670 likes | 684 Views
This presentation provides an overview of fungi, including their characteristics, methods of obtaining nutrients, structure, and modes of reproduction. It also explores the classification of fungi and the importance of mycorrhizae and lichens in the environment.
E N D
How to Use This Presentation • To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” • To advance through the presentation, click the right-arrow key or the space bar. • From the resources slide, click on any resource to see a presentation for that resource. • From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. • You may exit the slide show at any time by pressing the Esc key.
Resources Chapter Presentation Visual Concepts Transparencies Standardized Test Prep
Fungi Chapter 26 Table of Contents Section 1 Overview of Fungi Section 2 Classification of Fungi Section 3 Fungi and Humans
Section 1 Overview of Fungi Chapter 26 Objectives • Listthe characteristics of fungi. • Describehow fungi obtain nutrients. • Distinguishbetween hyphae and a mycelium. • Comparethe ways fungi reproduce. • Describeone hypothesis about the origin of fungi.
Section 1 Overview of Fungi Chapter 26 Characteristics • Fungi are eukaryotic, non-photosynthetic organisms • can be unicellular or multicellular • Most are multicellular heterotrophs • Molds: tangled masses of filaments from cells • Yeasts: unicellular fungi whose colonies resemble bacteria • Mycology: the study of fungi
Section 1 Overview of Fungi Chapter 26 Characteristics, continued Obtaining Nutrients • Fungi are among the most important decomposers of organic matter. (saprophytes-important recyclers) • Fungi obtain nutrients by secreting enzymes and absorbing simple organic molecules through the cell wall from their environment.
Section 1 Overview of Fungi Chapter 26 Characteristics, cont…Structure of Fungi • Fungi are made up of short filaments called hyphae. • Mats of hyphae are called mycelium. • Some species have partitions called septa in their hyphae, making individual cells. • Coenocytic hyphae don’t have septa • Fungal cell walls contain chitin rather than cellulose, which is found in plant cell walls. • Dimorphism: the ability of some fungi to exist in two different forms – single cell or mycelial • Due to changes in temperature or nutrients
Section 1 Overview of Fungi Chapter 26 Characteristics of Fungi Click below to watch the Visual Concept. Visual Concept
Section 1 Overview of Fungi Chapter 26 Hyphae in Fungi
Section 1 Overview of Fungi Chapter 26 Body Structure of Fungi Click below to watch the Visual Concept. Visual Concept
Section 1 Overview of Fungi Chapter 26 Reproduction Most fungi reproduce both asexually and sexually. Asexual Reproduction • Asexually, fungi produce thousands of genetically identical haploid spores, usually on modified cells of the hyphae. • When these spores are placed in favorable environmental conditions, they germinate and grow new hyphae, each of which can form a mycelium and produce thousands of new asexual spores.
Section 1 Overview of Fungi Chapter 26 Reproduction, continued • Asexually… • Sporangiophores: specialized hyphae that look like upright plant stalks • Sporangium: the sac at the top of the sporangiophore • Sporangiospores: spores inside each sporangium
Asexual Reproduction, continued • Conidia: spores formed without the protection of a sac • Conidiophores: tops of the stalk-like structure where conidia are formed • Penicillin and some cheeses are produced from these fungi
Asexual Reproduction cont… • Fragmentation: a process where septate hyphae dries and shatters, releasing cells that act as spores (example: Athlete foot fungus) • Budding: asexual process in which part of a yeast cell pinches off to produce a small offspring cell
Section 1 Overview of Fungi Chapter 26 Reproduction, continued Sexual Reproduction • Fungi occur in mating types that are sometimes called minus and plus. (no male/female) • When two different mating types of the same species encounter one another, the hyphae of one mating type fuse with the hyphae of the opposite mating type. • These fused hyphae give rise to a specialized structure, which produces and scatters genetically diverse spores.
Section 1 Overview of Fungi Chapter 26 Sexual Reproduction Click below to watch the Visual Concept. Visual Concept
Section 1 Overview of Fungi Chapter 26 Evolution • Fungi evolved about 460 million years ago. • First fungi were unicellular and clung together after mitosis • Came around about the same time as early plants • Fungi probably evolved from endosymbioticprokaryotes and then adapted to various terrestrial environments.
Section 2 Classification of Fungi Chapter 26 Objectives • Listcharacteristics that distinguish three phyla of fungi. • Comparethe life cycles of zygomycetes, basidiomycetes, and ascomycetes. • Distinguishbetween mycorrhizae and lichens. • Explainthe importance of mycorrhizae and lichens to the environment.
Section 2 Classification of Fungi Chapter 26 Types of Fungi Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Phylum Zygomycota • The phylum Zygomycota is coenocytic (their hyphae lack septa). • Asexual sporangiospores form within sacs called sporangia. • Sexual reproduction results in zygospores.
Phylum Zygomycota • Mostly terrestrial organisms found in organic rich soil • Hyphae coenocytic - distinguish the following: • Contain rhizoids: hyphae that anchor into the surface and produce digestive enzymes • Contain stolons: hyphae that grow across the surface
Phylum Zygomycota (cont.) • Example: common bread fungus • Reproduce sexually through conjugation • Hyphae combine at tip to form gametangium, once they fuse, forms a zygosporangium, which undergoes meiosis and eventually produces a zygospore, from which a sporangiophore and a sporangium with haploid spores develops
Section 2 Classification of Fungi Chapter 26 Life Cycle of Zygomycetes
Section 2 Classification of Fungi Chapter 26 Asexual Reproduction in Zygomycetes Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Sexual Reproduction in Zygomycetes Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Phylum Basidiomycota • The phylum Basidiomycota includes mushrooms. • Mushrooms are spore-bearing, aboveground sexual reproductive structures called basidiocarps. • Entire mushroom: basidiocarp---Stem: stalk, flattened structure: cap, underneath cap: gill (location of basidia) • Basidiocarps produce small, clublike reproductive structures called basidia,on which basidiospores form.
Phylum Basidiomycota (cont.) • Basidia contain two nuclei (dikaryotic) which fuse together eventually forming four basidoiospores • Basidiospores germinate to produce haploid mycelia that grow underground • When hyphae of compatible basidoiospores encounter one another, hyphae may fuse forming a new basidiocarp
Section 2 Classification of Fungi Chapter 26 Structure of a Mushroom
Section 2 Classification of Fungi Chapter 26 Parts of a Mushroom Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Life Cycle of Basidiomycetes
Section 2 Classification of Fungi Chapter 26 Sexual Reproduction in Basidiomycetes Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Phylum Ascomycota or sac fungi… • …The most numerous of the fungi • Distinguished by the presence of saclike compartments where sexually produced spores form • Example: sac fungi, yeast, penicilliium mold • Yeast are unicellular Ascomycota and they reproduce asexually by budding. • Yeast are used in brewing, baking, and genetic engineering, and gasohol production
Phylum Ascomycota or sac fungi…(cont.) • Hyphae form a cup-shaped ascocarp, in which ascospores form. • The female gametangium (ascogonium) and the male gametangium – (antheridium) form a tube between them where the nuclei of the male crosses and fuses forming a cup (ascocarp) • Sacs within the ascocarp called asci form spores called ascospores
Section 2 Classification of Fungi Chapter 26 Life Cycle of Ascomycetes
Section 2 Classification of Fungi Chapter 26 Penicilliium Mold
Section 2 Classification of Fungi Chapter 26 Asexual Reproduction in Ascomycetes Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Sexual Reproduction in Ascomycetes Click below to watch the Visual Concept. Visual Concept
Section 2 Classification of Fungi Chapter 26 Phylum Ascomycota, continued Deuteromycota • Fungi that do not have a sexual stage are classified in a group calledfungi imperfecti,or deuteromycota.
Section 2 Classification of Fungi Chapter 26 Mycorrhizae and Lichens • Mycorrhizae are symbiotic structures that form between plant roots and a fungus. • The fungus provides certain ions and other nutrients to the plant and, in turn, the fungus gets sugars from the plant.
Mycorrhizae (continued) • A symbiotic structure formed between fungi and plant roots • 80% of vascular plants have this on their roots • Fungus gives nitrogen, phosphate, and other ions to plant- plant provides glucose
Section 2 Classification of Fungi Chapter 26 Lichens… • …represent symbiotic relationships between fungi and photosynthetic organisms, such as cyanobacteria or green algae. • Fungus provides shelter and moisture, while algae provides glucose
Section 3 Fungi and Humans Chapter 26 Objectives • Describethree ways that fungi cause disease in humans. • Listthree ways that fungi contribute to good health. • Provideexamples of fungi’s industrial importance. • Listthree types of food that fungi provide.
Section 3 Fungi and Humans Chapter 26 Human Fungal Diseases • Fungi can cause disease in humans when humans inhale airborne spores, when they eat food contaminated by toxic fungi, when toxic fungi come in contact with skin, or when they accidentally eat poisonous mushrooms.
Section 3 Fungi and Humans Chapter 26 Human Fungal Diseases Common Fungal Infections • Examples of common fungal infections include ringworm, athlete’s foot, and yeast infection.
Section 3 Fungi and Humans Chapter 26 Human Fungal Diseases, continued Other Fungal Illnesses • Spores being inhaled cause respiratory system problems • Pathogenic fungi that cause serious disease include Histoplasmacapsulatum, Blastomycesdermatitidis, and Coccidioidesimmitis. • H. capsulatum is associated with bird feces. • The eating of poisonous mushrooms • Aflatoxins: poisons produced by some species- can cause liver cancer
Section 3 Fungi and Humans Chapter 26 Fungi in Industry • Various fungi are used in the production of vitamin B2, cortisone, penicillin and other antibiotics, and some genetically engineered drugs. • Yeast are used to produce ethanol (alcohol) for the automobile fuel gasohol
Section 3 Fungi and Humans Chapter 26 Fungi in Industry, continued Fungi and Food Industries • Fungi are used in the production of familiar foods such as cheeses, bread, beer, wines, and soy products.
Chapter 26 Standardized Test Prep Multiple Choice 1. What are fungi that feed on decaying organic matter called? A. parasites B. mutualists C. symbionts D. saprophytes
Chapter 26 Standardized Test Prep Multiple Choice, continued 1. What are fungi that feed on decaying organic matter called? A. parasites B. mutualists C. symbionts D. saprophytes
Chapter 26 Standardized Test Prep Multiple Choice, continued 2. Lichens represent a symbiotic association between a fungus and which other type of organism? F. an alga G. a plant H. a mold J. a rhizoid