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OBJECTIVES After studying this unit, you will beable to Chemistry is the science of molecules and theirtransformations. It is the science not so much of the onehundred elements but of the infinite variety of molecules thatmay be built from them.Roald Hoffmann Science can be viewed as a continuing human effort tosystematise knowledge for describing and…

CONTENTSForeword iiiUnit 1 Some Basic Concepts of Chemistry 11.1 Importance of Chemistry 41.2 Nature of Matter 41.3 Properties of Matter and their Measurement 61.4 Uncertainty in Measurement 101.5 Laws of Chemical Combinations 141.6 Dalton’s Atomic Theory 161.7 Atomic and Molecular Masses 161.8 Mole Concept and Molar Masses 181.9 Percentage Composition 181.10 Stoichiometry and Stoichiometric Calculations…

22.1 EndocrineGlands andHormones22.2 HumanEndocrineSystem22.3 Hormones ofHeart, KidneyandGastrointestinalTract22.4 Mechanism ofHormone Action You have already learnt that the neural system provides apoint-to-point rapid coordination among organs. The neuralcoordination is fast but short-lived. As the nerve fibres do not innervateall cells of the body and the cellular functions need to be continuouslyregulated; a special kind of coordination and…

21.1 Neural System21.2 Human NeuralSystem21.3 Neuron asStructural andFunctional Unitof NeuralSystem21.4 Central NeuralSystem21.5 Reflex Actionand Reflex Arc21.6 SensoryReception andProcessing As you know, the functions of the organs/organ systems in our bodymust be coordinated to maintain homeostasis. Coordination is theprocess through which two or more organs interact and complement thefunctions of one another. For example, when we…

20.1 Types ofMovement20.2 Muscle20.3 Skeletal System20.4 Joints20.5 Disorders ofMuscular andSkeletal System Movement is one of the significant features of living beings. Animals andplants exhibit a wide range of movements. Streaming of protoplasm inthe unicellular organisms like Amoeba is a simple form of movement.Movement of cilia, flagella and tentacles are shown by many organisms.Human beings can…

19.1 HumanExcretorySystem19.2 Urine Formation19.3 Function of theTubules19.4 Mechanism ofConcentration ofthe Filtrate19.5 Regulation ofKidney Function19.6 Micturition19.7 Role of otherOrgans inExcretion19.8 Disorders of theExcretorySystem Animals accumulate ammonia, urea, uric acid, carbon dioxide, waterand ions like Na+, K+, Cl–, phosphate, sulphate, etc., either by metabolicactivities or by other means like excess ingestion. These substances haveto be removed totally…

18.1 Blood18.2 Lymph (TissueFluid)18.3 CirculatoryPathways18.4 DoubleCirculation18.5 Regulation ofCardiac Activity18.6 Disorders ofCirculatorySystem You have learnt that all living cells have to be provided with nutrients, O2and other essential substances. Also, the waste or harmful substancesproduced, have to be removed continuously for healthy functioning oftissues. It is therefore, essential to have efficient mechanisms for themovement of these…

17.1 RespiratoryOrgans17.2 Mechanism ofBreathing17.3 Exchange ofGases17.4 Transport ofGases17.5 Regulation ofRespiration17.6 Disorders ofRespiratorySystem As you have read earlier, oxygen (O2) is utilised by the organisms toindirectly break down simple molecules like glucose, amino acids, fattyacids, etc., to derive energy to perform various activities. Carbon dioxide(CO2) which is harmful is also released during the above catabolicreactions. It…

16.1 DigestiveSystem16.2 Digestion ofFood16.3 Absorption ofDigestedProducts16.4 Disorders ofDigestiveSystem Food is one of the basic requirements of all living organisms. The majorcomponents of our food are carbohydrates, proteins and fats. Vitaminsand minerals are also required in small quantities. Food provides energyand organic materials for growth and repair of tissues. The water we takein, plays an important…

15.1 Growth15.2 Differentiation,DedifferentiationandRedifferentiation15.3 Development15.4 Plant GrowthRegulators15.5 Photoperiodism15.6 Vernalisation You have already studied the organisation of a flowering plant in Chapter 15.1 GROWTHGrowth is regarded as one of the most fundamental and conspicuouscharacteristics of a living being. What is growth? Growth can be definedas an irreversible permanent increase in size of an organ or its parts…