reproduction in plants

• label the parts of an insect pollinated plant: 1) stigma 2)style 3) ovule 4) ovary 5) sepal 6) receptacle 7) anther 8) filament 9) petal

  
• what is the function of the sepal: usually the outermost layer, modified leaves which enclosed & protect other flower parts in the bud
• what is the function of petals: make up the corolla and are modified leaves, brightly coloured in insect-pollinated flowers. landing platform for insects
• what is the function of anthers: produces pollen grains which has two nuclei— generative nucleus & pollen tube nucleus
• what is the function of carpels: made up of stigma, style, ovary & ovules. female part of the flower
• what is the function of stigma: swollen structure at the end of the style. sugary fluid secreted by mature stigma to stimulate germination
• what is the function of style: stalk that connects stigma and ovary. holds it in a suitable position to trap pollen grains
• what is the function of ovary: each mature ovule is an ovum (haploid) attached to the placenta by funicle
• what is pollination: transfer of pollen grains from the anther to the stigma of a flower on a plant
• self-pollination VS cross-pollination: pollen grains are transferred to the stigma of the same flower or a different flower in the same plant VS pollen grains are transferred to a flower in another plant of the same kind
• process of pollen tube & fertilisation: aft poll., pollen tube grows out from pollen grain-stimulated by the sugary fluid secreted by the mature stigma. cytoplasm of a pollen tube has two nuclei: pollen tube nucleus & generative nucleus. enzymes are secreted to digest the tissues of the stigma & style. pollen tube penetrates through the style & enters the embryo sac of the ovule, through the micropyle
• process of pollen tube & fertilisation (PART 2): generative cell divides to form 2 male gametes. pollen tube cell disintegrates before reaching embryo sac. within the ovule, the tip of the pollen tube absorbs sap and bursts, releasing the two male gametes.