Sunday 1 November 2015

Reproduction

Reproduction is a biological process in which organisms produces their own kind of individuals. Reproduction is the most typical character of living beings. In other words it is the process in which species maintains their survival on this earth by producing the young ones of the same species.

Purpose of reproduction:-
i) Reproduction maintains the continuity of species.
ii) It is the process in which any population able to maintain the young, adults and aged individuals.
iii) Reproduction helps to bring the variations among any specie which helps that specie for adaptation and evolution for changing surrounding conditions.
iv) Life is possible on this earth because of reproduction.

Types of Reproduction:- Basically there are two types of reproduction found in the living organisms. These are
   
               a) Asexual Reproduction
               b) Sexual Reproduction

a) Asexual Reproduction:- It is the reproduction in which there is only single parent involved in the process or without the fusion of male and female gametes ( involvement of male and female gametes occurs in the sexual reproduction). In this type the organisms produced will be the exact copies of parent.  These individuals are called clones because they are genetically and morphologically similar to their parent.
Main features of asexual Reproduction
i) There will be a single parent.
ii) There will not be a gamete formation.
iii) fertilisation will be absent.
iv) No meiosis will takes place only mitosis will be present.
v) Because there is no fusion of the gametes of two different parents so no variation or daughter individuals are genetically identical to the parent.
vi) Multiplication occurs rapidly.

Asexual reproduction is normally the character of unicellular organisms like monerans and protists and in plants and in certain animals.

b) Sexual reproduction:- It is a reproduction in which new individuals are formed through the formation and fusion of male and female gametes. This process is also called amphimixis ( both parents's gametes are mixing together). Actually sexual reproduction has four main steps:-

i) Formation of gametes through the division of meiosis. this is called gametogenesis or this is the formation of haploid cells. ( 1N )
ii) Fusion of two gametes forming the diploid cell ( 2N ) zygote. This fusion is called fertilisation.
iii) Repeated mitotic divisions of zygote for the formation of embryo.
iv) Growth of the embryo into full individual.

Main features of Sexual reproduction:-
i) Two parents are involved therefor, it is usually biparental.
ii) There is always formation of gametes.
iii) It involves both meiosis and mitosis.
iv) New individuals formed will be different from their parents.
iv) Multiplication is not so rapid as in case of sexual reproduction.











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