Thursday, June 18, 2020

REPRODUCTION IN ORGANISMS  PART 2 
SEXUAL REPRODUCTION.

SEXUAL REPRODUCTION - involves  formation and fusion of male and femae gametes and their fusion resulting in the formation of zygote .zygote later develops in to embryo and new organism.
all organisms show similar pattern for exual reproduction.
JUVENILE PHASE /VEGETATIVE PHASE - phase of  growth before exual maturity in animals known as juvenile phase and in plants vegetative phase .
some plants flower seasonally  and others throughout the year.
BAMBOO flower once in their life cycle and  STROBILANTHUS KUNTHIANA (NEELAKKURUNJI)  once in 12 years

animals show morphological, physiogical  and behavioral changes prior to active reproductive behaviour
OESTRUS CYCLE - cyclical changes  during reproduction in non primate mammals like cow ,sheep, rat ,deer, dog , tiger etc 
MENSTRUAL  CYCE-  cyclical changes uring reproduction in primate mammals  like monkeys , apes and humanbeings.
SEASONAL BREEDERS - animals reproductively active only during favourabe seasons in their reproductive phase .
CONTINUOUS BREEDERS -  animals reproductively active  through out their reproductive phase.
EVENTS IN SEXUAL REPRODUCTION -1 PREFERTILISATION--- (gametogenesis and gamete transfer ) ,  2.FERTILISATION  and POSTFERTILISATION (formation of zygote , formation aof embryo))

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