REPRODUCTION IN ORGANISMS .PART 5
 POST FERTILISATION  EVENTS.
E vents in sexual reproduction after the formation of zygote(2n)

in external fertilisation zygote formedd in external medium
in  internal fertilisation zygote formed inside the body of female organism.
In ALGAE and FUNGI  zygote Develops a thick wall resistant to dessication and damage 
and undergoes a period of rest before germination.

IN HAPLONTIC  Organisms zygote undergoes meiosis 
  IN DIPLONTIC  organisms zygote underggoes mitosis 

EMBRYOGENESIS  - process of Development of embryo from zygote , by celldivision and cell differentiation

OVIPAROUS    deveopment of zygote outside the body of female parent .(lie eggs )
-after incubation young ones hatch out  eg reptile , birds 
VIVIPAROUS development of zygote inside the female parent 
- after attaining certaiin period of growth young ones are delivered
- get proper embryonic care and protection  o chances of survival more .

in FOWERING PLANTS
ZYGOTE- EMBRYO 
OVULE - SEED
OVARY - FRUIT 

REPRODUCTION  IN ORGANISMS ..part 4
GAMETE TRANSFER- male gamete and female gamete physically brought together for fusion.
IN most of the cases male gametes are motile and female stationary
no of male gametes are more to compensate loss during transport
IN SEED PLANTS -pollen grains contain male gametes ,and ovule contain egg 
POLLINATION - transfer of polengrains from anther to stigma.
pollengrains germinate on stigma,pollen tube carrying male gametes reach the ovule and discharge near to egg.
FERTILISATION - fusion of male and female gametes resulting in the formation of zygote
PARTHENOGENESIS - female gamete develop into new organism without fertilisation.
eg lizard , rotifers honey bees turkey 

EXTERNAL FERTILISATION -  syngamy occurs in external medium
 'great ynchrony between sexes 
 - release large no of gametes in to the medium to enhance the chance of syngamy

 Dis advantage - offsprings are threatened by predators  eg frog , bony fishes

INTERNAL FERTILISTION- syngamy occurs inside the body of female organism.
fungi,repties , birds ,mammals,bryophytes , pteriophytes , gymnosperms and angiosperms 
- egg formed in female body  , no of eggs less ,male gametes motille andd more in no 
in angioperms male gametes non motile and carried to egg by pollen tube.

EASY BOTANY TASTY BOTANY -a magic botanical touch 

REPRODUCTION IN ORGANISMS  part 3  prefertilisation
events of sexual reproduction prior to fuion of gametes, includes gametogenesis  and gamete transfer.
GAMETOGENESIS- process of formation of haploid male and female gametes.
HOMOGAMETES-gametes simillar in appearance.
HETEROGAMETES- gametes dissimilar in appearance .(male- antherozoid /sperm;female egg /ovum)
BISEXUAL,/ MONOECIUS /HOMOTHALLIC     /
HERMAPHRODITE (ANIMALS like earth worm ,leech ,tape worm , sponge )male and female reproductive strucures on  same organism.eg  cucurbits ,coconut .
UNISEXUAL/DIOECIUS  / HETROTHALLIC . male and female reproductive structures on Different organisms. eg papaya,  date palm , marchantia , cockroach .
unisexual male flower - staminate , unisexual female flower - pistillate 
CELL DIVISION DURING GAMETE FORMATION 
gametes are haploid   in haploid plants (algae , fungi, bryophytes)  gametes produced by MITOSSIS.
in diploid organisms specialised cells known as meiocytes or gamete mother are produced  which undergoes MEIOSIS and produces haploid gametes.