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Showing posts from January, 2007

Chapter 2 Cell Structure and Cell Organisation

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Cell is the basic structural and functional unit of all organisms. Robert Hook coined the term "cell" for the box like structures he found in thin sections of plant material in 1965. A cell carries out basic life activities such as respiration, excretion and digestion.The three basic components of a cell are plasma membrane, cytoplasm and nucleus. Plant and animal cells contain various types of organelles, such as nucleus, nucleolus, chromosomes,endoplasmicreticulum, mitochondria ,Golgi apparatus, lysosome, chloroplast, centriole and vacuole.Each organelle carries out its own specific function in a cell.Cells are organised in the formation of tissues, organs and systems in humans, animals and plants. Unicellular organism like the amoeba and the paramecium are aquatic and are able to carry out all the activities necessary for living. The amoeba has no fixed shape, feeds on microscopic organisms, like the diatom and bacteria.Amoeba's mode of feeding is phagocytic. Locomoti…

Chapter 1 Introduction to Biology

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Biology is the science of life.
In Latin 'bios'means life while 'logos' refers to knowledge. The study of Biology includes the study of living things, their environment as well as the interaction of living things with their environment. Fields of study and careers related to Biology include biochemistry, physiology, genetics, botany, zoology, ecology, microbiology and biotechnology. Biological studies like the other sciences emphasise on inquiry and problem solving.
Scientific skills are important in any scientific investigation like conducting experiments and carrying out projects. Scientific investigation involves the following steps:(i) Observe a situation and identify all the variables.(ii) Suggest a question that is suitable for a scientific investigation.(iii) Discuss to- form a hypothesis-plan the method of investigation including selection of apparatus and work procedures(iv) Carry out an experiment- to collect and tabulate data - present the data in a suitable …