01:119:116 Lecture Notes - Lecture 8: Lycopodiophyta, Sorus, Sporophyte
16 Oct 2018
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Document Summary
Sporophylls are modified leaves bearing sporangia and have various forms: ferns have cluster of sporangia (sori) on underside of sporophylls, lycophytes & gymnosperms have sporophylls that form cone-like structures (strobili) Two forms of spore production exist: page 625. Phylum lycophyte: club mosses, spike mosses (called mosses but not true mosses, many are epiphytes, epiphytes plants that use other plants as substrate but not parasitic, roots only branch at growing tips (for y-shaped tip) Phylum monilophyta: ferns, horsetails and whisk ferns, have traits common with seed plants, megaphyll leaves, roots that branch at various points along existing root (not just at tips) Several adaptations in seed plants facilitated coping with drought, uv light & fertilization without water. Seeds: embryo with food supply & surrounded by protective coat. Reduced gametophyte fig 30. 2: microscopic in size, develop from spores within sporangia of parent sporophyte, completely dependent on parent sporophyte. 2/14/14: protects gametophyte from drying, and uv exposure.
