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QUICKSTUDY ¨ Guide Is an Outline of the Basic Topics Taught in Botany Courses

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BarCharts, Inc.® WORLD’S #1 ACADEMIC OUTLINE • Study of the Plant Kingdom... Our Essential Partners in Life • INTRODUCTION ALTERNATION OF GENERATIONS What’s so special about plants? A unique evolutionary strategy for repro- • They are photosynthetic, using the ultimate energy duction where a single plant organism has Haploid source, the sun, to make their own food. For this reason two phases to its life history. Gametophyte they are called autotrophs. Plants power most (n) Antheridium ecosystems and are thus essential to life on Earth. • Gametophyte – Haploid, multicelled Spore Have you thanked a plant today? individual produces gametes via mitosis. Archegonium Dominant form in lower plants. Sperm n n Egg • Sporophyte – Diploid, multicelled individual n n Spores from gamete fusion (zygote); produce haploid Meiosis Syngamy GAMETE EVOLUTION spores via meiosis for dispersal; spores Plants have developed different strategies for gamete germinate via mitosis to produce gameto- 2n 2n Spore mother cell Zygote production and fusion. phytes. Dominant form in higher plants. Embryo • Isomorphic A/G – Gametophyte and sporo- 2n • Isogamy – Gametes are equally motile and of similar phyte individuals are morphologically indis- Sporangia size. tinguishable. Sporophyte • Anisogamy – One gamete • Heteromorphic A/G – Gametophyte and is large and less motile, Female(+) Male(-) (2n) sporophyte individuals are morphologically Diploid with nutrient reserves, distinct. while the other is smaller and more motile, with few nutrient reserves. Isogamy • Oogamy – One gamete is PLANT CLASSIFICATION NONVASCULAR PLANTS non-motile and large, with 1st Plants on Land large nutrient reserves SEEDS, VASCULAR • Lack vascular tissues (egg), while the other is Anisogamy • Gametophyte is dominant, sporophyte nutritionally smaller and motile Angiosperms dependent on gametophyte. (sperm) and must • Small; live in moist environments; gametes released locate the larger into water. gamete. Oogamy a. Division Hepatophyta (Liverworts) b. Division Anthocerophyta (Hornworts) Gymnosperms c. Division Bryophyta (Mosses) PLANT EVOLUTION (a) (b) Plant evolution: Land colonization occurred about 400 SEEDLESS, VASCULAR mya, likely from aquatic, green algae ancestor. Ferns • New problems on land: Plants must adapt to living Club Mosses in the air, a non-aquatic, dry medium. This presents some problems: Sporophyte - Obtaining water and preventing water loss. - Transporting water and nutrients. Horsetails Gametophyte - Gas exchange (requires moisture) Growing - Gravity region - Reproduction when gametes swimming in water is Foot of limited. Whisk Ferns sporophyte - Temperature flux of air is more rapid than in water. (c) Plant adaptations/solutions NONVASCULAR Capsule • Chlorophyll A & B, to capture sunlight – similar to Sporophyte green algae chlorophyll. • Starch storage, for prolonged inactive periods during Mosses Seta seasonal variations. • Gametes protected and kept moist inside plant Foot tissues. • Stomata (leaf openings) to regulate gas exchange. Gametophyte • Wax surfaces to prevent excess water loss. Liverworts • Root system to pull in water and nutrients from soil. • Conduction tissues to transport water, nutrients and food. Hornworts • Support tissues to battle gravity for vertical growth. • All of these adaptations have greatly enhanced the success of plants on land today. GREEN ALGAL ANCESTOR 1 SEEDLESS VASCULAR PLANTS SEED “Ferns” Seedless Vascular plants Microphyll Evolution Extinct fossil forms that • Possess xylem & phloem for transport of materials. • Sporophyte is dominant. Stem may show transition from Microphyll seedless vascular plants • Evolution of leaf for efficient light capture. Vascular - Microphylls, megaphylls (In botany, the prefixes tissue (e.g., ferns) to vascular "micro" and "mega" generally refer to similar seed plants (e.g., structures in male and female parts of the plant, Unbranched Vascular Leaf with gymnosperms and respectively). stem Projection supply to one vein angiosperms). • Division Lycophyta (Club Mosses) projection - Roots present. Megaphyll Evolution - Leaves present (microphylls). • Division Psilophyta (Whisk Ferns) No roots or leaves Main axis of stem • Division Sphenophyta ( Horsetails) FLOWERS - Roots present. Overtopping • Most plants are angiosperms and thus produce - Stems contain silica. (one branch becomes Dichotomously flowers with both male and female reproductive - Leaves present (microphylls). branching stems Side main axis of stem) - Division Pterophyta (Ferns) branch structures. - Roots present. Megaphylls • Flower anatomy - Leaves (= fronds) - Sepals, petals - Fronds present (megaphylls). - Stamen (Male Portion): Anther, filament - Fern life history (see fig. below) - Pistil (Carpel, Female Portion): Stigma, style, - Sporophyte, sori, sporangia, spores, gametophyte ovary, ovule (= prothallus), archegonium with eggs and antheridium with sperm Leaves with The pistil Stigma Petal { many veins Anthers • The Plant Scene (300 mya): Many seedless vascular contains Style The stamen Webbing of side (micro- contains plants and some nonvascular plants exhibited lush, branch systems the female Ovary organs {Ovule sporangia) the male dense growth covering large expanses in Earth’s history. organs • Much of today’s oil, coal and gas deposits were formed by these plants. OVULE TO SEED Evolution of the "seed" plants • Terrestrial adaptations of seed plants. Megasporangium (2n) Seed coat (2n) (derived from integument) - Gametophytes protected in moist sporophytic, Integument (2n) Female reproductive tissues. gametophyte (n) Food Spore case (n) supply - Pollination replaced swimming for sperm delivery to egg. Egg Filament Pollen (derived nucleus - The seed evolved - a dormant embryo with tube (n) from surrounding nutrients protected from environ- (n) female Sepal mental conditions. Seeds replaced spores as gameto- phyte dispersal agents, using wind, water or animals. Micropyle tissue) • The seed - a fertilized egg Receptacle - Inside an ovule. Discharged sperm nucleus (n) - Integument, megasporangium ➔ megaspore Megaspore (n) Embryo (2n) (new sporophyte) ‘gametophyte ➔ egg sperm (a) Ovule (b) Fertilized ovule (c) Seed FERN LIFE HISTORY The sporophyte • Angiosperms have dominated the plant scene since the (still attached to demise of dinosaurs and many gymnosperms the gametophyte) (Cenozoic era, 65 mya to present). grows, develops • Seed in a protective container or cotyledon • Angiosperm life cycle: - Microspore mother cell ➔ microspores ➔ pollen grain (male gametophyte)which includes tube cell and generative cell (sperm) - Megaspore mother cell ➔ megaspore ➔ embryo zygote rhizome Diploid Stage sorus sac with 7 cells and 8 nuclei (female gametophyte) fertilization meiosis ➔ egg Haploid Stage Archegonium Sporangia - Two sperm move through the pollen tube and Spores develop The spores are engage in a double fertilization (where one sperm egg released from a producing Prothallus fuses with the egg to form a zygote/embryo, and the egg spore chamber structure mature other sperm fuses with a large, central cell to form gametophyte sperm (underside) A spore endosperm/nutrient reserve for the embryo) until it producing germinates and can produce its first leaves and begin photosyn- sperm structure grows into a gametophyte thesis. Antheridium - Pollination and fertilization occur within hours to days, making angiosperms quick reproducers, compared to gymnosperms. TRENDS IN ALTERNATION OF GENERATIONS • Flowers ensure pollination by insects, birds and mammals. Gametophyte (n) Sporophyte (2n) - Flowers and pollinators co-evolved. Gametophyte (n) • Seed dispersal Sporophyte (2n) - Important because plants may drop seeds close by, Sporophyte (2n) but new individuals will possibly compete with parent plants. - Wind, water and animals are common dispersal agents. - Fruits can entice animals to aid in dispersal. • Fruits – ripened ovary (see fig.) • Monocots and Dicots - two major groups of Gametophyte (n) • Sporophyte dependent on gametophyte (e.g., bryophytes) angiosperms (see fig. for differences) - Monocots include grasses, corn, sugar cane, palm • Large sporophyte and small, independent gametophyte (e.g., ferns) trees, lilies and orchids. • Reduced gametophyte dependent on sporophyte (seed plants) - Dicots include most trees, vines, shrubs and cacti. 2 THE GYMNOSPERMS - “naked seed” plants • Dominant plant when dinosuars ruled (Mesozoic era, 220 - 65 mya). GYMNOSPERM LIFE CYCLE • Do not produce flowers. • Ovules/seeds exposed. Megaspore(n) • Division Cycadophyta Scale of - Slow-growing palm-like trees found female cone primarily in tropics and sub-tropics. Female cone HAPLOID • Division Ginkgophyta Gametophyte - Only one living member. generation - Ginkgo biloba (common diet Megasporangium Pollen chamber supplement) Micropyle • Division Gnetophyta Ovule Male cones Note that the same plant has both Female - Closest living relatives of angiosperms pollen-producing male cones and MEIOSIS gametophyte(n) - Ephedra egg-producing female cones Egg - Drug ephedrine originally derived from this Microspore Microspores(n) plant. mother cells(2n) Reduced Germinating pollen - Cells resemble xylem vessel cells of arche- produces pollen tubes to reach the egg. angiosperms. gonium Male gametophyte - Cone clusters resemble flowers. Pollen (germinating pollen • Division Coniferophyta (Conifers, grain grain) Evergreens) FERTILIZATION The gametophytes - Oldest, tallest, most massive plants (e.g., Sporophyte(2n) Scale of are tiny male cone DIPLOID 380 ft. tall Redwood
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  • Development and Cell Cycle Activity of the Root Apical Meristem in the Fern Ceratopteris Richardii

    Development and Cell Cycle Activity of the Root Apical Meristem in the Fern Ceratopteris Richardii

    G C A T T A C G G C A T genes Article Development and Cell Cycle Activity of the Root Apical Meristem in the Fern Ceratopteris richardii Alejandro Aragón-Raygoza 1,2 , Alejandra Vasco 3, Ikram Blilou 4, Luis Herrera-Estrella 2,5 and Alfredo Cruz-Ramírez 1,* 1 Molecular and Developmental Complexity Group at Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico; [email protected] 2 Metabolic Engineering Group, Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Sede Irapuato, Km. 9.6 Libramiento Norte Carretera, Irapuato-León, Irapuato 36821, Guanajuato, Mexico; [email protected] 3 Botanical Research Institute of Texas (BRIT), Fort Worth, TX 76107-3400, USA; [email protected] 4 Laboratory of Plant Cell and Developmental Biology, Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia; [email protected] 5 Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA * Correspondence: [email protected] Received: 27 October 2020; Accepted: 26 November 2020; Published: 4 December 2020 Abstract: Ferns are a representative clade in plant evolution although underestimated in the genomic era. Ceratopteris richardii is an emergent model for developmental processes in ferns, yet a complete scheme of the different growth stages is necessary. Here, we present a developmental analysis, at the tissue and cellular levels, of the first shoot-borne root of Ceratopteris.