1 / 12

Fungi

Fungi. Section 18-2. What is a Fungus?. They are heterotrophic eukaryotes with a cell wall They obtain food by extracellular digestion and absorption Enzymes are released to break down food particles outside their bodies Digested molecules are then absorbed. What is a Fungus?.

kelda
Download Presentation

Fungi

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fungi Section 18-2

  2. What is a Fungus? • They are heterotrophic eukaryotes with a cell wall • They obtain food by extracellular digestion and absorption • Enzymes are released to break down food particles outside their bodies • Digested molecules are then absorbed

  3. What is a Fungus? • Most are multicellular (except yeast) • Can be parasitic or decomposers • They look more like plants, but are technically more like animals: • They have cell walls like plants, but the cell wall is made of chitin not cellulose (chitin is found in the exoskeletons of insects) • They store energy as the starch glycogen, like animals and are heterotrophic

  4. Characteristics of Fungi • Evolved around 430 million years ago • All multicellular fungi have the same basic structure: • Hypha (pl. hyphae) – a threadlike filament whose cells have varying numbers of nuclei • Mycelium – mass of hyphae that grows into the food source (this is the part that secretes the enzymes for digestion) • Fruiting body – the reproductive part of the fungus that produces spores

  5. Reproduction in Fungi • Can be asexual: • Some produce spores • Some reproduce by fragmentation of hyphae

  6. Reproduction in Fungi • Can be sexual: • There are two mating types - + hyphae and – hyphae • When opposite hyphae meet, some of their filaments fuse • Their nuclei then fuse, undergo meiosis, and produce spores

  7. Types of Fungi • Phylum Zygomycota (called zygomycetes) • Also called bread molds or common molds • Reproduction has two phases, one asexual and one sexual • An example is Rhizopus stolonifer (black mold)

  8. Types of Fungi • Phylum Ascomycota (called ascomycetes) • Also called sac fungi • 30,000+ species of mildews, molds, and yeasts • Examples include truffles, baker’s yeast

  9. Types of Fungi • Phylum Basidiomycota (called basidiomycetes) • Fruiting bodies form mushrooms (above ground) • Many are delicious, some can be poisonous

  10. Types of Fungi • Phylum Deuteromycota (called deuteromycetes) • Also called “imperfect” fungi because scientists have never been able to identify the sexual stage of their life cycle • Example is Penicillium, which is used to make the antibiotic penicillin; also the fungus that causes athlete’s foot

  11. Lichens • Look like moss, usually seen growing on tree trunks or rocks • Not actually a single organism – represents a symbiotic partnership between a fungus and some photosynthetic organism, like a bacterium or algae • The autotroph performs photosynthesis, which provides nourishment for the fungus • The fungus provides the autotroph with water and minerals that it removes from the rock or the tree

More Related