BIO 2137 Lecture Notes - Lecture 10: Leptosporangiate Fern, Spermatophyte, Marattiidae
12 Oct 2016
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Megaphylls and microphylls = vascularization of leaf. Starts off with just one cell which divides rather than two layers. Botrichium, one leaf fern like, huge fertile portion. Psilotales: - highly modified, no roots or leaves due to reduction. (due to humidity loss) Likes damp places but can survive periods of dryness. One first come out they are fiddleheads. This is how fern mom can fee the lpetos. E(cid:374)(cid:272)apsulates the e(cid:373)(cid:271)ryo"s, i(cid:374)du(cid:272)es dor(cid:373)a(cid:374)(cid:272)y to allo(cid:449) for ti(cid:373)ed ger(cid:373)i(cid:374)atio(cid:374: pollen. With bryophytes, the gametangia and sperm are exposed. Flowering plants only produce seeds when fertilized, gymnosporems produce seeds whn thy want. Modification of apex of megasporangium to review microspore or pollen grains. In ginko, sperm (cid:449)i(cid:373)s (cid:448)ery little (cid:449)ay/ therefore you do(cid:374)"t (cid:374)eed to s(cid:449)i(cid:373) that (cid:374)u(cid:272)h. Pollination may explain diversity dependening on the animals which pollinate it. Cycadophyta and ginkophyta: pollen tube grows in nucleus like parasity. Soerm cells divide, nucleus directs pollen to egg.
