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Chapter -2 Biological classification

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  Biological classification is the scientific procedure of arranging organisms into groups and subgroups on the basis of their similarities and dissimilarities and placing the group in a hierarchy of categories. Importance of classification :-  It is not possible to study every organism. Study of one or two organism of a group gives sufficient information about the essential features of the group. It helps in identification of new organism. Classification helps in knowing the relationship amongst different groups of organisms. The organism of past cannot be studied without a proper system of classification. Classification :-  (i)Artificial system of classification (ii)Natural system of classification (iii)Phylogenetic system of classification (i)Artificial system of classification- Only one or two morphological characters for grouping of organism is used. Flowering and non-flowering plants, enaima and anaima. Aristotle classification. (ii)Natural system of classification- Takes into

Chapter 1 Reproduction in organisms

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  CHAPTER-01 REPRODUCTION IN ORGANISMS Reproduction is a biological process of formation of new offsprings from the pre-existing organism.Reproduction becomes a vital process without which species cannot survive for long It ensures continuity of species generation after generations as older individuals undergo senescence and ultimately they die. Life span  - • The period from birth to the natural death of an organism represents its  life span . Life span of organisms varies from few days (Butterfly-1to 2 weeks) to thousands of years (Banyan tree). Types of Reproduction : Based on whether there is one or two organisms taking part in the process of reproduction ASEXUAL REPRODUCTON SEXUAL REPRODUCTION When the offspring is produced by single parents with or without the involvement of gamete formation, the reproduction is called  asexual reproduction . When two parents (opposite sex) participates in reproduction process and also involves the fusion of male and female gametes, it is called