Plant Evolution and Classification Natural Selection

Adapting To Land First plants had no roots Aquatic plants took nutrients from surrounding water Land plants had symbiotic relationship with fungi

Adapting To Land Preventing Water Loss Cuticle (waxy covering, decreases CO2) Stomata (Gas exchange, transpiration)

Adapting To Land Reproducing by Spores and Seeds Spore haploid cell with protective covering Seed is embryo with protective covering Some have endosperm that act as nutrients for embryo Absorbing and Transporting Materials Vascular tissue, support plants Xylem, transports H2O and inorganic nutrients , one way Phloem, transports carbohydrates and inorganic nutrients, wherever needed

Classifying Plants Plants evolved from algal ancestors Evidence of this relationship common photosynthetic pigments Store energy as starch Cell walls made of cellulose Nonvascular Does not have vascular tissue or true roots, stems, or leaves Vascular Has vascular tissue, true roots, stems, and leaves seedless (spore) or seed

Type of Plant Phylum Common Name Non Vascular Bryophyta Hepatophyta Anthocerophyta Mosses Liverworts Hornworts Vascular, seedless Psilophyta Lycophyta Sphenophyta Pteridophyta Whisk ferns Club mosses Horsetails Ferns Vascular, seed Gymnosperms Angiosperms Cycadophyta Ginkgophyta Coniferophyta Gnetophyta Anthophyta class Monocotyledones class Dicotyledones Cycads Ginkgo Conifer Gnetophytes Flowering plants Monocots Dicots

Alternating Life Cycles All plants have 2 phase life cycle called…. Alternation of generations Sporophyte (diploid, 2n) First phase produces spores Gametophyte (haploid cells, 1n) Second phase produces eggs or sperm

Nonvascular and Vascular Life Cycle Gametophyte is the dominant phase Sporophyte is larger and separate structure from gametophyte Gametes(spores) exchanged in “water” Sporophyte larger and dominant cycle Gametophyte seen as parasitic since it lives on the sporophyte and is nonphotosynthetic Reproduction; spore or seeds

Non Vascular Plant

Seedless Vascular Plants

Vascular Seed Plants