Eukarya byo heterotrophic eukaryote acquired cyanobacteria symbiont Photosynthetic descendants o The clade Archaeplastida containing red algae green algae and plants Embryophytes land plants o Closest relative chorophytes Charophytes and Chlorophytes green algae Evidence for charophytes and plants embryophytes Shared derived characters o Genertic evidence nuclear and chloroplast genomes o 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 plants o Chara species o Coleochaete species o Spirogyra How 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 humans o Share by all plant groups Protection of gametes within multicellular archegonia and antheridia Walled spores in sporangia Timeline 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 beds o They were seedless but had vascular flies o Higher oxygen concentration so size of insects could be larger o Have to be vascular plants o Tree ferns came a little later Challenges 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 provide support Protista Plantae Bryophytes Mosses liverworts Ptreophytes Whiskferns horsetails ferns Nonvascular 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 needs o Metabolism o Support o Transport o Storage products of metabolism o Reproduction Organization of body Two types of growth o vegetative primary secondary o reproductive Plant organs Leaves photosynthesis Gymnosperms Angiosperms Stems nutrient transport and support Roots nutrient uptake Plant tissues Dermal tissue coats surface of organ protective layer Ground tissue photosynthesis Vascular tissue transport Cell types Parenchyma form o Cell membrane selective barrier semipermeable o Primary cell well cellulose thin and flexible water and gas permeable o Most common cell type o Function metabolic activity and storage o Alive at maturity and retain ability to divide Collenchyma o Cell membrane o Primary cell wall cellulose unevenly thickened in some places structure o Function provide flexible support but still allows growth o Elongating with stems and leaves they support o Ex strings of cellery Schlerenchyma o Cell membrane o Primary cell wall o Secondary cell well btwn cell membrane and primary cell wall thickened and lignified o Lignin restricts water transport o Function usually strengthened by lignin and rigid can t elongate o Often dead at maturity o 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 others Water delivery to all organs but 90 95 lost through transpiration evaporation on top of leaves Tracheids 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 plants Xylem is dead phloem is alive Why Xylem transports water and nutrients phloem doesn t Xylem cells need to bed dead for diffusion to dominate at long distance w