Biology Class XI Past Paper PDF - ISC 2026

BIOLOGY (863) CLASS XI There will be two papers in the subject: Paper I: Theory: 3 hours...70 marks Paper II: Practical: 3 hours... 15 marks Project Work …...

BIOLOGY (863) CLASS XI There will be two papers in the subject: Paper I: Theory: 3 hours...70 marks Paper II: Practical: 3 hours... 15 marks Project Work … 10 marks Practical File … 5 marks PAPER 1- THEORY: 70 Marks S.NO. UNIT TOTAL WEIGHTAGE 1. Diversity of Living Organisms 09 Marks 2. Structural Organisation in Animals and Plants 11 Marks 3. Cell: Structure and Function 15 Marks 4. Plant Physiology 17 Marks 5. Human Physiology 18 Marks TOTAL 70 Marks 1  PAPER I –THEORY – 70 Marks Economic importance with reference to role of bacteria in sewage treatment, Note: All structures (internal and external) are antibiotics, energy production and house required to be taught along with diagrams. hold products (curd and cheese only). 1. Diversity of Living Organisms (c) Kingdom Protista – only two general characteristics and two examples (i) The Living World of subgroups: (i) Chrysophytes Need for classification; three domains of (ii) Dinoflagellates, (iii) Euglenoids, life; taxonomy and systematics; concept of (iv) Slime moulds, (v) Protozoans (to be species and taxonomical hierarchy; studied under rhizopods, flagellates, binomial nomenclature. ciliates and sporozoans with two Need for classification should be discussed. characteristics including modes of Three domains of life – distinguishing locomotion and two examples of each). features of (archaea, bacteria, eukarya). (d) Kingdom Fungi: general characteristics Definition and explanation of the terms and mode of reproduction of each taxonomy (numerical taxonomy, (including types of spores and sexual cytotaxonomy and chemotaxonomy) and reproduction – definition of isogamy, systematics. Concept of species. Major anisogamy, oogamy, plasmogamy, taxonomical hierarchies (phylum, class, karyogamy and dikaryophase). order, family, genus, species): definition and Zygomycetes, Ascomycetes, examples with reference to classification of Basidiomycetes, Deuteromycetes - man, house fly, mango and wheat. Rules of characteristics with examples. Role of binomial nomenclature and advantages of fungi in the field of medicine, bakery and using scientific names. environmental decomposition. Definition Three systems of classification – artificial, of lichens and mycorrhiza (ecto and natural and phylogenetic. endo). (ii) Biological Classification Life cycles not required. Five kingdom classification; s alient (e) Virus (characteristic features – link features and classification of Monera, between living and non-living, structure Protista, Fungi, P l a n t a e and Animalia. of TMV and bacteriophage and Lichens, Viruses and Viroids. contribution of the following scientists: D.J. Ivanowsky, M.W. Beijerinck, (a) Five-kingdom system of classification W.M. Stanley) and Viroid (definition and characteristics of different kingdoms only). with examples. (iii) Plant Kingdom (b) Kingdom Monera: Bacteria - classification of bacteria according to (a) Algae - characteristics (morphology, shape, nutrition and mode of respiration; common name, major pigments, stored differences between gram +ve and food, composition of cell wall, flagellar gram –ve bacteria; types of reproduction number and position of insertion, habitat, – definition of fission, conjugation, mode of sexual reproduction) and transduction and transformation (details examples of Chlorophyceae, not required). Phaeophyceae, Rhodophyceae; Economic importance of algae – any five. A brief idea of the role of different types of archaebacteria (methanogens, (b) Bryophyta – general characteristics, halophiles and thermoacidophiles in distinctive features of liverworts and their extreme environments). mosses; graphic outline of life cycle of Mycoplasma – three distinctive features. Funaria with reference to alternation of generations. Economic importance of bryophytes. 2  (c) Pteridophyta: characteristics; thorn, Phylloclade, cladode) and sub- classification into classes: psilopsida aerial (runner, sucker, stolon, offset). (Psilotum), lycopsida (Selaginella, Leaves - parts of a simple leaf, venation, Lycopodium), sphenopsida (Equisetum) types of leaves (simple and compound – and pteropsida (Dryopteris, Pteris and pinnate and palmate), phyllotaxy – Adiantum). Graphic outline of life cycle alternate, opposite, whorled (with an of a typical pteridophyte (fern). Definition example of each). Modifications for of homospory and heterospory with mechanical support (tendril), protection relevant examples. Economic importance. (spine), storage (bulb), reproduction (Bryophyllum); insectivorous plants (d) Gymnosperms: general characteristics (pitcher plant, Venus-fly-trap). and graphic outline of life cycle of a typical gymnosperm (Pinus). Economic (b) Morphology of flower. Structure of a importance. typical flower, types of inflorescence (racemose and cymose). (iv) Animal Kingdom Structure of a typical flower, Animal Kingdom: animal construction - body bracteates/ebracteate, [symmetry plan (cell aggregate plan, blind-sac plan and (actinomorphic, zygomorphic), tube-within-tube plan), symmetry (spherical, trimerous/tetramerous/pentamerous radial and bilateral symmetry), coelom complete/ incomplete, non-essential development (diploblastic and triploblastic whorls (calyx: gamosepalous, organisation in animals, acoelomate, polysepalous, corolla: gamopetalous, pseudocoelomate, coelomate and polysepalous, perianth, aestivation: haemocoelomate), segmentation. valvate, twisted, imbricate, vexillary), Non-chordata - five distinguishing essential whorls (androecium: cohesion - characters with two examples of Porifera, syngenesious, synandrous, Cnidaria, Ctenophora, Platyhelminthes, monadelphous, diadelphous, Nematoda (Aschelminthes), Annelida, polyadelphous; adhesion – epipetalous, Mollusca, Arthropoda, Echinodermata, epiphyllous; number of lobes – Hemichordata. monothecous, dithecous; Gynoecium: Chordata – sub-classification of Chordata position of ovary – epigynous, with reference to notochord - sub phyla hypogynous, perigynous, cohesion – Urochordata, Cephalochordata. Vertebrata apocarpous, syncarpous, number of (classes – cyclostomata, chondrichthyes, locules – unilocular, bilocular, osteichthyes, amphibia, reptilia, aves and multilocular], types of inflorescence mammalia) – three distinguishing characters (racemose and cymose – definition and with two examples of each). differences; subtypes not required). 2. Structural Organisation in Animals and Plants (ii) Anatomy of Flowering Plants (i) Morphology of Flowering Plants Plant Tissues: types of plant tissues: (a) Morphology and modifications of root, Meristematic tissues: classification of stem, leaf. meristematic tissue. Permanent Tissues: structure and function of simple tissues Types of roots (tap, fibrous, adventitious), (parenchyma, collenchyma and regions, modifications of roots for sclerenchyma) and complex tissues (xylem storage (Tuberous – e.g. Mirabilis and and phloem), tissue system. Internal sweet potato; fusiform – e.g. radish; conical – e.g., carrot; napiform – e.g. structure of root, stem, and leaf. turnip), respiration (pneumatophores) Characteristics of meristematic tissue; and support (stilt and prop). classification of meristems based on origin Stems – features (nodes internodes, and location; structure, function and buds), modifications – underground location of permanent tissues; simple and (tuber, rhizome, corm) aerial (tendril, 3  complex tissues; epidermal, ground and ribose and deoxyribose), disaccharides vascular tissue systems. (maltose, lactose and sucrose), polysaccharides (glycogen, starch, cellulose, Cellular diagrams of T.S. of roots and stem inulin, and chitin). and V.S. of monocot and dicot leaves are required. Proteins: amino acids – (structure: glycine, alanine, serine); amino acids as zwitter-ion; (iii) Structural Organisation in Animals: Frog examples of acidic, basic, neutral, sulphur Morphology, anatomy and functions of containing amino acids; essential and non- different systems (digestive, circulatory, essential amino acids; levels of protein respiratory, nervous and reproductive) of structure (primary, secondary, tertiary and frog a brief account only. quaternary); functions of proteins. 3. Cell: Structure and Function Lipids: classification, structure and functions of fats and oils. (i) Cell - the Unit of Life Enzymes: general properties, nomenclature Cell theory and cell as the basic unit of life: and classification of enzymes according to Structure of prokaryotic and eukaryotic type of reactions, co-factors (prosthetic cells; Plant cell and animal cell; cell groups, coenzymes and metal ions). Factors envelope; cell membrane, cell wall; cell affecting enzyme activity - temperature, pH, organelles – ultrastructure and function; substrate concentration. Competitive endomembrane system, mitochondria, inhibitors. ribosomes, plastids, microbodies; (iii) Cell Cycle and Cell Division cytoskeleton, cilia, flagella, centrioles; nucleus. Cell cycle, mitosis, meiosis and their significance. Historical aspects, cell theory, size and Definition of C-value, different stages of cell shape of cells; general structure of cycle (G o , G 1 , S and G 2 and M). prokaryotic cell. Different stages of mitosis and meiosis General structure of eukaryotic cell, ultra- (prophase – I) with diagrams. Significance of structure and function of cell wall mitosis and meiosis. Differences between (including definition of plasmodesmata), mitosis and meiosis. cell membrane [ (description of fluid mosaic model; functions of the plasma 4. Plant Physiology membrane: active and passive transport, (i) Photosynthesis in higher plants brief explanation of facilitated diffusion (uniport, symport and antiport) with one Photosynthesis as a mean of autotrophic example]. Mitochondria, nucleus (nuclear nutrition; site of photosynthesis, pigments membrane, chromatin, nucleolus, structure involved in photosynthesis (elementary and types of chromosomes on the basis of idea); photochemical and biosynthetic the position of centromere, satellite), types phases of photosynthesis; cyclic of plastids, endomembrane system and non-cyclic photophosphorylation; (endoplasmic reticulum, Golgi complex, chemiosmotic hypothesis; photorespiration; lysosomes and vacuoles), ribosomes, C 3 and C 4 pathways; factors affecting microbodies, cytoskeleton (microfilaments, photosynthesis. microtubules and intermediate filaments), cilia, flagella and centrioles; differences Contributions of Priestley, Sachs, between prokaryotic cell and eukaryotic Engelmann, van Neil; differences between cell, plant cell and animal cell. absorption and action spectra. Brief idea of photosynthetic pigments (ii) Biomolecules (difference between chlorophyll ‘a’&‘b’, Proteins, carbohydrates, lipids, enzymes. carotenoids and xanthophyll), photochemical Carbohydrates: general classification and phase - pigment systems, cyclic and non- functions of: monosaccharides (glucose, cyclic photophosphorylation, chemiosmotic 4  hypothesis; biosynthetic phase - C 3 and C 4 5. Human Physiology cycles – graphic representation in correct (i) Breathing and exchange of gases. sequence (carboxylation, glycolytic reversal and regeneration of pentose); Differences Respiratory organs in animals (recall only); between C 3 and C 4 plants, C 3 and C 4 cycles, Respiratory system in humans; mechanism Photosystems I and II, Photorespiration of breathing - exchange of gases, transport pathway in brief - explanation of how RuBP of gases and regulation of breathing, carboxylase acts as RuBP oxygenase. respiratory volumes; disorders related to Kranz anatomy. Blackman’s Law of limiting respiration. factors, factors affecting photosynthesis. Organs involved in respiration; mechanism (ii) Respiration in Plants of pulmonary gas exchange; breathing Exchange of gases; cellular respiration - process should be explained showing the glycolysis, fermentation (anaerobic), TCA action of diaphragm and intercostal cycle a n d electron transport system muscles, regulation of breathing ; transport (aerobic); energy relations - number of ATP of oxygen in the blood, oxyhaemoglobin molecules generated; amphibolic pathways; dissociation curve; transport of CO 2 ; respiratory quotient. chloride shift, pulmonary air volumes and lung capacities; disorders of respiratory Types of respiration; mechanism of system such as - asthma, emphysema, respiration: glycolysis, Krebs’ cycle, ETS occupational respiratory disorders. (only flowchart). Oxidative phosphorylation – definition; Brief idea of fermentation and (ii) Body fluids and circulation. Amphibolic pathway. Definition of Composition of blood, blood groups, respiratory quotient and RQ values of coagulation of blood; composition of lymph carbohydrates, proteins and fats. and its functions; human circulatory system (iii) Plant Growth and Development - structure of human heart and blood Seed germination; phases of plant vessels; cardiac cycle, cardiac output, growth; plant growth rate; ECG; double circulation; regulation of differentiation, dedifferentiation and cardiac activity; disorders of circulatory redifferentiation; sequence of system. developmental processes in a plant cell; Composition of blood plasma, functions of growth regulators - auxin, gibberellin, plasma proteins, blood corpuscles. cytokinin, ethylene, ABA. Importance of ABO groups in blood Definition of seed dormancy and quiescence; transfusion, Rh factor and its importance in causes and methods of breaking seed transfusion and pregnancy; clotting of blood dormancy; definition of hypogeal, epigeal to be taught briefly; lymphatic system – a and viviparous germination with two brief idea of lymph (composition and examples of each. A brief idea about function), Difference between closed and differentiation, dedifferentiation and open vascular system; external and internal redifferentiation. Phases of growth in structure of heart; working of the heart and meristems, growth rate – definition; blood flow through the heart during different measurement of growth by direct method and phases should be described under the use of auxanometer, factors affecting growth. following headings - auricular systole, Discovery and physiological role of growth auricular diastole, ventricular systole, regulators in plants (such as auxins, ventricular diastole and joint diastole; gibberellins, cytokinins, ethylene and definition of stroke volume and cardiac abscisic acid – four effects of each); output, regulation of heart beat, ECG; application of growth regulators. arterial blood pressure (systolic and diastolic), double circulation. The internal structure of artery, vein and capillary. 5  Importance of ABO groups in blood Functions of human skeleton; different types transfusion, Rh factor and its importance in of joints - their location and function; transfusion and pregnancy; clotting of blood general properties of muscles; structure of to be taught briefly; lymphatic system – a skeletal muscle - sliding filament theory of brief idea of lymph (composition and muscle contraction; chemical events during function), lymphatic capillaries and lymph muscle contraction; definition of summation, nodes; disorders of the circulatory system tetanus, rigor mortis, differences between red such as hypertension, coronary artery and white muscles. disease, angina pectoris and heart failure. Disorders of muscular and skeletal system: (iii) Excretory products and their elimination. (i) Myasthenia gravis, (ii) Tetany, (iii Muscular dystrophy, (iv) Arthritis, Modes of excretion - ammonotelism, (v) Osteoporosis, (vi) gout. ureotelism, uricotelism; human excretory system - structure and function; urine (v) Neural Control and Coordination formation, osmoregulation; regulation of Neuron and nerves; nervous system in kidney function, renin - angiotensin, atrial humans - central nervous system; peripheral natriuretic factor, ADH; role of nervous system and visceral nervous erythropoietin; role of other organs in system; generation and conduction of excretion; disorders of the excretory system nerve impulse. - uraemia, renal failure, renal calculi, nephritis; dialysis and artificial kidney, Structure and functions of various parts of kidney transplant. the brain and spinal cord; conduction of nerve impulses through nerve fibre (non- Define, differentiate and explain the terms myelinated and myelinated) and through ammonotelism, ureotelism and uricotelism; synapse. external and internal structure of the kidney (L.S.); structure of nephron; physiology of (vi) Chemical Co-ordination and Integration urine formation - ultra filtration, selective Endocrine glands and hormones; human reabsorption and active (tubular) secretion. endocrine system - hypothalamus, pituitary, Counter current system, regulation of urine pineal, thymus, thyroid, parathyroid, adrenal, formation, definition of micturition, renin- GI tract, pancreas, gonads; mechanism of angiotensin-aldosterone system, role of atrial hormone action (elementary idea); role of natriuretic factor, ADH and erythropoietin. hormones as messengers and regulators, Role of skin, liver and lungs in excretion. hypo - and hyperactivity and related Homeostasis – definition. Disorders of the disorders; dwarfism, acromegaly, cretinism, excretory system - uraemia, renal failure, goiter, exophthalmic goiter, diabetes renal calculi, nephritis. mellitus and diabetes insipidus, Grave’s disease, Addison's disease. Haemodialysis and artificial kidney. Kidney transplant. Brief idea of location of endocrine glands; role of hypothalamus; hormones secreted by (iv) Locomotion and Movement different lobes of pituitary and their Types of movement - ciliary, flagellar, functions; feedback control of tropic muscular; skeletal muscles - contractile hormones to be discussed giving examples; proteins and muscle contraction; skeletal hormones of pineal, thymus, thyroid, system and its functions; joints; disorders parathyroid, pancreas, adrenal glands, GI of muscular and skeletal system. tract (gastrin, secretin, GIP, CCK-PZ) and gonads; mechanism of hormone action Locomotion: Basic aspects of human (through cAMP and steroid hormones only); skeleton (number and names of the bones of effects of hypo secretion and hyper secretion axial and appendicular skeleton). of various hormones of the above mentioned glands. 6  Note: Diseases related to all the human Leaves: phyllotaxy – alternate, opposite physiological systems to be taught in brief. whorled (with an example of each), shape, venation, simple and compound. PAPER II (ii) Preparation of temporary slides of Mucor / PRACTICAL WORK – 15 Marks Rhizopus. 1. Scientific Techniques The teacher should guide the students on the To study parts of a dissecting microscope and technique of culture, staining and mounting compound microscope. the material and then observing under the microscope. The students should also be able The students should know all parts of dissecting to make labelled diagrams and record and compound microscope and be able to handle observations. the microscope independently. 4. Cytology 2. Physiology Preparation of temporary slides of - (i) Food tests: test for starch, glucose, sucrose, (i) Onion peel (to study the plant cell) proteins and fats. (ii) Stages of mitosis in onion root tips. Food tests: tests should be reported in Correct method of selecting the root tip, fixing, tabular form. Both positive and negative tests staining and mounting should be taught. should be reported. Different stages should be observed first in low (ii) To study the effect of thawing, heat and power and after locating the area, the students alcohol on permeability of beet root cells. should see it under high power. Various stages should be drawn and labelled. To study the effect of heat on permeability of cell membrane of beet root cells: students (iii) T.S of monocot and dicot stem. should record the observations at very low (iv) T.S. of monocot and dicot root. temperature, room temperature and higher After staining and mounting the tissue students temperature to see the degree of leaching should be able to draw the diagram and label all and conclude accordingly. Experiment on the parts as seen under the low power of effect of alcohol on the permeability with microscope. regard to leaching. 5. Spotting: (Three minutes to be given for each (i) Separation of plant pigments from leaves by spot which includes identification, drawing a chromatography. labelled diagram and writing at least two (ii) Effect of different carbon dioxide characteristics). concentrations on the rate of photosynthesis. (a) Identification of stained preparations of the following: (iii) Demonstration of plasmolysis (using Rhoeo leaf / onion bulb). (i) Stages of meiosis. (iv) Demonstration of osmosis in living plant (ii) Identification of mammalian blood cells. cells (potato osmoscope). (iii) Bacteria 3. Morphology (iv) Spirogyra (v) Amoeba (i) Morphology and modification of roots, stems and leaves. (vi) Yeast (b) Identification of the following specimens - Teachers can show examples of roots, stems and leaves modified for mechanical support, (i) Liverworts storage, reproduction or perennation – (ii) Moss students should learn to identify and draw the (iii) Fern specimens. (iv) Pinus 7  (v) Mushroom − Moulds. (vi) One monocot plant – bamboo − Setting up of an aquarium. (vii) One dicot plant – Petunia Suggested Evaluation Criteria for Project Work: (viii) Sponge Format of the Project: (ix) Hydra (x) Tape worm – Content – Introduction (xi) Leech – Presentation (graphs, tables, charts, newspaper (xii) Silk Worm cuttings, diagrams, photographs, statistical (xiii) Rohu fish analysis if relevant) Students should be taught how to identify, – Conclusion/ Summary draw, label and give at least two significantly – Bibliography visible characteristics, as observed, of each spot, in a given time of three minutes. Practical File – 5 Marks (c) Comment on experimental set up studied in Each practical done during the year, needs to be physiology. recorded by the student in the Practical file and the same must be checked, signed and dated by (a) Osmosis the teacher. (b) Transpiration Teachers are required to assess students on the basis (c) Photosynthesis of the Biology Practical file maintained by them (d) Transpiration pull. during the academic year. Students should identify (aim of the SCIENTISTS AND THEIR CONTRIBUTIONS experiment), draw a labelled diagram of the 1. Beijerinck – Contagium vivum fluidum physiological set-up and write observation 2. Carl Woese – Three domains of life and inference of the experiment within the allotted time i.e., 3 minutes. 3. Engelmann – Action spectrum of photosynthesis 4. Ernst Mayr – Biological species concept PROJECT WORK AND PRACTICAL FILE – 5. F.F. Blackman – Law of limiting factor 15 Marks 6. F W Went – Isolated Auxins Project Work – 10 Marks 7. Farmer and Moore – Discovered meiosis Candidate is to creatively execute one project/assignment on any aspect of Biology. 8. G.N. Ramachandran – Analysis of Protein Preference is to be given to investigatory projects. structure Following is only a suggestive list of projects. 9. George Palade – Discovered ribosomes Teachers may assign or students may choose any one 10. Huxley and Niedergerke – Sliding filament project of their choice. theory (i) Project related to experiment on any aspect of 11. Ivanowsky – Discovered Tobacco Mosaic Virus plant life/animal life. 12. Karl Landsteiner – Blood groups (ii) Project related to any aspect of environment. 13. Katherine Esau – Anatomy of plants (iii) Diabetes. 14. Peter Mitchell – Chemiosmotic coupling (iv) Endocrine disorders. hypothesis (v) Yeast fermentation and production of alcohol or 15. Priestley – Plants restore oxygen in the air any other commercial industry dependant on plants and/or animals or their products. 16. Robert Brown – Discovered nucleus In addition, students may be taught how to 17. Singer and Nicolson – Proposed fluid mosaic culture: model of plasma membrane − Earthworms. 18. Sutherland – cyclic AMP as second messenger − Protozoans. 19. T. O. Diener – Discovered viroids 8 20. Thomas Addison – Father of endocrinology 11. GFR – Glomerular Filtration Rate 21. Van Neil – Oxygen released during 12. GIP – Gastric Inhibitory Peptide photosynthesis comes from water 13. IBA – Indole Butyric Acid 22. W. M. Stanley – Crystallised TMV 14. IRV – Inspiratory Reserve Volume 23. Waldeyer – Coined the term chromosome 15. LHC – Light Harvesting Complex 24. Whittaker – Five kingdoms of life 16. NAA – Naphthalene Acetic Acid 25. William Harvey – Discovered circulatory system 17. NADPH – Nicotinamide Adenine Dinucleotide Phosphate (reduced) LIST OF ABBREVIATIONS TO BE STUDIED 18. OAA – Oxaloacetic Acid 1. 2,4-D – 2, 4-Dichlorophenoxy acetic acid 19. PGA – Phosphoglyceric Acid 2. ABA – Abscisic Acid 20. PGRs – Plant Growth Regulators 3. ANF – Atrial Natriuretic Factor 21. PPLO – Pleuro Pneumonia Like Organism 4. CCK –Cholecystokinin 22. PZ – Pancreozymin 5. ECG – Electrocardiogram 23. RQ – Respiratory Quotient 6. ERV – Expiratory Reserve Volume 24. RUBISCO – Ribulose Bisphosphate Carboxylase Oxygenase 7. ETS – Electron Transport System 8. FAD – Flavin Adenine Dinucleotide 25. RuBP – Ribulose Bisphosphate 26. TMV – Tobacco Mosaic Virus 9. FRC – Functional Residual Capacity 10. GA – Gibberellic acid 9