1. Plant Diversity I: How Plants Colonized Land

3. Four Key Traits Plants share with ancestor The four key traits that plants share with charophyceans (algae) are: Rose-shaped complexes for cellulose synthesis: rose shaped arrays of proteins in the plasma membrane that synthesize the cellulose microfibrils of the cell walls. Peroxisome enzymes: contain enzymes that help minimize the loss of organic products as a result of photorespiration. Structure of flagellated sperm: in certain species of land plants, the structure of the flagellated sperm resembles the one that is in the charophyceans. Formation of a phragmoplast: certain steps in cell division occur only in land plants and some charophyceans;

4. Adaptations Enabling the Move to Land Species of charophyceans: green algae live in shallow water in ponds and lakes (close to the edges) – thus more chance of dry times Charophyceans have adapted: a layer of sporopollenin around zygote (also seen around plant spores)

6. Morphological and Biochemical Evidence Key characteristics of land plants are also found in protists (mainly algae) Plants are: Multicellular Eukaryotic Photosynthetic autotrophs

7. Plants have….. Cell wall made of cellulose Apical meristem Alternation of generations Walled spores made in sporangia Multi-cell gametangia Cuticle (in some) Secondary compounds (in some) Alkaloides, tannins, flavonoids: bad flavor or smell

12. Bryophyte Phyla Liverworts Named for shape of plant and the suffix -wort, meaning herb. Hornworts Named for shape of plant and the suffix -wort, meaning herb. Mosses Most familiar bryophytes

15. Bryophyte Gametophytes Gametophytes are a more dominant generation and are most visible, such as moss. The flagellated sperm needs a covering of water in order to travel to the eggs

17. Bryophyte Sporophytes Green and photosynthetic when young Cannot live independently Always attached to parental gametophytes; sugars, amino acids, minerals and water are obtained from them Bryophytes have the smallest and simplest sporophytes Larger and more complex sporophytes came later down the line when vascular plants evolved

18. Sporophytes Contains Sporangium: produce spores by mieosis Can make up to 50 million spores in one capsule Spores are haploid Spores have little food stored Spores can survive for a long time in bad conditions

21. Origins and Traits of Vascular Plants 420 million years old Have branched sporophytes NOT dependent on gametophyte Multiple sporangia Made production of spores easier Increased survival

22. Vascular plants (1 st ferns) Life Cycles with Dominnant Sporophytes Transport in Xylem and Phloem Tracheids: tube cells in xylem Evolution of Roots Evolution of Leaves: Microphyls: needles, 1 vein Macrophyls: all other leaves w/ many veins Sporophylls: leaves on which spores grow.

25. Significance of Seedless Vascular Plants “Seedless vascular plants dominated the earliest forest. Their growth may have helped produce the major global cooling that characterized the end of the Carboniferous period. The decaying remnants of the first forests eventually became coal.” (p. 590)

26. Evolution of Plants Bryophytes Hornworts Liverworts Mosses Seedless vascular plants Ferns Vascular plants with seeds Flowering vascular plants with seeds

28. Works Cited Information from: AP Biology Book www.course-notes.org Images from: AP Biology Book www.google.com