Eukarya- > byo, heterotrophic eukaryote acquired cyanobacteria symbiont- Photosynthetic descendantso The clade Archaeplastida containing red algae, green algae, and plants- Embryophytes: land plantso Closest relative: chorophytes- Charophytes and Chlorophytes: green algaeEvidence for charophytes and plants (embryophytes)- Shared derived characterso Genertic evidence: nuclear and chloroplast genomeso Morphological and iochemical traits Specific kind of cellulose synthesis structure for cell wall synthesis Some unique enzymes- 3 charophyte species (freshwater, aquatic) closest living relatives of plantso Chara specieso Coleochaete species o SpirogyraHow are plants (embryophytes) different from charophytes?- *Alternation of generations for reproduction, how defined?o Where are things haploid and diploid?o Where do mitosis and meiosis occur?- *Apical meristems (primary or ”reaching” growth); don’t have this as humanso Share by all plant groups- Protection of gametes within multicellular archegonia and antheridia- Walled spores in sporangiaTimeline- 475 mya: fossil evidence of first land plants- 420 mya first vascular plants- 370 mya first forests- 305 origin of extant seed plants- 130 angiosperms (flowering plants)- 0.013 mya (13,000) cultivation of plants- How can there have been forests if no seed plants yet?o Lichophytes (tree-like): source of coal bedso They were seedless but had vascular flieso Higher oxygen concentration so size of insects could be largero Have to be vascular plantso Tree ferns came a little laterChallenges of transition from water to land- Charaphyte (green algae): holdfast, stipe (looks like stem), blade (looks like leaf)- Angiosperm: roots, stems, leaves (true b/c have vasculature)- Most similarities in morphology for chara and plants are homoplasies (analogies) - Plants in water don’t need as much structure b/c they are in water and held up by the water density- Flowering plant: in air which is a lot less dense than water; need different features to stand up- Structure in both is spreading out photosynthetic tissue in order to capture more sunlight- One big cell would not work, due to supply and demand, but many little cells thinly spread out would work- Turgor: as living plant cells take up water they have pressure inside against cell walls that providesupportProtista PlantaeBryophytesMosses, liverwortsPtreophytesWhiskferns, horsetails, fernsGymnosperms AngiospermsNonvascular plants (bryophytes  mosses)Seedless vascular plants (pterohytes, lychophytes)Gymnosperms ( conifers, cycads, Ginko, etc.)Angiosperms (flowering plants)Overall Plant Form and Function- Form must accommoadate basic needso Metabolismo Supporto Transporto Storage (products of metabolism)o Reproduction- Organization of body- Two types of growth o vegetative  primary secondary o reproductive)Plant organs- Leaves: photosynthesis- Stems: nutrient transport and support- Roots: nutrient uptakePlant tissues- Dermal tissue: coats surface of organ; protective layer- Ground tissue: photosynthesis- Vascular tissue: transportCell types- Parenchyma formo Cell membrane: selective barrier; semipermeableo Primary cell well: cellulose, thin and flexible, water and gas permeableo Most common cell typeo Function: metabolic activity and storageo Alive at maturity and retain ability to divide- Collenchymao Cell membraneo Primary cell wall: cellulose, unevenly thickened in some places (structure)o Function: provide flexible support but still allows growtho Elongating with stems and leaves they supporto Ex: strings of cellery- Schlerenchymao Cell membraneo Primary cell wallo Secondary cell well: btwn cell membrane and primary cell wall, thickened and lignifiedo Lignin restricts water transporto Function: usually strengthened by lignin and rigid (can’t elongate)o Often dead at maturityo Specialized: mechanical (sclerids and fibers); conductin (xylem tracheids & vessel elements)Vascular tissue for water and mineral nutrient transport: xylem- Tracheids & vessels dead at maturaity, lignified schlerenchyma essential for function- Tracheids, found in all vascular plants- Vessels, found in most flowering plants and a few othersWater delivery to all organs but 90-95% lost through transpiration (evaporation) on top of leavesTracheids- Thin, mm in length, tapered ends, water move from cell to cell thru pits- Veins?Vessel elements- Wider and shorter elements, but make up much konger (sometimes m in length) open “pipes”- Arteries?Vascular tissue for sugar solution transport: phloem- Sieve cells and sieve tubes accompanied by companion cells, live at maturity, parenchyma- Leaves: sugar production through photosynthesis- Roots: breaking down starch for sugars- Sieve cells: found in non flowering vascular plants- Sieve tube members: almost all flowering plantsXylem is dead & phloem is alive. Why?Xylem transports water and nutrients, phloem doesn’tXylem cells need to bed dead for diffusion to dominate at long distance