Visit ww.ncerthelp.com For All NCERT solutions, CBSE sample papers, Question papers, Notes for Class 6 to 12 Chapter-2 BIOLOGICAL CLASSIFICATION POINTS TO REMEMBER SYSTEMS OF + Earliest Classification was given by Aristotle CLASSIFICATION Divided plants into herbs, shrubs and trees. Animals into those with RBC’s and those who do; not have it *Twokingdom classification : Given by Carolous Linnaeus — Plant kingdom and Animal kingdom, + Five kingdom classification ; By R. H Whittaker. Monera, Protista, Fungi, Plantae and Animalia are the five kingdoms. Kingdom Monera : + Has bacteria a sole member. * Bacteria can have shapes like : Coccus (spheri cal), Bacillus (rod-shaped), Vibrio (comma, shaped) and sprillum (spiral shaped). * Bacteria found almost everywhere and can be Photosynthetic autotrophs, Chemosynthetic au’ totrophs or Heterotrophs + Halophiles (salt-loving) + Thermoacidophiles (in hot springs) Bacteria + Methanogens (in marsh and in gut of ruminant animals. Produce methane gas.) Eubacteria : + Photosynthetic autotrophs like Cyanobacteria. Some like Anabaenahave specialised cells called heterocysts for nitrogen fixation, + Chemosynthetic autotrophs ; Oxidise various inorganic substances like nitrates/nitrites, ammonia and use released energy for their ATP production (6] Please Visit www.ncerthelp.com For Video lectures of all subjects Class 9 to 12Wisit ww.ncerthelp.com For All NCERT solutions, wt CBSE sample papers, Question papers, Notes for Class 6 to 12 ‘wut nesttelp com jerotrophic bacteria : Decompases, help in making curd, production of amibi tics, N, fixation, cause diseases like chol era, typhoid. Mycoplasma : Completely lack cell wall. Smallest living cells. Can survive without oxygen. Pathogenic in animals and plants. Kingdom Prostita (All single celled eukaryotes) + Forms a link between plants, animals and fungi. Chrysophytes (Has diatoms and golden algae) *Cell walls have silica and cell walls overlap to fit together like a soap box + Their accumulation forms “Diatomaceous Earth’ * Used in polishing, filtration of oils and syrups. (ii) Dinoflagellates : + Marine, photosynthetic, cell wall has cellulose. + Two flagella ~one longitudinal and other transversely in a furrow between wall plates. (iii) Euglenoids : + Have protein rich layer ‘pellicle’ which makes body flexible. * Photosynthetic in presence of sunlight but become heterotrophs if they do not get sunlight (iv) Slime Moulds ; + Saprophytic protists + Form aggregates to form plasmodium grows on decaying twigs and leaves, + Spores have true walls which are extremely resistant and survive for many years (v) Protozoans : Amoeboid Flagellated : More flagella. Cause disease like sleeping sickness ¢.., Trypanosoma: ‘atch prey using pseudopodia, ¢.¢., Amoeba, Ciliated : Have cilia to move food into gullet and help in locomotion. e.g. Paramecium. Sporozoans : Have infective spore like stage in lifecycle. .9., Plasmodium which causes Malaria. KINGDOM FUNGI «Non chlorophyllous hyphae {7] Please Visit www.ncerthelp.com For Video lectures of all subjects Class 9 to 12Wisit www.ncerthelp.com For All NCERT solutions, at CBSE sample papers, Question papers, Notes for Class 6 to 12 ‘owwmrnearitelp com «Network of hyphae called mycelium: * Cell wall of chitin and polysaccharides + Grow in warm and humid places + Saprophytic, parasitic, symbiotic (Lichen) e.g., Puccinia (rust causing), Penicillium, CLASSES OF FUNGI Phycomycetes : + grow on decaying wood + Mycelium septate + Spores produced endogenously + Asexual reproduction by Zoospores or Aplanospores ©.g., Rhizopus, Albugo Gi) Ascomycetes : * Also known as “sac fungi* * Mycelium branched and septate * Spores : Asexual spores are called conidia produced exogenously on the conidiophores. Sexual spores are called ascospares produced endogenously in ascus produced inside fruiting body called Ascocarp. &.g., Aspergillus, Neurospora. + Mycelium septate. * Asexual spores generally are not found. + Vegetative reproduction by fragmentation. + Sexual reproduction by fusion of vegetative or somatic cells to form basidium produced in basidiocasp. Agaricus, Ustilago. led as “Fungi Imperfecti’ as sexual form (per fect stage) is not known for them. (iv) Deuteromycetes * Once sexual form is discovered the member is moved to Ascomycetes or Basidiomycetes. [8] ease Visit www.ncerthelp.com For Video lectures of all subjects Class 9 to 12Visit ww.ncerthelp.com For All NCERT solutions, with, CBSE sample papers, Question papers, Notes for Class 6 to 12 © wmmrncerttete com * Mycelium is septate and branched * Are saprophytic, parasitic or decomposers. e.g. Aternaria, Colletotrichum, Viruses They did not find a place in classification, Take over the machin ery of host cell on entering it but as such they have inert crystalline re. So, difficult to call them living or nondliving. * Pasteur gave the term ‘Virus’ Le., poisonous fluid + D. J. Ivanowsky found out that certain microbes caused Tobacco Mosaic Disease in tobacco plant +M.W, Beijerinek called fluid as ‘Contagium vivum fluidum' as extracts of infected plants of tobacco could cause infection in healthy plants, + W. M, Stanely showed viruses could be erystallised to form crystals of protein which are inert outside their specific host. Structure of Virus: + Its a nucleoprotein made up of protein called (Capsid. Capsid is made up of capsomeres arranged in halical or polygeometric forms, Have either DNA or RNA as genetic material which may be single or double stranded. + Usuallly plant viruses have single stranded RNA; bacteriophages have double stranded DNA and animal viruses have single or double stranded RNA or double siranded DNA. Diseases caused : Mumps, Small pox, AIDS etc, Viroids : + Infectious agent, free RNA (lack protein coat) + RNA has low molecular weight. * Causes potato spindle tuber disease. * Discovered by T. 0. Diener, + Lichens : * Symbiotic association between algal component (Phycobiont) and fungal component (mycobiont). Algae provide food, Fungi provide shelter and absorb nutrients for alga * Goad pollution indicators as they do not grow in polluted areas, (9] Please Visit www.ncerthelp.com For Video lectures of all subjects Class 9 to 12Visit waw.ncerthelp.com For All NCERT solutions, CBSE sample papers, Question papers, Notes for Class 6 to 12 (QUESTION: Very Short Answer Questions (1 mark each) 1. Nostoc and Anabaena have specialised cells called hetercysts. What is the function of these cells” Which group comprises of single celled eukaryotes only ? ‘Which organisms are the chief producers in oceans ? ‘Name the fungus which causes disease in wheat (i) rust (ii) Smut veer Which Ascomycetes has been used extensively in work chemical and genetic Short Answer Questions-II (2 marks each) 6. How are bact ‘classified on basis of their shapes? 7. ‘What is the mole of reproduction in bacteria ? 8. ‘Why are red tides caused and why are they harmful ? 9, Viruses and viroids differ in structure and the diseases they cause, How ? 10, Which class of kingdom fungi has both unicellular as well as multicellular members ? When is a fungus called coprophilous ? Short Answer Questions-I(3 marks exch) L1. Who gave five kingdom classification? What was the criteria used by him ? 12, What are the steps in the sexual cycle in kingdom fungi ? 13, Some symbiotic organisms are very good pollution indicators and composed, of a chlorophyllous and a non-chlorophy lous member, Deseribe them, Long Answer Questis 14, Some primitive relatives of animals live as predators or parasites and are divided into four major groups, Elaborate, 15, Differentiate between various classes of kingdom Fungion the basis of their i) Mycelium, (ii) Types of spores and (iii} Type of fruiting body, Also give two examples for each class ps (§ marks each) Very Short Answers (I mark) 1. Help in nitrogen fixation, [10] Please Visit wwv.ncerthelp.com For Video lectures of all subjects Class 9 to 12Visit ww.ncerthelp.com For All NCERT solutions, nit), CBSE sample papers, Question papers, Notes for Class 6 to 12 © wenrnaertelp com 2. Kingdom Protista 3. Diatoms. 4. (i) Puccinta, (ii) Ustilago 8. Neurospora Short Answers-Il (2, marks each) 6. Bacillus (rod-shaped), Coceus (spherical), Vibrium (comma shaped) and Spirillum (spiral shaped) 7. Mainly by fission; Production of spores in unfavourable conditions, Sexual reproduction by DNA transfer, 8. Rapid multiplication of dinoflagellates like Gonyawlax. Harmful as they e- Jease toxins which kill marine animals, 9 Rete Points to Remember’ 10, Ascomycetes = Yeast (Unicellular), Penicilfiun (Multicellulary, Coprophit- ous means fungi whieh graw on dung, Short Answers-I (3 marks each) 11, R. H, Whittakar, Criteria for classification ; Cell structure, thallus Organisation, mode of nutrition, reproduction and phylogenetic relationships 12, The steps are (i) Plasmogamy : fusion of protoplasm of two motile or nom: motile gametes. Kayogamy : fasion of (wo nucle, (iii) 2) {iv} Dikaryophase in ascomycetes and basidiomyeetes where before karyo gamy two nuclei per cell (ikaryon) 13, Lichens, Refer “Points to Remember” gotic Meiosis to form haploid spores, Long Answers (S marks exch) 14, Protozoans, Refer page no. 21-22, NCERT Text Book of Biology for Class X1 Biology. 15, Refer NCERT Text Book of Biology for Class XI, page no, 23-24. [11] Please Visit www.ncerthelp.com For Video lectures of all subjects Class 9 to 12