GYMNOSPERMS AND CONES
Gymnosperms produce pollen and eggs in structures called cones. Pollen cones have two microsporangia at the base of each sporophyll, or scale. Meiosis occurs in the microsporangia to produce microspores, which develop into pollen. Pollen represents the immature male gametophyte stage of gymnosperms. A pollen grain will eventually produce sperm nuclei for fertilization of the egg. Pollination, the process of pollen transfer to the site of the egg, is typically via wind. Because the sperm nuclei are carried to the egg within the pollen grain, there is no requirement for water in the fertilization process. Although wind pollination does away with the need for water, it is still a relatively chancy process; therefore, gymnosperms produce large amounts of pollen.