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www.GOALias.blogspot.comActivity 12.4Take a mustard/china rose/petuniaflower and separate its reproductiveparts. Study the various parts of astamen and pistil.The flowers which contain eitheronly the pistil or only the stamens arecalled unisexual flowers. The flowerswhich contain both stamens and pistilare called bisexual flowers. Corn,papaya and cucumber produceunisexual flowers, whereas mustard,rose and petunia have bisexual flowers.Both the male and the female unisexualflowers may be present in the same plantor in different plants.Could you identify the anther andthe filament of a stamen? [Fig. 12.9 (a)].Anther contains pollen grains whichproduce male gametes. A pistil consistsof stigma, style and ovary. The ovarycontains one or more ovules. Thefemale gamete or the egg is formed inan ovule [Fig. 12.9 (b)]. In sexualreproduction a male and a femalegamete fuse to form a zygote.AntherBoojho wants to know how themale gamete in the pollen grainreaches the female gamete presentin the ovule.Stigma(a) StamenFilamentStigmaPollinationGenerally pollen grains have a toughprotective coat which prevents themfrom drying up. Since pollen grains arelight, they can be carried by wind orStyleOvulePollensAntherStigmaOvary(b) PistilFig. 12.9 Reproductive parts(a) Self-pollination(b) Cross-pollinationFig. 12.10 Pollination in flower137REPRODUCTIONIN PLANTS137