Pollen - of Lilium . Pollination The transfer of pollen...

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Pollen Pollen grains (from the greek palynos for dust or pollen) contain the male gametophyte ( microgametophyte ) phase of the plant. Pollen grains are produced by meiosis of microspore mother cells that are located along the inner edge of the anther sacs (microsporangia). The outer part of the pollen is the exine , which is composed of a complex polysaccharide, sporopollenin. Inside the pollen are two (or, at most, three) cells that comprise the male gametophyte. The tube cell (also referred to as the tube nucleus) develops into the pollen tube . The germ cell divides by mitosis to produce two sperm cells. Division of the germ cell can occur before or after pollination. The tetrad of four haploid cells is located inside an anther sac (microsporangium)
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Unformatted text preview: of Lilium . Pollination The transfer of pollen from the anther to the female stigma is termed pollination. This is accomplished by a variety of methods. Entomophyly is the transfer of pollen by an insect. Anemophyly is the transfer of pollen by wind. Other pollinators include birds, bats, water, and humans. Some flowers (for example garden peas) develop in such a way as to pollinate themselves. Others have mechanisms to ensure pollination with another flower. Flower color is thought to indicate the nature of pollinator: red petals are thought to attract birds, yellow for bees, and white for moths. Wind pollinated flowers have reduced petals, such as oaks and grasses....
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Pollen - of Lilium . Pollination The transfer of pollen...

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