Presentation on theme: "Invasion of land Stomata: opening: allows CO2 into the leaf Cuticle: Protects from water loss Vascular tissue: xylem and phloem Roots: absorb nutrients."— Presentation transcript:
Invasion of land Stomata: opening: allows CO2 into the leaf Cuticle: Protects from water loss Vascular tissue: xylem and phloem Roots: absorb nutrients and water vs. rhizoids of moss and holdfasts of algae that don’t. Seeds: dormancy Fruit: seed dispersal Flowers: pollination/reproduction
Cuticle –A waxy cuticle covers parts exposed to air to prevent dessication. Openings in the cuticle (stomata) allow for gas exchange and are controlled by the guard cells. Guard cells
Vascular tissue –xylem (water and minerals) and phloem (nutrients). –Picture shows vascular tissue in a leaf in a bundle known as a vein. These are the lines you can see in the leaf.
Carbon dioxide Plants lowered the levels of carbon dioxide from 25X current levels to current levels over a period of 100 million years as they adapted to and spread on land.
Cuticle, Dermal tissue, ground tissue, and vascular tissue
Flagellated sperm vs. pollen The more primitive plants have flagellated sperm that allow them to swim to the egg. This means that the mosses, ferns, and other primitive plants require water to have fertilization. Fern sperm Types of pollen
Plants NOTE: We use the term Divisions instead of the term Phyla when referring to plants. Characteristics of plant kingdom members –Alternation of generations with the diploid sporophyte generation dominant except in bryophytes
Plant Divisions: Bryophyta MOSSES Dominant gametophtye generation (green) Also includes liverworts and hornworts Need sperm to fertilize egg NO vascular tissue limits height of the plant and therefore have no true roots, stems, or leaves. haploid spores are made by meiosis in the sporangium of the sporophyte. Moss sporophyte
Pterophyta: Ferns Homosporous: create one spore that is bisexual. Vascular tissue but no seeds: allows them to get taller, but limits them to shady moist areas for reproduction. Fronds: big “leaf like” arrangement Fiddlehead: emerging sporophyte Sporangium make spores on underside of fronds when reproducing.
Ferns Fiddlehead Sporangia on underside of frond Fronds Bisexual gametophyte
Gymnosperms (naked seeds) have no flowers: gingko, cycad, and conifers
Coniferophyta Redwoods, firs, pines, yews, cypresses Naked seeds: not enclosed in fruits Wind pollination (NEEDS A LOT) Seeds, vascular tissue No flowers Often needles thick with cuticle and small in size to limit transpiration.
Oldest and largest Redwoods (400 feet tall) bristlecone pine (4600 years old)
Anthophyta Flowering plants Flower will develop into fruit that is used for seed dispersal via wind, water, or animal. Pollination can be by wind, bird, bat, insect. Most advanced (recent) Gametophyte is reduced and within the flower. Most diverse: grasses to trees
Monocot and Dicot The subdivisions of angiosperms. One cotyledon or two cotyledons
#2: veination in the leaves Parallel veinsNetlike veins MonocotDicot
Flower structure: reproduction organ of some plants
Flower parts Pistil/Carpel: synonym for female part –Ovary-makes the eggs within the ovule –Style-extends from the ovary away from plant –Stigma-on the end of the style it collect pollen with its stickiness Stamen: male part of flower –Anther makes pollen –Filament – holds anther away from plant Sepals: protect flower before blooming Petals: attract pollinators
Parts: functions Female (carpel/pistil) –Stigma is sticky “top” that collects pollen –Style is connection between stigma and ovary. –Ovary is where eggs are made in the ovules Male (stamen) –Anther makes the pollen –Filament holds anther away from female part to allow for wind/insect to carry pollen away Petals (collectively called corona): attracts pollinators Sepals (collectively called calyx); protects the bud before blooming
Double Fertilization Generative nucleus becomes two “sperm” through mitosis. First sperm fertilizes egg in the ovule and second sperm fertilizes polar nuclei to become triploid endosperm. Endosperm will become “food” for seed.
Seed and Fruit Seed: covering (seed coat), food (endosperm) and embryo. Dormancy vs. Germination The ripened ovary becomes the fruit after the fertilization of the egg and formation of the seed. (Contains the seed) Purpose: Seed dispersal
Review What division of plants has no vascular tissue? What is made by the archegonium? What part of the flower “catches the pollen? What is one gymnosperm other than coniferophyta? What part of a flower becomes the fruit? Where do you find the sporangium on a fern?
More review What process makes the gametes in a plant? What division of plants includes the tallest trees? What is the purpose of the fruit? What is the food of a seed called? What group of green algae are the closest relatives to plants? What does the cuticle prevent? How many flowers lead to an aggregate fruit? What is true of plants that are heterosporous?