CBSE Class 12th (Sr. Secondary) Syllabus 2013

CBSE Class 12th (Sr. Secondary) Syllabus 2013
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AIPMT Syllabus 2013 : Chemistry

Unit : 1 Some basic concepts in Chemistry

Importance of Chemistry, physical quantities and their measurement in Chemistry, SI Units, uncertainty in measurements and use of significant figures, Unit and dimensional analysis, Matter and its nature, laws of chemical combinations, atomic, and molecular, masses mole concept, molar masses, percentage composition and molecular formula, chemical stoichiometry.

Unit : 2 States of matter

Three states of matter, gaseous state, gas laws (Boyle’s Law and Charles Law), Avogadro’s Law, Grahams’Law of diffusion, Dalton’s law of partial pressure, ideal gas equation, Kinetic theory of gases, real gases and deviation from ideal behaviour, van der Waals’ equation, liquefaction of gases and critical points, Intermolecular forces; liquids and solids.

Unit : 3 Atomic structure

Earlier atomic models (Thomson’s and Rutherford) , emission spectrum of hydrogen atom, Bohr’s model, of hydrogen atom, Limitations of Bohr’s model, dual nature of matter and radiation, Heisenberg uncertainty principle, quantum mechanical model of atom (quantum designation of atomic orbitals and electron energy in terms of principal, angular momentum and magnetic quantum numbers), electronic spin and spin quantum numbers, Pauli’s exclusion principle, general idea of screening (constants) of outer electrons by inner electrons in an atom, Aufbau principle, Hund’s rule, atomic orbitals and their pictorial representation, electronic configurations of elements.

Unit : 4 Classification of elements and periodicity in properties

Need and genesis of classification of elements (from Doebereiner to Mendeleev), Modern periodic law and present form of periodic table, Nomenclature of elements with atomic number > 100, electronic configurations of elements and periodic table, electronic configuration and types of elements and s, p, d and f blocks, periodic trends in properties of elements (atomic size, ionization enthalpy, electron gain enthalpy, valence/ oxidation states and chemical reactivity).

Unit : 5 Chemical energetics

Some basic concepts in thermodynamics, first law of thermodynamics, heat capacity, measurement of DU and DH, calorimetry, standard enthalpy changes, thermochemical equations, enthalpy changes during phase transformations, Hess’s Law, standard enthalpies of formation, bond enthalpies and calculations based on them.

Unit : 6 Chemical bonding

Kossel -Lewis approach to chemical bond formation, ionic bonds, covalent bonds, polarity of bonds and concept of electronegativity, valence shell electron pair repulsion (VSEPR) theory , shapes of simple molecules, valence bond theory, hybridization involving s, p and d orbitals and shapes of molecules s and p bonds; Molecular orbital theory involving homounclear diatomic molecules; Hydrogen-bonding.

Unit : 7 Equilibrium

Equilibrium in physical and chemical processes

Equilibrium in physical and chemical processes, dynamic equilibrium, law of chemical equilibrium and equilibrium constant, homogeneous equilibrium, heterogenous equilibrium, application of equilibrium constants, Relationship between reaction quotient Q, equilibrium constant, K and Gibbs’ energy G; factors affecting equilibrium-Le Chateliar’s principle.

Ionic equilibrium

Acids, Bases and Salts and their ionization, weak and strong electrolytes degree of ionization and ionization constants, concept of pH, ionic product of water, buffer solution, common ion effect, solubility of sparingly soluble salts and solubility products.

Unit : 8 Redox reactions

Electronic concepts of reduction - oxidation, redox reactions, oxidation number, balancing of redox reactions.

Unit : 9 Solid state Chemistry

Classification of solids based on different binding forces: molecular, ionic, covalent and metallic solids, amorphous and crystalline solids; unit cells in two dimensional and three dimensional lattices, calculation of density of a unit cell, packing in solids, voids, number of atoms per unit cell in a cubic unit cell, point defects, electrical and magnetic properties.

Unit : 10 Chemical thermodynamics

Spontaneous processes, energy and spontaneity , entropy and second law of thermodynamics, concept of absolute entropy, Gibbs energy and spontaneity, Gibbs energy change and equilibrium constant.

Unit : 11 Solutions

Types of solutions, different units for expressing concentration of solution, mole fraction, percentage (by volume and mass both), definitions of dilute solutions, vapour pressure of solutions and Raoult’s Law, Colligative properties, lowering of vapour pressure, depression of freezing point, elevation of boiling points and osmotic pressure, determination of molecular masses using colligative properties, abnormal values of molecular masses, van’t Hoff factor. simple numerical problems.

Unit : 12 Chemical kinetics

Rate of chemical reactions, factors, affecting rates of reactions –concentration, temperature and catalyst, order and molecularity of reactions, rate law and rate constant, differential and integral forms of first order reaction, half-life (only zero and first order) characteristics of first order reaction, effect of temperature on reactions, Arrhenius theory - activation energy, collision theory of reaction rate (no derivation).

Unit : 13 Electrochemistry

Conductance in electrolytic solutions, specific and molar conductivity, variation of conductivity with concentration, Kohlrausch’s law, electrolysis and laws of electrolysis (elementary idea), electrolytic and galvanic cells, emf. of a cell, standard electrode potential, Nernst equation, concentration cell, fuel cells, cell potential and Gibbs energy, dry cell and lead accumulator.

Unit : 14 Surface chemistry

Adsorption - physisorption and chemisorption, factors affecting adsorption of gases on solids, catalysis, homogeneous and heterogeneous activity and selectivity, enzyme catalysis, colloidal state, distinction between true solutions, colloids and suspensions; lyophillic, lyophobic, multimolecular and macromolecular colloids, properties of colloids, Tyndal effect, Brownian movement, electrophoresis, coagulation, emulsions - type of emulsions.

Unit :15 Hydrogen

Position of hydrogen in periodic table, isotopes of hydrogen, heavy water, hydrogen peroxide-preparation, reactions and structures; hydrides and their classification.

Unit :16 s-Block Elements (Alkali and Alkaline Earth metals): Group 1 and Group 2 elements

Electronic configurations and general trends in physical and chemical properties, anomalous properties of the first element of each group, diagonal relationship.

Preparation and properties of some important compounds, sodium carbonate, sodium hydroxide, sodium hydrogen carbonate and industrial uses of lime and limestone, biological significance of Na, K, Mg and Ca.

Unit : 17 General principles and processes of isolation of elements

Principles and methods of extraction - concentration, reduction, (chemical and electrolytic methods), and refining.

Occurrence and principles of extraction of Al, Cu, Zn and Fe.

Unit : 18 p-Block Elements

Introduction to p-block elements

Electronic configurations and general trends in properties, viz. atomic sizes, ionization enthalpies, electronegativity values, electron gain enthalpies and oxidation states across the periods and down the groups in the p-block.

Unique behaviour of the top element in each group of the block - the covalency limit and the pp - pp overlap in some molecules (e.g. N2, O2) and its consequences; general trend in catenation tendency down each group.

Group-wise study of the p-block Elements

Group 13 - In addition to the general characteristics as outlined above, properties and uses of aluminium, nature of hydrides/ halides and oxides; Properties, structures and uses of diborane boron halides, aluminium chloride, borax, boric acid and alums.

Group 14 - In addition to the general characteristics; carbon – catenation, allotropic forms (diamond and graphite), properties and structures of oxides; silicon - silicon tetrachloride, and structures and uses of silicates, silicones and zeolites.

Group 15 - In addition to the general characteristics, the general trends in the nature and structures of hydrides, halides and oxides of these elements. Preparation and properties of ammonia, nitric acid, phosphine and halides of phosphorus, structures of the oxoacids of phosphorus.

Group 16 - In addition to the general characteristics, preparations, properties and uses of dioxygen, simple oxides, ozone; sulphur - allotropic forms, compounds of sulphur, preparation, properties and uses of sulphur dioxide and sulphuric acid, industrial preparations of sulphuric acid, structures of oxoacids of sulphur.

Group 17 - In addition to the general characteristics, occurrence, trends in physical and chemical properties, oxides and oxoacids of halogens (structures only), preparation, properties and uses of chlorine and hydrochloric acid, trends in the acidic nature of hydrogen halides. Interhalogen compounds (structures only).

Group 18 - General introduction, electronic configurations, occurrence, trends in physical and chemical properties and uses, - fluorides and oxides of xenon (structures only).

Unit :19 The d-and f-Block elements

General introduction, electronic configuration, occurrence and characteristics of transition metals, general trends in properties of the first row transition metals –physical properties, ionization enthalpy, oxidation states, ionic radii, colour, catalytic property, magnetic property, interstitial compounds, alloy formation; preparations and properties of K2Cr2O7 and KMnO4.

Lanthanoids - Electronic configuration and oxidation states, chemical reactivity and lanthanoid contraction.

Actinoids - Electronic configuration and oxidation states.

Unit : 20 Coordination compounds

Introduction to ligands, coordination number, colour, magnetic properties, and shapes; IUPAC - nomenclature of mononuclear coordination compounds, isomerism , bonding-valence bond approach to the bonding and basic ideas of Crystal Field Theory, colour and magnetic properties. Elementary ideas of metal - carbon bonds and organometallic compounds, importance of co-ordination compounds (in qualitative analysis, extraction of metals and biological systems).

Unit : 21 Some basic principles of Organic Chemistry

- Tetravalence of carbon, hybridization ( s and p ), shapes of simple molecules, functional groups:-C=C-, -CC-and those containing halogens, oxygen, nitrogen and sulphur; homologous series, isomerism.

- General introduction to naming organic compounds-trivial names and IUPAC nomenclature.

- Electronic displacement in a covalent bond; inductive effect, electromeric effect, resonance and hyperconjugation. Fission of covalent bond: free radicals, electrophiles and nucleophiles, carbocations and carbonanions.

- Common types of organic reactions: substitution, addition, elimination and rearrangement reactions.

Unit : 22 Hydrocarbons

Alkanes and cycloalkanes : classification of hydrocarbons, alkanes and cycloalkanes, nomenclature and conformations of alkanes and cycloalkanes.

Alkenes and alkynes : Nomenclature and isomerism, general methods of preparation, properties (physical and chemical), mechanism of electrophilic addition, Markownikoff’s rule, peroxide effect, acidic character of alkynes, polymerisation reactions.

Aromatic hydrocarbons : Benzene and its homologues, nomenclature, sources of aromatic hydrocarbons (coal and petroleum), structure of benzene, chemical reaction of benzene-mechanism of electrophilic substitution. Directive influence of substituents and their effect on reactivity.

Petroleum and petrochemicals : Composition of crude oil fractionation and uses, quality of gasoline, LPG, CNG, cracking and reforming, petrochemicals.

Unit : 23 Purification and characterization of carbon compounds

- Purification of carbon compounds : filtration, crystallisation, sublimation, distillation chromatography,

- Qualitative analysis : detection of nitrogen, sulphur, phosphorus and halogens.

- Quantitative analysis : estimation of different elements (H, N, halogens, S and P)

- Determination of molecular masses : Silver salt method, chloroplatinate salt method, calculations of empirical and molecular formulas.

Unit : 24 Organic compounds with functional groups containing halogens (X)

- Nature of C-X bond in haloalkanes and haloarenes, nomenclature, physical and chemical properties, mechanism of substitution reactions, reactivity of C-X bond in haloalkanes and haloarenes.

- Some commercially important compounds : dichloro, trichloro and tetrachloromethanes; p-dichlorobenzene, freons, BHC, DDT, their uses and important reactions.

Unit : 25 Organic compounds with functional groups containing oxygen

Alcohols and phenols : Nomenclature, methods of preparation, physical and chemical properties; chemical reactivity of phenols in electrophilic substitutions, acidic nature of phenol, ethers: electronic structure, structure of functional group, nomenclature, important methods of preparation, physical and chemical properties, some commercially important compounds.

Aldehydes and ketones : Electronic structure of carbonyl group, nomenclature, important methods of preparation, physical properties and chemical reactions, relative reactivity of aldehydic and ketonic groups, acidity of a-hydrogen, aldol condensation. Connizzarro reaction, nucleophilic addition reaction to >C=O groups.

Carboxylic acids : Electronic structure of-COOH, Nomenclature, important methods of preparation, physical properties and effect of substituents on a-carbon on acid strength, chemical reactions.

Derivatives of carboxylic acids : Electronic structure of acid chloride, acid anhydride, ester and amide groups, nomenclature, important methods of preparation, comparative reactivity of acid derivatives. Some commercially important compounds.

Unit : 26 Organic Compounds with functional group containing nitrogen

- Structure, nomenclature of nitro, amino, cyano and diazo compounds.

- Nitro compounds – important methods of preparation, physical properties and chemical reactions.

- Amines : primary, secondary and tertiary amines, a general awareness, important methods of preparation, physical properties, basic character of amines, chemical reactions.

- Cyanides and isocyanides : preparation, physical properties and chemical reactions.

- Diazonium salts : Preparation, chemical reaction and uses of benzene diazonium chloride. Some commercially important nitrogen containg carbon compounds, (aniline, TNT)

Unit : 27 Polymers

Classification of polymers, general methods of polymerization-addition and condensation: addition-free radical, cationic, anionic polymerization, copolymerisation, natural rubber, vulcanization of rubber, synthetic rubbers, condensation polymers, idea of macromolecules, biodegradable polymers.

Some commercially important polymers (PVC, teflon, polystyrene, nylon-6 and 66, terylene and bakelite).

Unit : 28 Environmental Chemistry

Environmental pollution – air, water and soil pollutions, chemical reactions in atmosphere, smogs, major atmospheric pollutants, acid-rain, ozone and its reactions, effects of depletion of ozone layer, green house effect and global warming – pollution due to industrial wastes, green chemistry as an alternative tool for reducing pollution, strategy for controlling environmental pollution.

Unit : 29 Biomolecules

Carbohydrates : Classification, aldose and ketose, monosaccharides (glucose and fructose), oligosaccharides (sucrose, lactose, maltose), polysaccharides (starch, cellulose, glycogen); important simple chemical reactions of glucose, elementary idea of structure of pentose and hexose.

Proteins : Elementary idea of a-amino acids, peptide bond, polypeptides, proteins; primary, secondary and tertiary structure of proteins and quaternary structure (gualitative idea only), denaturation of proteins, enzymes.

Vitamins : Classification and functions

Nucleic acids : Chemical composition of DNA and RNA

Lipids : Classification and structure

Hormones : Classification and functions in biosystem.

Unit : 30 Chemistry in everyday life

- Chemicals in medicines – analgesics, tranquilizers, antiseptics, disinfectants, antimicrobials, antifertility drugs, antacids, antihistamins.

- Chemicals in food – preservativess, artificial sweetening agents.

- Cleansing agents – soaps and detergents, cleansing action.

- Rocket propellants : characteristics and chemicals used.
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AIPMT Syllabus 2013 : Physics

Unit : 1 Introduction and Measurement

What is Physics? Scope and excitement; Physics in relation to science, society and technology; Need for measurement of physical quantities, units for measurement, systems of units-SI : fundamental and derived units. Dimensions of physical quantities. Dimensional analysis and its applications. Orders of magnitude, Accuracy and errors in measurement – random and instrumental errors, Significant figures and rounding off the numbers.

Graphs, Trigonometric functions, Concepts of differentiation and integration.

Unit : 2 Description of Motion in One Dimension

Objects in motion in one dimension, Motion in straight line, Uniform and non-uniform motion, its graphical representation and formulae, speed and velocity, relative velocity, average speed and instantaneous velocity. Uniformly accelerated motion, velocity-time graph, position-time graph and their formulae. Relations for uniformly accelerated motion with examples. Acceleration in one-dimensional motion.

Unit : 3 Description of Motion in Two and Three Dimensions

Vectors and scalars quantities, vectors in two and three dimensions, vector addition and multiplication by a real number, null-vector and its properties. Resolution of a vector in a plane, rectangular components. Scalar and vector products. Motion in two dimensions, cases of uniform velocity and uniform acceleration-projectile motion, general relation among position-velocity-acceleration for motion in a plane and uniform circular motion. Motion of objects in three dimensional space (elementary ideas).

Unit : 4 Laws of Motion

Force and inertia, first law of motion. Momentum, second law of motion, impulse, examples of different kinds of forces in nature. Third law of motion, conservation of momentum, rocket propulsion. Equilibrium of concurrent forces. Static and kinetic frictions, laws of friction, rolling friction, lubrication, Inertial and non-inertial frames (elementary ideas).

Unit : 5 Work, Energy and Power

Work done by a constant force and by a variable force, unit of work, energy and power. Work Energy Theorem. Elastic and in-elastic collisions in one and two dimensions. Notions of potential energy, conservation of mechanical energy : gravitational potential energy, and its conversion to kinetic energy, potential energy of a spring. Conservative forces. Different forms of energy, mass-energy equivalence, conservation of energy.

Unit : 6 Rotational Motion

Centre of mass of a two-particle system, momentum conservation and centre of mass motion. Centre of mass of rigid body, general motion of a rigid body, nature of rotational motion, rotational motion of a single particle in two dimensions only, torque, angular momentum and its geometrical and physical meaning, conservation of angular momentum, examples of circular motion (car on a level circular road, car on banked road, pendulum swinging in a vertical plane). Moment of inertia, its physical significance, moment inertia of uniform bodies with simple geometrical shapes, parallel axis and perpendicular axis theorem (statements only), Comparison between translatory (linear) and rotational motion.

Unit : 7 Gravitation

Acceleration due to gravity, one and two dimensional motion under gravity. Universal law of gravitation, inertial and gravitational mass, variations in the acceleration due to gravity of the earth, statement of Kepler’s laws of planetary motion, orbital velocity, geostationary satellites, gravitational potential, gravitational potential energy near the surface of earth, escape velocity, weightlessness.

Unit : 8 Heat and Thermodynamics

Thermal equilibrium and temperature ( zeroth law of thermodynamics). Heat, work and internal energy. Specific heat, specific heat at constant volume and constant pressure of ideal gas and relation between them. First law of thermodynamics. Thermodynamic state, equation of state and isothermals, pressure-temperature phase diagram. Thermodynamic processes (reversible, irreversible, isothermal, adiabatic). Carnot cycle, second law of thermodynamics, efficiency of heat engines. Entropy. Transfer of heat : conduction, convection and radiation. Newton ’s law of cooling.

Thermal conductivity. Black body radiation, Wien’s law, Solar constant and surface temperature of the sun, Stefan’s law,

Unit : 9 Oscillations

Periodic and oscillatory motions. Simple harmonic motion (S.H.M.) and its equation of motion. Oscillations due to a spring, kinetic energy and potential energy in S.H.M., Simple pendulum, physical concepts of forced oscillations, resonance and damped oscillations; Simple examples.

Unit : 10 Waves

Longitudinal and transverse waves and wave motion, speed of progressive wave. Principle of superposition of waves; reflection of waves, harmonic waves (qualitative treatment only), standing waves. Normal modes and its graphical representation. Beats, Doppler effect.

Unit : 11 Electrostatics

Frictional electricity, charges and their conservation, unit of charge, Coulomb’s law, dielectric constant, electric field, electric field due to a point charge, electric potential – its physical meaning, potential due to a di-pole, di-pole field and behaviour of dipole in a uniform (2-dimensional) electric field. Flux, Statement of Gauss’s theorem and its applications to find electric field due to uniformly charged simple systems. Conductors and insulators, presence of free charges and bound charges inside a conductor, Capacitance (parallel plate), Dielectric material and its effect on capacitance (concept only), capacitances in series and parallel, energy of a capacitor. Van de Graff generator.

Unit : 12 Current Electricity

Introduction (flow of current), sources of e.m.f., cells : simple, secondary, chargeable, combinations of cells in series and parallel. Electric current, resistance of different materials, temperature dependence, thermistor, specific resistivity, colour code for carbon resistors. Ohm’s law and its limitation. Superconductors (elementary ideas). Kirchoff’s laws, resistances in series and parallel, Wheatstone’s bridge, measurement of resistance. Potentiometer – measurement of e.m.f. and internal resistance of a cell.

Unit : 13 Thermal and Chemical Effects of Currents

Electric power, heating effects of current and Joule’s law. Thermoelectricity: Seebeck effect, measurement of temperature using thermocouple. Chemical effects and Faraday’s laws of electrolysis.

Unit : 14 Magnetic Effect of Currents

Oersted’s observation, Biot-Savart’s law (magnetic field due to an element of current), magnetic field due to a straight wire, circular loop and solenoid. Force on a moving charge in a uniform magnetic field (Lorentz force), cyclotron (simple idea), forces and torques on currents in a magnetic field, forces between two currents, definition of ampere, moving coil galvanometer, ammeter and voltmeter. Conversion of galvanometer into voltmeter/ammeter.

Unit : 15 Magnetism

Bar magnet (comparison with a solenoid), magnetic lines of force, torque on a bar magnet in a magnetic field, earth’s magnetic field as a bar magnet, tangent galvanometer, vibration magnetometer. Para, dia and ferromagnetic substances with examples (simple idea). Electromagnets and permanent magnets.

Unit : 16 Electromagnetic Induction and Alternating Currents

Faraday’s Law of electromagnetic induction, Lenz’s Law, induced emf, self and mutual inductance. Alternating current, and voltage, impedance and reactance; A.C. circuits containing inductance, capacitance and resistance; phase relationships, and power in a.c. circuits, L.C oscillations. Electrical machines and devices (transformer, induction coil, generator, simple motors, choke and starter), eddy current.

Unit : 17 Electromagnetic Waves (Qualitative Treatment)

Electromagnetic oscillations, brief history of electromagnetic waves (Maxwell, Hertz, Bose, Marconi). Electromagnetic spectrum (radio, micro-waves, infra-red, optical, ultraviolet, X-rays, gamma rays) including elementary facts about their uses, propagation of electromagnetic waves in atmosphere.

Unit : 18 Ray Optics and Optical Instruments

Ray optics as a limiting case of wave optics. Phenomena of reflection, refraction, and total internal reflection. Optical fibre. Curved mirrors, lenses; mirror and lens formulae. Dispersion by a prism. Spectrometer. Absorption and emission spectra. Scattering and formation of rainbow. Telescope (astronomical), microscope, their magnifications and resolving powers.

Unit : 19 Electrons and Photons

Discovery of electron, e/m for an electron, electrical conduction in gases, photoelectric effect, particle nature of light, Einstein’s photoelectric equation, photocells. Matter waves – wave nature of particles, de-Broglie relation, Davison and Germer experiment.

Unit : 20 Atoms, Molecules and Nuclei

Rutherford model of the atom, Bohr model, energy quantization. Hydrogen spectrum. Composition of nucleus, atomic masses, binding energy per nucleon of a nucleus, its variation with mass number, isotopes, size of nucleus. Radioactivity : properties of a, b and g rays. Mass energy relation, nuclear fission and fusion.

Unit : 21 Solids and Semiconductor Devices

Crystal structure-Unit cell; single, poly and liquid crystals (concepts only). Energy bands in solids, difference between conductors, insulators and semi-conductors using band theory. Intrinsic and extrinsic semiconductors,
p-n junction, semiconductor diodes, junction transistor, diode as rectifier, solar cell, photo diode, LED, Zener diode as a voltage regulator, transistor as an amplifier and oscillator. Combination of gates. Elementary ideas about IC.
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AIPMT Syllabus 2013 : Biology

Unit : 1 Diversity in Living World

Biology – its meaning and relevance to mankind

What is living; Taxonomic categories and aids (Botanical gardens, herbaria, museums, zoological parks); Systematics and Binomial system of nomenclature.

Introductory classification of living organisms (Two-kingdom system, Five-kingdom system); Major groups of each kingdom alongwith their salient features (Monera, including Archaebacteria and Cyanobacteria, Protista, Fungi, Plantae, Animalia); Viruses; Lichens

Plant kingdom – Salient features of major groups (Algae to Angiosperms);

Animal kingdom – Salient features of Nonchordates up to phylum, and Chordates up to class level.

Unit : 2 Cell : The Unit of Life ; Structure and Function

Cell wall; Cell membrane; Endomembrane system (ER, Golgi apparatus/Dictyosome, Lysosomes, Vacuoles); Mitochondria; Plastids; Ribosomes; Cytoskeleton; Cilia and Flagella; Centrosome and Centriole; Nucleus; Microbodies.

Structural differences between prokaryotic and eukaryotic, and between plant and animal cells. Cell cycle (various phases); Mitosis; Meiosis.

Biomolecules – Structure and function of Carbohydrates, Proteins, Lipids, and Nucleic acids.

Enzymes – Chemical nature, types, properties and mechanism of action.

Unit : 3 Genetics and Evolution

Mendelian inheritance; Chromosome theory of inheritance; Gene interaction; Incomplete dominance; Co-dominance; Complementary genes; Multiple alleles;

Linkage and Crossing over; Inheritance patterns of hemophilia and blood groups in humans.

DNA –its organization and replication; Transcription and Translation; Gene expression and regulation; DNA fingerprinting.

Theories and evidences of evolution, including modern Darwinism.

Unit : 4 Structure and Function – Plants

Morphology of a flowering plant; Tissues and tissue systems in plants;

Anatomy and function of root, stem(including modifications), leaf, inflorescence, flower (including position and arrangement of different whorls, placentation), fruit and seed; Types of fruit; Secondary growth;

Absorption and movement of water (including diffusion, osmosis and water relations of cell) and of nutrients; Translocation of food; Transpiration and gaseous exchange; Mechanism of stomatal movement.

Mineral nutrition – Macro- and micro-nutrients in plants including deficiency disorders; Biological nitrogen fixation mechanism.

Photosynthesis – Light reaction, cyclic and non-cyclic photophosphorylation; Various pathways of carbon dioxide fixation; Photorespiration; Limiting factors .

Respiration – Anaerobic, Fermentation, Aerobic; Glycolysis, TCA cycle; Electron transport system; Energy relations.

Unit : 5 Structure and Function - Animals

Tissues;Elementary knowledge of morphology, anatomy and functions of different systems of earthworm, cockroach and frog.

Human Physiology – Digestive system - organs, digestion and absorption; Respiratory system – organs, breathing and exchange and transport of gases. Body fluids and circulation – Blood, lymph, double circulation, regulation of cardiac activity; Hypertension, Coronary artery diseases.

Excretion system – Urine formation, regulation of kidney function

Locomotion and movement – Skeletal system, joints, muscles, types of movement.

Control and co-ordination – Central and peripheral nervous systems, structure and function of neuron, reflex action and sensory reception; Role of various types of endocrine glands; Mechanism of hormone action.

Unit : 6 Reproduction, Growth and Movement in Plants

Asexual methods of reproduction; Sexual Reproduction - Development of male and female gametophytes; Pollination (Types and agents); Fertilization; Development of embryo, endosperm, seed and fruit (including parthenocarpy and apomixis).

Growth and Movement – Growth phases; Types of growth regulators and their role in seed dormancy, germination and movement; Apical dominance; Senescence; Abscission; Photo- periodism; Vernalisation; Various types of movements.

Unit : 7 Reproduction and Development in Humans

Male and female reproductive systems; Menstrual cycle; Gamete production; Fertilisation; Implantation; Embryo development; Pregnancy and parturition; Birth control and contraception.

Unit : 8 Ecology and Environment

Meaning of ecology, environment, habitat and niche.

Ecological levels of organization (organism to biosphere); Characteristics of Species, Population, Biotic Community and Ecosystem; Succession and Climax.

Ecosystem – Biotic and abiotic components; Ecological pyramids; Food chain and Food web; Energy flow; Major types of ecosystems including agroecosystem.

Ecological adaptations – Structural and physiological features in plants and animals of aquatic and desert habitats.

Biodiversity – Meaning, types and conservation strategies (Biosphere reserves, National parks and Sanctuaries)

Environmental Issues – Air and Water Pollution (sources and major pollutants); Global warming and Climate change; Ozonedepletion; Noise pollution; Radioactive pollution; Methods of pollution control (including an idea of bioremediation); Deforestation; Extinction of species (Hot Spots).

Unit : 9 Biology and Human Welfare

Animal husbandry – Livestock, Poultry, Fisheries; Major animal diseases and their control. Pathogens of major communicable diseases of humans caused by fungi, bacteria, viruses, protozoans and helminths, and their control.

Cancer; AIDS.

Adolescence and drug/alcohol abuse;

Basic concepts of immunology.

Plant Breeding and Tissue Culture in crop improvement.

Biofertilisers (green manure, symbiotic and free-living nitrogen-fixing microbes, mycorrhizae);

Biopesticides (micro-organisms as biocontrol agents for pests and pathogens); Bioherbicides;

Microorganisms as pathogens of plant diseases with special reference to rust and smut of wheat, bacterial leaf blight of rice, late blight of potato, bean mosaic, and root - knot of vegetables.

Bioenergy – Hydrocarbon - rich plants as substitute of fossil fuels.

Unit : 10 Biotechnology and its Applications

Microbes as ideal system for biotechnology;

Microbial technology in food processing, industrial production (alcohol, acids, enzymes, antibiotics), sewage treatment and energy generation.

Steps in recombinant DNA technology – restriction enzymes, DNA insertion by vectors and other methods, regeneration of recombinants.

Applications of R-DNA technology. In human health –Production of Insulin, Vaccines and Growth hormones, Organ transplant, Gene therapy. In Industry – Production of expensive enzymes, strain improvement to scale up bioprocesses. In Agriculture – GM crops by transfer of genes for nitrogen fixation, herbicide-resistance and pest-resistance including Bt crops.
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India - Resources and their Development


1. Resources : Types - natural and human; Need for resource planning. (Chapter 1)
2. Natural Resources : land as a resource, soil types and distribution; changing land-use pattern; land degradation and conservation measures.(Chapter 1)
3. Forest and Wild life resources : types and distribution ,depletion of flora and fauna; conservation and protection of forest and wild life. (Chapter 2)
4. Water resources : sources, distribution, utilisation, multi-purpose projects, water scarcity, need for conservation and management, rainwater harvesting. (One case study to be introduced) (Chapter 3)
5. Agriculture : types of farming, major crops, cropping pattern, technological and institutional reforms; their impact; contribution of Agriculture to national economy - employment and output. (Chapter 4)

Term II
6. Mineral Resources : types of minerals, distribution, use and economic importance of minerals, conservation. (Chapter  5) 
7. Power Resources : types of power resources : conventional and non-conventional, distribution and
utilization, and conservation. (Chapter 6)
8. Manufacturing Industries : Types, spatial distribution, contribution of industries to the national
economy, industrial pollution and degradation of environment, measures to control degradation. (One
case study to be introduced) (Chapter 7)
9. Transport, communication and trade (Chapter 8)
10. Map Work (3 marks) 

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Generating Awareness on Disaster Management

Disasters - a growing problem around the world.It's a fact - disasters are on the rise around the world. According to one estimate, the 1990s saw a tripling of disasters and a nine-fold increase in economic costs when compared with the 1960s. Climate change,earthquake,floods,storm increasing concentrations of people in vulnerable areas, and political and economic instability are all contributing factors. The challenge is - how do we deal with this growing dilemma?


World Vision Bangladesh, Mymensingh ADP for Disaster Management organised essay, quiz, debate and paintings competitions at its auditorium on September 28 to create awareness among children about the disaster management programme. The participants came from different schools sponsored by World Vision. A total of 120 children took part in the day long competitions.

The children took part in the painting competition in three groups. The theme was 'disaster and necessary measures before or after a natural disaster takes place'.

Later a discussion was held with Disaster Management official of World Vision, Md. Abdul Barek in the chair. Samarendra Sangma, manager of Mymensingh ADP, was the chief guest. Assistant Keeper of Zainul Abedin Sangrahashala Dulal Chandra Gain, Professor Pradip Kumar Biswas, journalist Fazlur Rahman Siddiqui, Professor Shamsul Fayez and art teacher of Mymensingh Zila School, Hasan Masud also spoke at the event.

The speakers said that since Bangladesh is a country troubled with natural calamities, our youngsters should be more aware of how to deal with the situation.

At the end of the programme the chief guest distributed prizes among the winners.

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Full Form of CGPA ?

Cumulative Grade Point Average.

What is CGPA ?

It is an overall indicative percentage of marks.

How to calculate percentage from CGPA ?

Multiply the CGPA with 9.5 or use the above calculator to get the indicative percentage.

Why multiply with 9.5 only ?

The Board took the result of the last five years and calculated the average marks of all candidates who had scored between 91 and 100. That average turned out to be close to 95 marks. Since the equivalent Grade Point for the 91-100 band (A1 grade) of marks is 10, it then divided the average result of 95 by 10. The result is 9.5.



he CGPA is the average of Grade Points obtained in all the subjects excluding additional 6th subject as per Scheme of Studies.
An indicative equivalence of Grade Point and Percentage of Marks can be assessed as follows:

  • Subject wise indicative percentage of marks = 9.5 x GP of the Subject.
  • Overall indicative percentage of marks = 9.5 x CGPA

The above formula given by CBSE to convert grades into marks and percentage is only an approximation and not exact.

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CBSE CCE Grading System : Student's Corner



Actually i want to advice you that with this grades boards should give percentage also as we can compare ourselves.
since a child getting 99.5% and 95% will be in the same grade and hence will not able to know who performed better.
Implementation aspect should get the attention it deserves, if the system is to achieve its stated objectives. For teachers to make an objective assessment of the students, the work of the students will have to be closely guided and supervised. This will be possible only if the number of students a teacher is required to handle is kept limited. In the present class room environment, in most of the schools, where this number goes upwards of 40, this will remain a distant dream.
The structure of our classes should have been revamped first before the introduction of the new system. The system will take time to stabilise and the students who are forced to go through it during the transition phase may end up as losers.
The new system by itself has lot of merit in it. The utility will depend on the implementation. For a grading system to work effectively, the assessment method has to be fool proof and criteria well defined. There should not be any room for subjectivity here.
The fear expressed in many comments here about no more competition amongst the students and heart burns for the topper are all unfounded. Competition will still be there as one has to work hard and perform well to even score 90%. Heart burn of one is OK, if it can save the pain of peer pressure and parental pressure from a majority of students. This will ultimately lead to pressure free environment for students and encourage ‘healthy competion’ between them.
The system which is taken in pressure of about 10-20 students every year who commited sucide then why should 5000000 students.
the general students are 2 fold loss 1st seat reservations and then grading.
CAN A 96% is given equal importance as given to 91% one????
the sprit of competion will not be seen any where.
so all my dear friends lets come together and protest against it.
What exactly is the point of this new grading system?
We slog throughout the year and crack our brains over getting good marks in the board,but it does give one a certain amount of satisfaction to see the results at the end of the year.
What,they want to take this satisfaction away too?
At the same time,there is the fact that loads of students get above 90% in their board exams.
What if these students want to shift from their present school?
How will schools decide on which students to select?
Will we have to face another entrance exam AFTER our boards too?
Or will we have to give huge donations of money for admission?
This system is surely encouraging corruption…
This system is mainly put to stop suicide i guess im going to commit it!!!!!
problem is one-teacher take advantage and ask loads and loads of homwork in 1 day.dont get it and their words “now see….i will cut your marks and give you 0 im soo happy”
two-its a waste of resouces
three-teachers take their pets to their sides=give them good grades
four- dont get a copy or book and bang your gone
well these sre the main problems i face there are many more but that doesn’t effect me so i want CBSE back with logic and not rote and no projects no child likes it i have done a serveythat out of 47 kids in a class only 10 are happy rest sad the sad 1s include toppers I UNDERSTAND WHAT YOU ARE TRYING TO DO BUT IT WOULD BE FUN ONLY IF TEACHERS UNDERSTOOD US !!!
I appreciate the implentation of grading system. We can avoid both the mental torture to the students by their own parents and the suicide of of our immatured children to a certain extent.
Even after the aboiltion of grading,the recurring of suicides by the students,it should be answerable and cannot be compensated by money in the name of” Interim reliefs” to the family of the victim.
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CCE Grading System

HOW CBSE’S GRADING SYSTEM WILL WORK
  1. All students have been awarded grades, not marks
  2. The practice of declaring Compartment/Fail has been discontinued
  3. The result of candidates is now declared in two cate¬gories: Eligible for qualifying certificate (QUAL) and Eligible for improvement of performance (EIOP)
  4. All candidates, even if they have failed in all subjects will now have five chances to improve their performance without having to repeat a year.
THE NEW ORDER
With Board exams being made optional from the academic year 2010-11, a new system of evaluation – Continuous and Comprehensive Evaluation (CCE) – based on grades has been approved. It comprises formative and summative assessment of the student to be done over two terms – first and second -during the year-long academic calendar.
Summative Assessment: Based on the term-end examinationFormative Assessment: To evaluate and grade class work, homework, assignment and project work
1) There will be two evaluations each in the first and second terms.
2) Each evaluation will carry 10 marks apiece.
1) There will be one term-end exam for each term.
2) The first term-end exam will carry 20 marks.
3) The second term-end exam will carry 40 marks.
EVALUATION
Students of class IX and X will be evaluated on a 9-point grading system. Each grade, given on the basis of both formative and summative assessments, will correspond to a range of marks as indicated below :
MARKS RANGEGRADEGRADE POINT
91-100A110.0
81 -90A29.0
71 -80B18.0
61-70B27.0
51 -60C16.0
41 -50C25.0
33-40D4.0
21-32E1
00-20E2
Points to Remeber :
(i) Assessment of theory/practical papers in external subjects shall be in numerical scores.In addition to numerical scores, the Board shall indicate grades in the marks sheets issued to the candidates in case of subjects of external examinations. In case of internal assessment subjects, only grades shall be shown.
(ii) Subjects of internal examination in Class X the assessment shall be made on a five point scale I.e. A,B,C,D & E.
(iii) The grades shall be derived from scores in case of subjects of external examination. In case of subjects of internal assessment, they shall be awarded by the schools.
(iv) The qualifying marks in each subject of external examination shall be 33% . However at Senior School Certificate Examination,in a subject involving practical work, a candidate must obtain 33% marks in the theory and 33% marks in the practical separately in addition to 33% marks in aggregate, in order to qualify in that subject.
Important :
(a) In case of a tie, all the students getting the same score, will get the same grade. If the number of students at a score point need to be divided into two segments, the smaller segment will go with the larger.
(b) Method of grading will be used in subjects where the number of candidates who have passed is more than 500.
(c) In respect of subjects where total number of candidates passing in a subject is less than 500, the grading would be adopted on the pattern of grading and distribution in other similar subjects.
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Chemistry Project on Estimation of Content of Bone Ash : Class 10th CBSE


Bone Ash

ESTIMATION OF CONTENT OF BONE ASH
PROJECT SUBMITTED BY
Prashanth.G
12 D
ROLL NO:0000000000000000
Department of Chemistry
Bonafide Certificate
This is to certify that the Chemistry project __________________________
__________________________________________ in Chemistry had been
Submitted by the candidate _________________________________
With roll number   __________________ for the class XII practical examination of
the Central Board of Secondary Education in the year 2009.
It is further certified that this project is the individual work of the
Candidate.
Signature:                                                                                            Date:


ACKNOWLEDGEMENT:
I thank the staff of the Chemistry department for the help
And guidance provided to me in completing the project in
Chemistry. I also thank the principal for permitting the use of the
Resources of the school for completing the project.
Name of the Candidate:
Roll Number:
Date:
INDEX
CONTENTSPAGE NO
Bone – Introdution6
Functions7
Characteristics8
Cellular Structure10
Molecular Structure11
Types of Bones13
Formation14
Re-Modelling16
Paracrine Cell Signalling17
Experiment Analysis18
Report of the project19
Results20
Disorders21
Osteology22
Terminology23,24
Bibliography25
Abstract
This project introduces some knowledge about the basics involved in finding the constituents of bone. This Project deals with the principle of qualitative analysis of cation and anion.
Skeletal system plays an integral part of most of the animals what is that it makes it form an integral part? The solution of this can be understood more clearly from this project.
Significance of project:
  • Deals with analysis of bone ash
  • Provides all basic ideas about concentration of various salts present
  • Provides information about ion exchange reaction
This project indeed would be a revolution in the world where there is increasing worry about problems of bone like osteoporosis and in this industrial age amount of calcium content in bone is also reducing; this project would indeed be a very good solution.
Bone
.
Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Because bones come in a variety of shapes and have a complex internal and external structure they are lightweight, yet strong and hard, in addition to fulfilling their many other functions. One of the types of tissue that makes up bone is the mineralized osseous tissue, also called bone tissue, that gives it rigidity and a honeycomb-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum and periosteum, nerves, blood vessels and cartilage. There are 206 bones in the adult human body and 270 in an infant
Functions
Bones have eleven main functions:
Mechanical
  • Protection — Bones can serve to protect internal organs, such as the skull protecting the brain or the ribsheart and lungs.protecting the
  • Shape — Bones provide a frame to keep the body supported.
  • Movement — Bones, skeletal muscles, tendons, ligaments and joints function together to generate and transfer forces so that individual body parts or the whole body can be manipulated in three-dimensional space. The interaction between bone and muscle is studied in biomechanics.
  • Sound transduction — Bones are important in the mechanical aspect of overshadowed hearing.
  • Blood production — The marrow, located within the medullary cavity of long bones and interstices of cancellous bone, produces blood cells in a process called haematopoiesis.
Synthetic
Metabolic
  • Mineral storage — Bones act as reserves of minerals important for the body, most notably calciumphosphorus.and
  • Growth factor storage — Mineralized bone matrix stores important growth factors such as insulin-like growth factors, transforming growth factor, bone morphogenetic proteins and others.
  • Fat Storage — The yellow bone marrow acts as a storage reserve of fatty acids.
  • Acid-base balance — Bone buffers the blood against excessive pH changes by absorbing or releasing alkaline salts.
  • Detoxification — Bone tissues can also store heavy metals and other foreign elements, removing them from the blood and reducing their effects on other tissues. These can later be gradually released for excretion.
  • Endocrine organ – Bone controls phosphate metabolism by releasing fibroblast growth factor – 23 (FGF-23), which acts on kidneys to reduce phosphate re absorption.
Characteristics
The primary tissue of bone, osseous tissue, is a relatively hard and lightweight composite material, formed mostly of calcium phosphate in the chemical arrangement termed calcium hydroxylapatite (this is the osseous tissue that gives bones their rigidity). It has relatively high compressive strength but poor tensile strength of 104-121 MPa, meaning it resists pushing forces well, but not pulling forces. While bone is essentially brittle, it does have a significant degree of elasticity, contributed chiefly by collagen. All bones consist of living and dead cells embedded in the mineralized organic matrix that makes up the osseous tissue.
Individual bone structure
Bone is not a uniformly solid material, but rather has some spaces between its hard elements.
Compact bone or (Cortical bone)
The hard outer layer of bones is composed of compact bone tissue, so-called due to its minimal gaps and spaces. This tissue gives bones their smooth, white, and solid appearance, and accounts for 80% of the total bone mass of an adult skeleton. Compact bone may also be referred to as dense bone.
Trabecular bone
Filling the interior of the bone is the trabecular bone tissue (an open cell porousnetwork also called cancellous or spongy bone), which is composed of a network of rod- and plate-like elements that make the overall organ lighter and allowing room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten times the surface area of compact bone. If for any reason there is an alteration in the strain to which the cancellous subjected there is a rearrangement of the trabeculae. Although adult bone exists in both cancellous and compact forms, there is no microscopic difference between the two.
Cellular structure
There are several types of cells constituting the bone;
  • Osteoblasts are mononucleate bone-forming cells that descend from osteoprogenitor cells. They are located on the surface of osteoid seams and make a protein mixture known as osteoid, which mineralizes to become bone. The osteiod seam is a narrow region of newly formed organic matrix, not yet mineralized, located on the surface of a bone. Osteoid is primarily composed of Type I collagen. Osteoblasts also manufacture hormones, such as prostaglandins, to act on the bone itself. They robustly produce alkaline phosphatase, anenzyme that has a role in the mineralisation of bone, as well as many matrix proteins. Osteoblasts are the immature bone cells.
  • Bone lining cells are essentially inactive osteoblasts. They cover all of the available bone surface and function as a barrier for certain ions.
  • Osteocytes originate from osteoblasts that have migrated into and become trapped and surrounded by bone matrix that they themselves produce. The spaces they occupy are known as lacunae. Osteocytes have many processes that reach out to meet osteoblasts and other osteocytes probably for the purposes of communication. Their functions include to varying degrees: formation of bone, matrix maintenance and calcium homeostasis. They have also been shown to act as mechano-sensory receptors — regulating the bone’s response to stress and mechanical load. They are mature bone cells.
  • Osteoclasts are the cells responsible for bone resorption (remodeling of bone to reduce its volume). Osteoclasts are large, multinucleated cells located on bone surfaces in what are called Howship’s lacunae or resorption pits. These lacunae, or resorption pits, are left behind after the breakdown of the bone surface. Because the osteoclasts are derived from a monocyte stem-cell lineage, they are equipped withphagocytic-like mechanisms similar to circulating macrophages. Osteoclasts mature and/or migrate to discrete bone surfaces. Upon arrival, active enzymes, such as tartrate resistant acid phosphatase, are secreted against the mineral substrate.
Molecular structure
Matrix
The majority of bone is made of the bone matrix. It has inorganic and organic parts. Bone is formed by the hardening of this matrix entrapping the cells. When these cells become entrapped from osteoblasts they become osteocytes.
Inorganic
The inorganic is mainly crystalline mineral salts and calcium, which is present in the form of hydroxyapatite. The matrix is initially laid down as unmineralised osteoid (manufactured by osteoblasts). Mineralisation involves osteoblasts secreting vesicles containing alkaline phosphatase. This cleaves the phosphate groups and acts as the foci for calcium and phosphate deposition. The vesicles then rupture and act as a centre for crystals to grow on.
Organic
The organic part of matrix is mainly composed of Type I collagen. This is synthesised intracellularly as tropocollagen and then exported, forming fibrils. The organic part is also composed of various growth factors, the functions of which are not fully known. Factors present includeglycosaminoglycans, osteocalcin, osteonectin, bone sialo protein, osteopontin and Cell Attachment Factor. One of the main things that distinguishes the matrix of a bone from that of another cell is that the matrix in bone is hard.
Woven or lamellar
Two types of bone can be identified microscopically according to the pattern of collagen forming the osteoid (collagenous support tissue of type I collagen embedded in glycosaminoglycan gel
1) woven bone characterised by haphazard organisation of collagen fibers and is mechanically weak, and
2) lamellar bone which has a regular parallel alignment of collagen into sheets (lamellae) and is mechanically strong.
Woven bone is produced when osteoblasts produce osteoid rapidly which occurs initially in all fetalbones (but is later replaced by more resilient lamellar bone). In adults woven bone is created afterfractures or in Paget’s disease. Woven bone is weaker, with a smaller number of randomly oriented collagen fibers, but forms quickly; it is for this appearance of the fibrous matrix that the bone is termedwoven. It is soon replaced by lamellar bone, which is highly organized in concentric sheets with a much lower proportion of osteocytes to surrounding tissue. Lamellar bone, which makes its first appearance in the fetus during the third trimester,[3] is stronger and filled with many collagen fibers parallel to other fibers in the same layer (these parallel columns are called osteons). In cross-section, the fibers run in opposite directions in alternating layers, much like in plywood, assisting in the bone’s ability to resist torsion forces. After a fracture, woven bone forms initially and is gradually replaced by lamellar bone during a process known as “bony substitution.”
These terms are histologic, in that a microscope is necessary to differentiate between the two.
Types
There are five types of bones in the human body: long, short, flat, irregular and sesamoid.
  • Long bones are characterized by a shaft, the diaphysis, that is much greater in length than width. They are comprised mostly of compact bone and lesser amounts of marrow, which is located within the medullary cavity, and spongy bone. Most bones of the limbs, including those of the fingers and toes, are long bones. The exceptions are those of the wrist, ankleand kneecap.
  • Short bones are roughly cube-shaped, and have only a thin layer of compact bone surrounding a spongy interior. The bones of the wrist and ankle are short bones, as are thesesamoid bones.
  • Flat bones are thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the skull are flat bones, as is thesternum.
  • Irregular bones do not fit into the above categories. They consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated. The bones of the spinehips are irregular bones.and
  • Sesamoid bones are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the leverage of the muscle is increased. Examples of sesamoid bones are the patella and the pisiform.Compared to woven bone , lamellar bone formation takes place more slowly. The orderly deposition of collagen fibers restricts the formation of osteoid to about 1 to 2 ┬Ám per day.
Lamellar bone requires a relatively flat surface to lay the collagen fibers in parallel or concentric layers.
Formation
The formation of bone during the fetal stage of development occurs by two processes: Intramembranous ossification and endochondral ossification.
Intramembranous ossification
Intramembranous ossification mainly occurs during formation of the flat bones of the skull; the bone is formed from mesenchyme tissue. The steps in intramembranous ossification are:
  1. Development of ossification center
  2. Calcification
  3. Formation of trabeculae
  4. Development of periosteum
Endochondral ossification
Endochondral ossification, on the other hand, occurs in long bones, such as limbs; the bone is formed from cartilage. The steps in endochondral ossification are:
  1. Development of cartilage model
  2. Growth of cartilage model
  3. Development of the primary ossification center
  4. Development of the secondary ossification center
  5. Formation of articular cartilage and epiphyseal plate
Endochondral ossification begins with points in the cartilage called “primary ossification centers.” They mostly appear during fetal development, though a few short bones begin their primary ossification after birth. They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Secondary ossification occurs after birth, and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphysis and both epiphyses of a long bone are separated by a growing zone of cartilage (the epiphyseal plate). When the child reaches skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure).
Bone marrow
Bone marrow can be found in almost any bone that holds cancellous tissue. In newborns, all such bones are filled exclusively with red marrow, but as the child ages it is mostly replaced by yellow, or fatty marrow. In adults, red marrow is mostly found in the marrow bones of the femur, the ribs, the vertebrae and pelvic bones.
Remodeling
Remodeling or bone turnover is the process of resorption followed by replacement of bone with little change in shape and occurs throughout a person’s life. Osteoblasts and osteoclasts, coupled together via paracrine cell signalling, are referred to as bone remodeling units.
Purpose
The purpose of remodeling is to regulate calcium homeostasis, repair micro-damaged bones (from everyday stress) but also to shape and sculpture the skeleton during growth.
Calcium balance
The process of bone resorption by the osteoclasts releases stored calcium into the systemic circulation and is an important process in regulating calcium balance. As bone formation actively fixes circulating calcium in its mineral form, removing it from the bloodstream, resorption actively unfixes it thereby increasing circulating calcium levels. These processes occur in tandem at site-specific locations.
Repair
Repeated stress, such as weight-bearing exercise or bone healing, results in the bone thickening at the points of maximum stress (Wolff’s law). It has been hypothesized that this is a result of bone’s piezoelectric properties, which cause bone to generate small electrical potentials under stress.[4]
Paracrine cell signalling
The action of osteoblasts and osteoclasts are controlled by a number of chemical factors which either promote or inhibit the activity of the bone remodelling cells, controlling the rate at which bone is made, destroyed or changed in shape. The cells also use paracrine signalling to control the activity of each other.
Osteoblast stimulation
Osteoblasts can be stimulated to increase bone mass through increased secretion of osteoid and by inhibiting the ability of osteoclasts to break down osseous tissue.
Bone building through increased secretion of osteoid is stimulated by the secretion of growth hormone by the pituitary, thyroid hormone and the sex hormones (estrogens and androgens). These hormones also promote increased secretion of osteoprotegerin.[5] Osteoblasts can also be induced to secrete a number of cytokines that promote reabsorbtion of bone by stimulating osteoclast activity and differentiation from progenitor cells. Vitamin D, parathyroid hormone and stimulation from osteocytes induce osteoblasts to increase secretion of RANK-ligand and interleukin 6, which cytokines then stimulate increased reabsorbtion of bone by osteoclasts. These same compounds also increase secretion ofmacrophage colony-stimulating factor by osteoblasts, which promotes the differentiation of progenitor cells into osteoclasts, and decrease secretion of osteoprotegerin.
Osteoclast inhibition
The rate at which osteoclasts resorb bone is inhibited by calcitonin and osteoprotegerin. Calcitonin is produced by parafollicular cells in thethyroid gland, and can bind to receptors on osteoclasts to directly inhibit osteoclast activity. Osteoprotegerin is secreted by osteoblasts and is able to bind RANK-L, inhibiting osteoclast stimulation.
Experimental Analysis
Materials Required
PARTICULARSQUANTITY
Rib Bone2 Pieces
Beaker150 ml
Test Tube7 nos
Evaporating Dish1 no
Ring Stand1 no
Bunsen Burner1 no
Test Tube Holder2 nos
Filter Paper-
PH Paper-
Dil. Nitric Acid200 ml
1% Ammonium Hydroxide100 ml
1% Silver Nitrate25 ml
1% Ammonium Chloride50 ml
Acetic Acid100 ml
1% Potassium Thiocyanate25 ml
Distilled WaterAs Reqd
Report of Project
EXPERIMENTOBSERVATION
  • A strip of bone was burnt in evaporating dish
Yellowish white precipitate was obtained
  • 2 gms of bone as was weighed
  • To it dilute nitric acid was added
On adding Nitric acid the ash sparingly dissolved
  • It was diluted with water and the ash was completely dissolved
  • The above solution was filtered and the residue (left on the filter paper) was discarded
  • Ammonium hydroxide was added to the filtrate (left on the beaker)
The pH was made to 8.6Whitish brown precipitate of Magnesium ammonium phosphate was obtained
  • The solution was made basic. The basicity was checked with the help of pH paper
  • The solution was filtered and the residue was isolated
  • The filtrate was separated into two test tubes
White precipitate of Silver chloride was obtained
  • Silver nitrate was added to one of the test tubes
White residue of calcium
  • To the other test tube ammonium chloride and ammonium carbonate was added simultaneously and boiled
Carbonate was obtained
  • To the solution left, dilute HCL was added followed by Potassium thiocyanate
Red colour solution marking the presence of Iron was obtained
Result
Extrapolation from the above observations
Constituents of bone ash identified were:
  1. I. Calcium
  2. II. Phosphate
  3. III. Chloride
  4. IV. Magnesium
  5. V. Iron
Apart from this Calcium and Phosphate which is found maximum in bone was estimated from the precipitate got. This was done by weighing the precipitate
  • Weight of Calcium carbonate:-                                               1.7 g
  • Weight of Mg (NH4) PO4 :-                                                     1.1 g
  • Weight of Ca in 2g of sample:-                                            0.68 g
  • Weight of Phosphorous:-                                                    0.24 g
  • % of Ca:-                                                                                34%
  • % of Phosphorous:-                                                             12%
Disorders
There are many disorders of the skeleton. One of the more prominent is osteoporosis.
Osteoporosis
Osteoporosis is a disease of bone, leading to an increased risk of fracture. In osteoporosis, the bone mineral density (BMD) is reduced, bone microarchitecture is disrupted, and the amount and variety of non-collagenous proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old sex-matched healthy person average) as measured by DXA; the term “established osteoporosis” includes the presence of a fragility fracture.[6] Osteoporosis is most common in women after the menopause, when it is called postmenopausal osteoporosis, but may develop in men and premenopausal women in the presence of particular hormonal disorders and other chronic diseases or as a result of smoking and medications, specifically glucocorticoids, when the disease is called steroid-or glucocorticoid-induced osteoporosis (SIOP or GIOP).
Osteoporosis can be prevented with lifestyle advice and medication, and preventing falls in people with known or suspected osteoporosis is an established way to prevent fractures. Osteoporosis can be treated with bisphosphonates and various other medical treatments.
Other
Other disorders of bone include:
  • Bone fracture
  • Osteomyelitis
  • Osteosarcoma
  • Osteogenesis imperfecta
  • Osteochondritis Dissecans
  • Bone Metastases
  • Neurofibromatosis type I
Osteology
The study of bones and teeth is referred to as osteology. It is frequently used in anthropology, archeology and forensic science for a variety of tasks. This can include determining the nutritional, health, age or injury status of the individual the bones were taken from. Preparing fleshed bones for these types of studies can involve maceration – boiling fleshed bones to remove large particles, then hand-cleaning.
Typically anthropologists and archeologists study bone tools made by Homo sapiens and Homo neanderthalensis. Bones can serve a number of uses such as projectile points or artistic pigments, and can be made from endoskeletal or external bones such as antler or tusk.
Alternatives to bony endoskeletons
There are several evolutionary alternatives to mammillary bone; though they have some similar functions, they are not completely functionally analogous to bone.
  • Exoskeletons offer support, protection and levers for movement similar to endoskeletal bone. Different types of exoskeletons include shells,carapaces (consisting of calcium compounds or silica) and chitinous exoskeletons.
  • A true endoskeleton (that is, protective tissue derived from mesoderm) is also present in Echinoderms. Poriferaspicules and a spongin fiber network.(sponges) possess simple endoskeletons that consist of calcareous or siliceous
Exposed bone
Bone penetrating the skin and being exposed to the outside can be both a natural process in some animals, and due to injury:
  • A deer’s antlers are composed of bone.
  • Instead of teeth, the extinct predatory fish Dunkleosteus had sharp edges of hard exposed bone along its jaws.
  • A compound fracture occurs when the edges of a broken bone puncture the skin.
  • Though not strictly speaking exposed, a bird’s beak is primarily bone covered in a layer of keratin over a vascular layer containing blood vessels and nerve endings.
Terminology
Several terms are used to refer to features and components of bones throughout the body:
Bone featureDefinition
articular processA projection that contacts an adjacent bone.
articulationThe region where adjacent bones contact each other — a joint.
canalA long, tunnel-like foramen, usually a passage for notable nerves or blood vessels.
condyleA large, rounded articular process.
crestA prominent ridge.
eminenceA relatively small projection or bump.
epicondyleA projection near to a condyle but not part of the joint.
facetA small, flattened articular surface.
foramenAn opening through a bone.
fossaA broad, shallow depressed area.
foveaA small pit on the head of a bone.
LabyrinthA cavity within a bone.
lineA long, thin projection, often with a rough surface. Also known as a ridge.
malleolusOne of two specific protuberances of bones in the ankle.
meatusA short canal.
processA relatively large projection or prominent bump.(gen.)
ramusAn arm-like branch off the body of a bone.
sinusA cavity within a cranial bone.
spineA relatively long, thin projection or bump.
sutureArticulation between cranial bones.
trochanterOne of two specific tuberosities located on the femur.
tubercleA projection or bump with a roughened surface, generally smaller than a tuberosity.
tuberosityA projection or bump with a roughened surface.
Bibliography
  • Biology Investigations
-        Otto, Towle, Crider
  • Concise Inorganic Chemistry
-        J.D.Lee
  • Wikipedia
  • NCERT Biology and chemistry Textbook
  • The Journal of Biological Chemistry
-        Anon
READ MORE - Chemistry Project on Estimation of Content of Bone Ash : Class 10th CBSE

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