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Seed Plants. BSC 2011L. Seed Vascular Plants. Among plants, these include the gymnosperms and angiosperms. Reproductive differences in seedless vs. seed plants. Sporangia Seed plants have 2 types: megasporangium , microsporangium Protection of egg
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Seed Plants BSC 2011L
Seed Vascular Plants • Among plants, these include the gymnosperms and angiosperms
Reproductive differences in seedless vs. seed plants • Sporangia • Seed plants have 2 types: megasporangium, microsporangium • Protection of egg • Non- seed plants utilize an archegonium on the gametophyte to protect egg, sporophyte develops within archegonium • Seed plants protect entire gametophyte within ovule (which will develop into seed) • Transport of male gametophytes • Non-seed plants – use water for flagellated sperm • Seed plants – male gametophyte carried by wind (pollen) • Sporophyte vs. gametophyte • Non-seed – sporophyte dependent on gametophyte • Seed – gametophyte dependent on sporophyte
Plant Taxonomy, continued • Refer to previous PowerPoint for Seedless plant taxonomy • Domain Eukarya • Kingdom Plantae • Phylum Cycadophyta Cycads • Phylum Ginkgophyta Ginkgos • Phylum GnetophytaGnetophyta • Phylum Coniferophyta Conifers • Phylum Anthophyta Flowering Plants • Class EudicotsDicots • Class Monocots Monocots
Gymnosperms • “Naked Seed” • Ovules and seeds of gymnosperm are exposed on cone scale • Microsporangia and megasporangia located on different cones, sometimes different plants • Female cones are larger than male cones
GymnospermsCycads • Cone-bearing, palmlike plants found mainly in tropical and subtropical regions
GymnospermsGinkgos • Only 1 species survives today • Usually only male trees are used since female trees produce smelly seeds
GymnospermsGnetophytes • Can grow as shrubs, trees, or vines
GymnospermsConifers • Largest group of gymnosperms • Evergreens – pines, hemlocks, spruces • Nonevergreens – cypress tree
GymnospermsPine Cone • Female • Male – small “dots” are pollen
Angiosperms • Dominant plants today • “Flowering Plants” • Microsporangia and Megasporangia located on same flower • Double Fertilization • Mature pollen grain contains 2 sperm • 1 fertilizes egg • Other joins 2 polar nuclei to form endosperm (food for embryo)
AngiospermsFruits • Develops from ovary • Ovary wall thickens to be pericarp • 3 layers • Exocarp – skin of fruit • Mesocarp – fleshy part • Endocarp – boundary around seed • Review Dichotomous key on page 287
AngiospermsFruits • Simple Fruits (develop from single ovary) • Fleshy fruits • Drupes – cherry • Berries – grape, tomato • Pomes – apple • Dry fruits • Legumes – pea • Samaras – maple • Nuts – oak, walnut • Grains – wheat, corn • Achenes -- sunflower, dandelion • Aggregate Fruits (develop from numerous ovaries within a single flower) • Blackberries • Raspberries • Strawberries • Multiple fruits (develop from a number of ovaries of several flowers) • Pineapples • Mulberries • Figs