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Reproduction:
               defined as a biological process in which an organism gives rise to young ones (offspring) similar to itself.
               Asexual reproduction:
                             Offsprings produced by single parents.
                             Without involvement of gamete formation
                             Offsprings are genetically identical to their parents.
               Methods of asexual reproduction:
                             Cell division as a method of asexual reproduction as in Protista and monera.
                             Binary fission e.g. Amoeba, Paramecium.
                             Budding: e.g. yeast.
                             Asexual reproductive structures:
                                 o   Zoospores: aquatic fungi, Chlamydomonas.
                                 o   Conidia: Penicillium.
                                 o   Bud: Hydra
                                 o   Gemmules: sponges.
                             Vegetative propagation units in plant: (Vegetative propagules)
                                 o   Runner, rhizome, sucker, tuber, offset, bulb.
               Sexual reproduction:
                             Involvement of single or two individual.
                             Production of male and female gametes ( haploid)
                             Gametes fused to form a diploid zygote.
                             Zygotes developed into new organism.
                             The offsprings are not genetically identical with their parents.
               Features of sexual reproduction:
                             Period  between  birth  and  sexual  maturity  is  called juvenile  phase.  It  is  known  as vegetative
                              phase in plant.
                             Bamboo species flower only once in their life time generally after 50-100 yr.
                             Strobilanthus kunthiana (neelakranji) flowers once in 12 years.
                             Oestrus  cycle:  cyclical  changes  during  reproduction  in  non-primate  mammal  like  cows,  sheep,
                              rats, deers, dogs, tiger etc.
                             Menstrual  cycle:  cyclical  changes  during  reproduction  in  primate  mammals  like  monkeys,  ape,
                              and humans.
                             Seasonal breeders: reproductive cycle takes place in favourable seasons as in wild animals.
                             Continuous breeders: reproductively active throughout their reproductive phase.
               Pre-fertilization events:
                             Process of gamete formation is gametogenesis.
                             Two gametes are similar in appearance are called homogametes (isogametes).
                             Gametes produced are of two morphologically distinct types called heterogametes.
                             Male gamete is called antherozoids or sperm and the female gamete is called ovum or egg.
               Sexuality in organism:
                             Plant having both male and female sex organ called homothallic or monoecious.
                             Plants having only one sex organ is called heterothallic or dioecious.
                             In flowering plants, the unisexual male flower is staminate, i.e. bearing staments, while the female
                              is pistillate or bearing pistils.
                             Animal having one type of reproductive system, called unisexual.
                             Animal having both male and female reproductive system, called hermaphrodite or bisexual.
               Cell division during gamete formation:
                             Gametes in all heterogametic species two types namely male and female.
                             Gametes are always haploid irrespective of parent’s ploidy.
                             A haploid parent produces gametes by mitotic division.
                             Diploid parent produces gametes by meiotic division.
                             In diploid organisms specialized cells called meiocytes (gamete mother cell) undergo meiosis to
                              produce haploid gametes.
               Gamete transfer:
                             Male and female gamete must be physically brought together to facilitate fusion called fertilization.
                             In most cases male gametes are motile, female gametes are non-motile.
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