Unformatted text preview: are wind pollinated and many produce distinctive winged pollen. Male strobili Strobilus xs Microsporangium Pollen The female gametophyte, which develops from the megaspore, contains two or more archegonia. The surrounding megasporangial tissue is modified into the integument layers, which protect the gametophyte and eventually form the seed coat, and the nucellus layers from which the gametophyte obtains nutrients. In pines, the female gametophyte takes one year to develop after pollination. The pollen grain germinates at pollination and grows the pollen tube, but the generative cell does not form sperm until the female gametophyte is mature....
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- Fall '09
- Plants, Ovule, Pollen, Gametophyte, female gametophyte, mature pollen grain