentiated Nucleus into holdfast, stalk called stipe and leaf-like C hl am y dom onas photosynthetic organ called frond. Many species of marine algae are used as food. e.g. Pyrenoid (starch storage) Porphyra, L aminaria, Sargassum. Some species are used for production of hydrocolloids. e.g. Mitochondria (Amino acid synthesis) Ectocarpus, F ucus, etc. Oogonium (contains eggs) Lamina C hara Antheridium Stipe (contains sperm) Gametophyte Holdfast Mucilage Cell membrane S argas su m Cell wall Cytoplasm L am inaria S pi rogy ra Cytoplasm Nucleus Pyrenoid F u cu s strand Chloroplast Vacuole Fig. 3.2 Chlorophyceae Fig. 3.3 Phaeophyceae 20 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ c. Rhodophyceae (Red algae) : Plant body These are found in marine Can you tell? as well as fresh water on the surface, deep sea 1. What are the three major groups of and brakish water. Plant body is thalloid. Cells Cryptogams ? contain chlorophyll a, d and phycoerythrin. 2. Name the accessory pigments of algae. Cell wall is made up of cellulose and pectin 3. Give salient features of algae. glued with other carbohydrates. Stored food is Differentiate between Chlorophyceae and in the form of Floridean starch. Commercially Phaeophyceae. important agar-agar which is used as solidifying 4. Enlist examples of Chlorophyceae and agent in tissue culture medium is obtained from Rhodophyceae. red algae. e.g. Chondrus, Batrachospermum Porphyra, Gelidium , Gracillaria, Polysiphonia, Observe and Discuss etc. You may have seen F unaria plant in rainy season. Why is it called amphibious plant? B atrachospe rm u m B. Bryophyta (Bryon : moss ; phyton : plant) Bryophytes are mostly terrestrial plants. They are found in moist shady places. But they need water for fertilization and completion of their life cycle. Hence they G racil l aria are called ‘amphibious plants’. They include approximately 960 genera and about 25,000 species. Life cycle of Bryophytes shows sporophytic and gametophytic stages. Vegetative plant body is thalloid or leafy which represents gametophytic generation. Spore Pol y siph onia producing capsule represents sporophytic generation. Bryophytes have root-like structures called rhizoids. Rhizoids are unicellular in liverworts while multicellular in mosses. Fig. 3.4 Rhodophyceae Rhizoids absorb water and minerals and also Internet my friend help in fixation of thallus on the substratum. 1. Economic importance of algae. Bryophytes are divided into two groups : 2. Role of algae in environment. liverworts and mosses. 3. Different forms of green, red, brown and a. Liverworts (Hepaticeae) : blue green algae. These are lower members of Bryophyta. These are primitive group of Bryophytes. Gametophyte possesses flat plant body called Do you know ? thallus. The thallus is green, dorsiventral, Brown algae- kelps may grow up prostrate with unicellular rhizoids. e.g. Riccia, to 100 meters in height. Find out more Marchantia. information about Sargasso sea. 21 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Hornworts (Anthocerotae) - These member Economic importance - possess flattened thallus. The thallus produces Some mosses provide food for horny structures which are called sporophytes herbivorous mammals, birds, etc. Species of hence the name hornworts. e.g. Anthoceros. Sphagnum, a moss; provides peat used as fuel. b. Mosses (Musci) : Mosses are also used as packing material for These are advanced members of transport of living materials because they Bryophyta which possess erect plant body. have significant water holding capacity. Just Gametophytic phase of the life cycle like lichens, mosses are the first living beings includes two stages namely; protonema stage to grow on rocks. They decompose rocks to and leafy stage. The protonema is prostrate form soil and make them suitable for growth green, branched and filamentous (it is also of higher plants. Dense layers of mosses help called juvenile gametophyte). It bears many in prevention of soil erosion, thus act as soil buds. Leafy stage is produced from each binders. bud. Thus protonema helps in the vegetative C. Pteridophyta propagation. The leafy stage has erect, slender (Pteron : feather, phyton : plant) stem like (Cauloid) main axis bearing spiral Evolutionarily, Pteridophytes are the leaf like structures (Phylloid). It is fixed in soil first vascular and true land plants. Hence by multicellular branched rhizoids. This stage considered as the first successful terrestrial bears sex organs. Vegetative reproduction plants with true roots, stem and leaves. These takes place by fragmentation and budding in plants have a primitive conducting system and secondary protonema. they are the only Cryptogams with vascular e.g. F unaria, P olytrichum, Sphagnum , etc. tissues. The late Paleozoic era is regarded as the age of Pteridophytes. The group has about 400 genera and 11,000 species. The plants consist of pinnate (feather like) leaves. Leaves may be small called microphylls (e.g. Selaginella) or large called macrophylls (e.g. N ephrolepis / fern). Blade R iccia (Liverworts) A nthoceros Frond Capsule Sporophyte Seta Rhizome foot Roots Back side Front side Gametophyte Main axis F u naria Rhizoids Fig. 3.5 Mosses Fig. 3.6 N eph rol epi s (Fern) 22 https://www.ncertbooks.guru/ https://www.ncertbooks.guru/ Observe and Discuss Observe and Discuss You may have seen the various plants Observe all garden plants like Cycas, which do no

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