Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bryophytes Pteridophytes Adaptations of Land Plants Bio 1B Fall 05 Land Plants Professor Thomas Carlson 1 2 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Land Plants Green Algae Charophyta Figs 29 4 29 7 progenitor to Green Land Plants 460 million years ago land plants evolved from aquatic green algae the green algae were probably from fresh water Green Land Plants cellulose cell wall chlorophyll a and b starch storage product in chloroplast embryo protected by tissue of parent plant alternation of generations 400 million years ago first vascular tissue stomata roots 380 million years ago 360 million years ago 260 million years ago 125 million years ago first wood first seeds first vessels in vascular system first flowers 3 4 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Adaptations to Life on Land Adaptations to Life on Land Fig 29 5 Apical Meristems of Shoots Roots Fig 29 5 Thick spore walls that prevent desiccation resist decay Cuticle waxy covering that retards desiccation drying Gametangia enclose plant gametes prevent them from drying Archegonia encloses eggs Antheridia encloses sperms Stomata developed for gas exchange Pigments that protect plant against UV radiation Land Plants Optimize Photosynthesis CO2 from atmosphere is more available on land LIGHT from sun is more available on land Embryos young sporophytes contained within protective structure 5 6 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Adaptations to Life on Land Bryophytes Non tracheophyte plants Vascular Tissue Earliest land plants Most are only a few cm high or long Grow in dense mats in moist habitats Alternation of generations Dominant haploid gametophyte Sporophytes are dependent attached to gametophyte Table 29 1 Figs 29 7 29 8 29 9 29 10 Vascular tissue enables transport of water against gravity from tissues in contact with wet soil to tissues in contact with air Hydroids tiny channel through which water travels in mosses Tracheids specialized conducting cells in pteridophytes gymnosperms Vessels specialized conducting cells in angiosperms Lignin strengthens cell walls of vascular conducting xylem and provides rigid structural support so plant does not fall over in response to gravity or wind 7 8 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bryophytes Non tracheophyte plants Bryophytes Non tracheophyte plants Sphagnum moss common name is peat moss Very abundant widespread in wetland bogs in northern latitudes Liverworts Marchantia Fig 29 9 Peat partially decomposed plant material resulting from rapidly growing upper layers of Sphagnum that compress deeper lying layers Fig 29 10 flat thallus with dichotomous branching Hornworts Fig 29 9 stomata development Sphagnum moss contains acidic compounds that are antiseptic is used to treat Mosses Polytrichum Funaria Fig 29 9 apical cell division hydroids primitive vascular tissue green leaf bearing structure is the gametophyte diaper rashes athelete s foot to dress wounds 9 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu 10 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Tracheophytes Bryophytes mosses non tracheophytes Pteridophytes ferns seedless tracheophytes Figs 29 12 29 14 Contain tracheids which are the principal water conducting element of the xylem water mineral transport rigid structural support Sporophytes are much larger than gametophytes Dominant and independent sporophyte phase Both sporophytes and gametophytes produce their own food through photosynthesis Non seed tracheophytes pteridophytes sporophyte is small and depends on the gametophyte for nutrition Seed containing tracheophytes gymnosperms angiosperms 11 12 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Seedless Tracheophytes Pteridophytes Seedless Tracheophytes Pteridophytes Table 29 1 Figs 29 7 29 12 29 14 Haploid diploid generations independent at maturity Rhyniopsida only known from fossils Lycopods Lycophyta simple leaves in spiral Horsetails Anthrophyta simple leaves in whorl Equisetum is genus name Sporophyte dominant independent Reproduce by single celled spores rich deposits of silicon in cell walls used to scour pans tea used as a diuretic Small gametophytes 1 2 cm long short lived Require aqueous environment for motile flagellated sperm to fertilize Whiskferns Psilotophyta Ferns Pterophyta 13 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Ferns Pterophyta 14 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Frond fern leaf Fig 29 12 Figs 29 12 29 14 large complex leaves branching vascular strands roots leaves stems Developing frond crozier or fiddlehead fiddleheads of some species consumed as delicacy require water for transfer of male gametes to female gametes Sporophyll frond that produces spores sori clusters of sporangia under leaf surfaces moist terrestrial environments most ferns Sporangia spore producing structures that are often aggregated under the leaf into patches called sori some ferns are aquatic epiphytic or live on rocky cliffs Haploid spores develop into gametophytes 15 16 Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Bio 1B Fall 05 Lecture Land Plant Adaptations Professor Thomas Carlson tcarlson berkeley edu Seedless Tracheophytes Pteridophytes Azolla aquatic fern Homosporous terrestrial pteridophytes Floating water fern with a symbiotic relationship with cyanobacteria which live in leaf cavities Heterosporous aquatic ferns e g Azolla Marsilea Cyanobacteria Homospory
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