Reproduction in Flowering Plants

Reproduction in Flowering Plantsself - pollinationcross - pollinationwind - pollinatedFertilizationpollinationInsect pollinationadvantagesdisadvantagesadvantagesdisadvantagesthe pollen tube is then directed by the pollen tubenucleus to grow downwards towards the ovuleParts of a monocotyledonous flowercarpelsstamensstigmastyleovaryantherfilamentsepalscontains pollen sacs which containpollen grainscontains vascular bundlesupports the anther positions anther in a suitable positionfor dispersal of pollen grainssticky and swollen structure that receivespollen grains during pollinationa stalk that holds up the stigmawhere fertilization occurscontains ovules that will developinto seeds after fertilizationdevelops into fruit after fertilizationwithered or modified to help in fruitdispersal after fertilizationwithered or modified to help in fruitdispersal after fertilizationpetalsrecepTaclepedicelovulesdevelop into seedsafter fertilizationovary wallprotective layers aroundthe ovarydevelops into the fruitwall after fertilizationwithered or modified to help in fruitdispersal after fertilizationwithered or modified to help in fruitdispersal after fertilizationmodified green leaves that protect theflower bud and petalstogether they make up the calyxwithered or modified to help in fruitdispersal after fertilizationmodified leavestogether they make up the corollabrightly coloured in insect pollinated flowers;small or absent for wind pollinated oneswithered or modified to help in fruitdispersal after fertilizationenlarged end of flower stalkbears other parts of the flowerholds the flower in proper positionmature pollen grains land on a mature stigmathe pollen grain then germinates on the stigmadue to the substance secreted by itthe pollen grain then produces a pollen tubegenerative nucleus in the pollen tube divides into 2 by mitosis, forming the 2 male gametesenzymes are secreted to digest the stigma and stylethe pollen tube grows downwards, towards the ovuleand enters the ovule through the micropyleThe pollen tube bursts open and releases the 2 male gametesone of them is attracted to the egg celldue to the smell produced by the synergidsfuses with the haploid egg cell 2 form diploid embryoboth are haploid in naturethe other male gamete fuses withthe diploid central nucleus containingthe 2 polar nucleito form the triploid endosperm nucleus, which develops to form the endospermin the fruit. The endosperm provides food for the fruitfastermore likely to occurlesser genetic variation, less immune to diseasesharmful recessive alleles maybe expressed in the offspringhow it is preventedmale and female parts mature at different timesdependent on externalfactors that are neededless likely to occurmore genetic variation, offspringare more resistant to diseaseslower probability of harmful recessivealleles being expressed in offspringhave a feathery stigma that can catch pollen grains floating in the airstigma and style protruding out of the flowerpenduloussmooth, light pollen grainsstigma and style do not protrude outof the flowerthe stigma is swollen and stickyrough pollen grainsto be easily carried away by the windto stick to the insects' hairy bodies