FLOWERS AS REPRODUCTIVE STRUCTURES 2 of 3.ppt
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Lorraine Kuun, July 2011 Adaptations of Salvia for insect pollination by bees Landing platform Nectar guides Tubular shape, contains nectar Stamens form “lever” Pistil overhanging landing platform Bees attracted to blue and yellow flowers
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Transcript of FLOWERS AS REPRODUCTIVE STRUCTURES 2 of 3.ppt
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Lorraine Kuun, July 2011Adaptations of Salvia for insect pollination by beesLanding platformNectar guidesTubular shape, contains nectarStamens form leverPistil overhanging landing platformBees attracted to blue and yellow flowers
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High yield of dilute nectarBigger than most insect-pollinated flowersOpen in daytime, often redSturdy against rough feeding of birdsLittle or no scent birds have poor sense of smellProtect ovary against beaks by being inferior or by partitionPollen sticks together in clumpsOften erect or with landing platform for birds that do not hover
Lorraine Kuun, July 2011Adaptations of flowers for bird pollination
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Lorraine Kuun, July 2011Adaptations of Strelitzia for pollination by birdsBright coloursNectariesSturdy landing platformStigma close to pollenStamens fused in tube to fit beak
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Lorraine Kuun, July 2011
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Lorraine Kuun, July 2011
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Lorraine Kuun, July 2011
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Flowers do not have scent, nectar or brightly coloured petals no need to attract pollinators.Flowers high on plant to be exposed to wind.Flowers usually small and reduced, lacking calyx or corolla (sepals and petals).Anthers large and well-exposed.Masses of light, non-sticky pollen produced.Stigmas long and feathery with large area for trapping pollen.
Lorraine Kuun, July 2011Adaptations for wind pollination
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Lorraine Kuun, July 2011
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Lorraine Kuun, July 2011
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The pollen grain germinates
Meiosis occurs in the pollen grain.
The male gametes are haploid.
When the ripe pollen grain lands on a receptive stigma, it will germinate.
The pollen grain germinates and form a pollen tube.
Lorraine Kuun, July 2011
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The germinated pollen grain is the male gametophyte
Lorraine Kuun, July 2011
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The female pistil The ovary contains the ovule(s) with female gametes (n). The pollen tube grows down the style, through the micropyle and into the embryo sac.Double fertilisation occurs.
Lorraine Kuun, July 2011
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The female gametophyte: germ sac with 8 nucleiLorraine Kuun, July 2011
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Lorraine Kuun, July 2011
