18_FungiW11 - Green Plants & Fungi • Seed Plants...

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Unformatted text preview: Green Plants & Fungi • Seed Plants – Gymnosperms – Angiosperms • Flowers • Slime Molds • Fungi – Ecology – Mycorrhizae – Life cycle & major groups Happy Valentine’s Day Seed Plant Reproduction: Gymnosperms male, even in sporophyte meiosis mitosis pollen =male gametophyte Microspore Cones with microsporangia PO LL INA TIO N Megasporangium IS MEIOS megaspore pollen Ovulate cone Ovules Mother cell 2n n Embryo Sporophyte sporophyte Seed Eggs gametophyten archeogonia pollen produce sperms; make pollen tube Figure 30-19 Seed plants have vascular tissue and make seeds. Cycadophyta (cycads) Ginkgophyta (ginkgo) Other conifers (redwoods, junipers, yews) Gnetophyta (gnetophytes) Pinophyta (pines, spruces, firs) Anthophyta (angiosperms or flowering plants) Seed Plants: Gymnosperms • “Naked Seeds” – seeds not enclosed before pollination like angiosperms seeds are • No flowers Gymnosperms: Gingkophyta • Ginkgos • One living species: Ginkgo biloba • Deciduous – Loses leaves in fall • Separate sexes Gymnosperms: Conifers • Pinophyta or Coniferophyta – Book uses Pinophyta & excludes some groups • Most use cones for reproduction • Pines, firs, junipers • Non-deciduous • Major forest forming species • “Soft Wood” male cones smaller typically Reproduction on Land: Angiosperms and Flowers • Male microsporangium develop in anther – microsporangium develop in anther • Female – Megasporangium develop in ovary • Flowers may contain one or both sexes stigma anther carpel style filament stamen ♀ ovary ♂ Reproduction on Land: Flowers & Fertilization • Pollen lands on “stigma” at the top of the “style” • Tube forms allowing pollen access to ovary • Two sperm ejected into ovary Reproduction on Land: Flowers & Fertilization Double fertilization • One fuses with egg to form zygote (2N) • One fuses with two polar nuclei to form endosperm (3N) – Endosperm provides nutrition to embryo Reproduction on Land: Angiosperms Angiosperms are the Flowering Plants pollen anther flower of sporophyte Microspore PO LL INA TIO N Ovule Ovary Carpel Egg Megasporangium Nutritive tissue Embryo devloping sporophyte Megaspore n gametophyte endosperm 3n double fertilization zygote 2n seed Flowers & Pollination • Wide diversity of flowers & pollinators • Pollinators – Disperse pollen – Specialized pollinators ensure pollen gets to same species – Rewarded with nectar and pollen Flowers & Pollination • Bat pollinators –strong smelling Large, white, night blooming flowers – Strong smelling large , white, night bllooming • • Bird pollinated –red bell orbell shaped Red, tube or tube shaped Bee pollinated – brightly colored and scented scented Brightly colored & – Structured so bee can land structures so been can lanxd Plant Mutualisms Pollination (Angiosperms) mitochondria chloroplasts Mitochondria (Eukaryotes) mycorrhizae seed dispersal Seed Dispersal (Seed Plants) Chloroplasts pollination (Plantae) Mycorrhizae (Land Plants) Archaea AMOEBOZOA UNIKONTA Unikonts • Single Flagella – May not be true synapomorphy OPISTHOKONTA Fungi Choanoflagellates Animals PLANTAE • Triple gene fusion Red algae Green algae Land plants RHIZARIA Foraminifera CHROMALVEOLATA ALVEOLATA Dinoflagellates STRAMENOPILA Diatoms Brown algae Unikonts: Amoebozoans Lobe shaped pseudopodia Unikonts: Single flagella Engulf food Ameobozoans Fungi Choanoflagellates Opisthokonts: Flagella at rear of cell Animals Amoebozoans: Slime Molds • Slime Molds • Form “Supercells” – Large multinucleate cells • Reproduction – Form fruiting bodies that undergo meiosis & form wind-borne spores – Spores germinate into haploid amoeba – Haploid amoeba fuse Fungi • Eukaryotes • Opisthokonts (flagella at rear of cell) • Absorb nutrients directly from the environment Fungal Morphology • Must maintain high SA/V Single cells: “yeasts” Mycelium (-ia)- multicellular Filaments or “hyphae”: 1 cell wide Fungal Ecology: Decomposers • “saprophytes” digest dead material • Break down lignin & cellulose – Use cellulose for energy – Only break down lignin to get to cellulose Laetiporus gilbertsonii Sulfur Shelf fungus “Tree Brain” fungus Thesneeze.com Fungal Ecology: Parasites • Not major cause of disease in humans • Common disease in plants – Also called smuts, rusts, mildew • Chestnut Blight – Introduced to No. America in 1900 – By 1940 American Chestnut Trees almost extinct Fungal Ecology: Mutualism • Mycorrhizae – Absorb nutrients in soil – Transfer them to plants – Increase root SA/V – Enzymes efficient at breaking down molecules to release nutrients Hygrocybe psittacina Green Parrot Toadstool Fungal Mutualism: Experiment Hypothesis (H1): Host plants provide mycorrhizal fungi with sugars, fungi provide plants with phosphorous or nitrogen from soil Null Hypothesis (H0): No exchange of sugars or nutrients Prediction H1: Labeled C transferred to Prediction H1: Labeled P or N transferred mycorrhizae in treatment. In control, little to plant in treatment. In control, little or labeled carbon found in soil no labeled N or P in plant Prediction H0: No difference in carbon localization Prediction H0: No difference in P or N localization Figure 31-9 Mycorrhizal Types • Ectomycorrhizae (EMF) – – – – Cover root tips Do not penetrate cells Temperate latitudes Mostly in Basidiomycota clade EMF Cross section of plant root Mycorrhizal Types • Arbuscular Mycorrhizae (AMF) – Grow into root cells – 80% of all plant species – Key in land transition AMF Cross section of plant root Fungi: Taxa • Chytrids • Basiodiomycota (club fungi) • Ascomycota (lichen formers) Chytrid Fungi • Primarily aquatic • Mutualists in guts of mammal herbivores – Digest cellulose • Factor in global amphibian declines Chytrid Life Cycle Only fungi in with alternation of generations. (a) Chytrids include the only fungi in which alternation of generations occurs. SIS I TO M MI TOSIS Zygote Gametes (n) Sporophytic mycelium Spores form in sporangia 1 mm Spore 2n Haploid (n) Diploid (2n) Fungal Reproduction & Life Cycle • Mycelium is haploid • Plasmogamy – – – – Cells of hyphae Nuclei do not fuse N+N cell (Not 2N) “heterokaryotic” • Karyogamy – Fusion of nuclei Amanita muscaria Basidiomycota (club fungi) • Includes fungi that produce mushrooms – Mushrooms produce spores • Basidia= cells where spores form • Saprophytes – Only fungi that can digest lignin • Ectomycorrhizae (EMF) Basidiomycota Life Cycle 2n Basidium Spores Spores form hyphae PLASMOGAMY IS TOS MI Hyphae of different mating types Haploid (n) Heterokaryotic (n + n) Diploid (2n) Figure 31-13d Ascomycota Soredia Asci produced by fungus • Ascus: cup-like reproductive structure • Includes – lichens:Symbiosis with cyanobacteria or green algae – Saprophytes – EMF – parasites (Cordyceps) • Human uses – Penicillin – Truffles – Wine & cheese Fungal layer Algal layer Fungal layer rock 1 cm Ascomycota: Life Cycle Spores form hyphae Spores Ascus 2n Dikaryotic mycelium Hyphae of different mating types make contact and fuse Haploid (n) Heterokaryotic (n + n) Diploid (2n) Figure 31-12 ...
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