Presentation on theme: "Flower Structure Objectives:"— Presentation transcript:
1 Flower Structure Objectives: *State the functions of different parts of a flower**Describe the structures of insect and wind pollinated flowers*** Compare the adaptations of flowers and pollens of insect and wind pollinated flowers
3 SepalPetalStamenCarpelMale organ. Anther is where the pollens Pollen is the male sex cell (gamete).are made and the filament holds up the anther so the flowers can be pollinated easilyFemale organ. Ovary contains the ovule s which has female gametes. Stigma is where the pollen lands, style connects the ovary to the stigmaBright colour and scent for attracting pollinating agents Many have nectary at base to make nectar for feeding insects.Protects the flower in bud
4 Insect pollinatedWind pollinatedPetalsNectariesStamenPollenCarpelsLarge brightly coloured and scented to attract insectsSmall, green inconspicuous flowers , no scentProduces sugary nectar to attract insectsNo nectaryAnthers inside so insects can rub against themAnthers hang outside so wind can blow away large quantities of pollenSticky, spikey,Made in large quantity as a lot can get wasted, smooth and lightFeathery long stigma positioned outside the flower which act as nets to catch as much pollen as possibleSticky short stigma positioned inside the flower for insects to rub against it.
5 PollinationObjectives: *Define self and cross pollination **Name agents of pollination *** Discuss significance of self and cross pollination
6 Sexual reproduction in flowers Pollination occurs when pollen grains from the stamen land on the stigma of the carpelFertilisation occurs when the male sex cell in the pollen fuses with the female sex cell in the ovuleSexual reproduction in flowers
8 Self PollinationCross PollinationAdvantagesNo pollinating insects neededPlants growing in isolation from others of the same species can still get pollinatedWell adapted to the same environment as their parentsPollination is more successfulVariation due to exchange of genetic materialDispersed away from each other leading to no intraspecific competitionWell adapted to change in environment due to variation upon which natural selection can operateWell suited for evolutionDisadvantagesVery little variation unless there is a mutation which may not be expressedVery limited chance of evolutionIntraspecific competitionDependant on pollinating insectsPlants in isolation will not be able to reproducePollination is a question of chance