Chapters 29 and 30

Characteristics of All Plants Multicellular Eukaryotic Photosynthetic autotrophs Alternation of generations

Evolutionary History Evolved from green algae Charophyceans are closest living relatives Homologous structures provide evidence: Chloroplasts Walls with cellulose Peroxisome enzymes Flagellated sperm

Adaptations for Land Preventing water loss Sporopollenin Walled spores produced in sporangia Cuticle Stomata

Adaptations for Land Obtaining light,CO2, and nutrients Apical meristems Mycorrhizae Roots & root hairs Vascular tissue Phloem Xylem Lignin

Adaptations for Land Defense against herbivores and microbes Chemical compounds

Four Main Groups of Land Plants Bryophytes Pteridophytes Gymnosperms Angiosperms

Bryophyta Simplest land plants- None have roots, stems, or leaves Mainly nonvascular

Bryophyta All have dominant gametophyte generation.

Bryophyta Liverworts: No stomata Hornworts: Stomata Mosses: Have stomata, and very simple vascular tissue.

Bryophyta Economically important Sphagnum moss, peat moss Water retention Oil spill control Fuel

Seedless Vascular Plants Pteridophyta (ferns & horsetails) are main group Also includes Lycophyta (club mosses)

Seedless Vascular Plants Sporophyte generation dominant

Seedless Vascular Plants Evolution of vascular tissue: Xylem Tracheids – dead, lignified Phloem Allowed increased height

Seedless Vascular Plants Evolution of leaves

Seedless Vascular Plants Evolution of roots Rhizomes

Seedless Vascular Plants Evolution of sporophylls Sori Strobili

Seedless Vascular Plants Formed first forests Eventually formed coal burned today

Gametophyte Evolution Further reduced in seed plants. Protected in ovules and pollen grains.

Evolution of Heterospory Megasporangia Microsporangia

Evolution of Pollen Avoided need for water Allowed greater dispersal

Gymnosperms “Naked” seeds Include cycads, ginkgos, gnetophytes, and conifers.

Angiosperms “Container Seed” Flowers Fruits 90% of all plants

Angiosperms

Coevolution: Pollinators & Flowers

Angiosperms Four Main Groups: Basal Angiosperms (.04%) Magnoliids (3%) Monocots (28%) Eudicots (69%)

Monocots vs. Dicots Cotyledons

Monocots vs. Dicots Leaf Venation:

Monocots vs. Dicots Vascular Tissue in Stems

Monocots vs. Dicots Roots

Monocots vs. Dicots Flowers

Angiosperms Importance: Food Lumber & Paper Medicine Oxygen