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The Kingdom Fungi. What is a Fungus?. Fungi are eukaryotic heterotrophs Decomposers known as saprophytes Cell walls made up of chitin Some are parasites – Ex. Athlete’s Foot, Ringworm Some are symbionts – Ex. Lichen Fungi do not ingest food, they release enzymes and absorb nutrients.
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What is a Fungus? • Fungi are eukaryotic heterotrophs • Decomposers known as saprophytes • Cell walls made up of chitin • Some are parasites – Ex. Athlete’s Foot, Ringworm • Some are symbionts – Ex. Lichen • Fungi do not ingest food, they release enzymes and absorb nutrients
Structure and Function of Fungi • All fungi are multicellular (except yeasts, which are unicellular) • Composed of tiny filaments called hyphae. Each hyphae is only one cell thick. • Many hyphae tangled together into a thick mass called a mycelium. Mycelium absorbs nutrients for fungi • What you see above ground is the fruiting body, or reproductive structure of fungi. Fruiting body develops from mycelium underground. • Why is the fruiting body above ground? • Why is the mycelium underground?
The Structure of a Mushroom Fruiting body “Gills” would be located under here – where spores can be found Hyphae Mycelium This is a typical Club fungi
Reproduction and Spreading of Fungi • Most fungi reproduce both sexually and asexually • Asexually – hyphae break off and grow on their own or scatter spores • Some fungi lure animals with scent to help them disperse their spores over distances • Fragmentation, spores, conjugation
Classification of Fungi • Classified according to structures and method of reproduction • Four phyla: • Zygomycota – Common Molds • Ascomycota – Sac Fungi • Basidiomycota – Club Fungi • Deuteromycota – Imperfect Fungi
Nuclei Cell wall Cytoplasm Cross wall Nuclei Cytoplasm Cell wall Phylum Zygomycota – Common Molds - Zygomycetes • Terrestrial • Hyphae lack cross walls – they look like one big cell Hyphae With Cross Walls Hyphae Without Cross Walls
Phylum Zygomycota – Common Molds - Zygomycetes • Example: Black bread mold, Rhizopus stolonifer • Black bread mold has root-like hyphae that penetrates the surface of bread – called rhizoids
Zygospore (2N) Sporangium Gametangia Spores (N) Sporangium Zygospore (2N) + Mating type (N) Stolons Spores (N) - Mating type (N) Sporangiophore Rhizoids Sexual and Asexual Reproduction of Rhizopus FERTILIZATION MEIOSIS Sexual Reproduction Asexual Reproduction Diploid Haploid
Nuclei Cell wall Cytoplasm Cross wall Nuclei Cytoplasm Cell wall Phylum Ascomycota – Sac Fungi • Largest phylum – 30,000 species • Nuclei separated by cross walls • Named for ascus – reproductive structure containing spores • Examples: Yeast (unicellular), cup fungi Hyphae With Cross Walls Hyphae Without Cross Walls
Fruiting body (N + N) Hyphae (N + N) Ascus (N + N) Zygote (2N) Hyphae (N) Asci Gametangia + Mating type (N) - Mating type (N) Ascus Conidia (N) 8 Ascospores (N) Hypha (N) Conidiophore Hypha (N) Sexual and Asexual Reproduction of an Ascomycete Diploid Haploid FERTILIZATION HYPHAE FUSE Sexual Reproduction Asexual Reproduction
Examples of Phylum Ascomycota Aleuria aurantia Yeast Cookeina colensoi
Phylum Basidiomycota – Club Fungi • Gets name from specialized reproduction structure resembling a club, called basidium – found on the underside of mushroom cap in the gills • One mushroom may produce 1 billion spores • Some are edible, some are toxic • Examples: Mushrooms, toadstools • Most elaborate life cycle of all the fungi
Fruiting body (N + N) Gills lined with basidia Gills Cap Stalk Button Base Basidia (N + N) Secondary mycelium (N + N) Primary mycelium (N) Zygote (2N) - Mating type (N) + Mating type (N) Basidiospores (N) Sexual and Asexual Reproduction of Basiomycete FERTILIZATION HYPHAE FUSE Haploid Diploid MEIOSIS
Examples of Phylum Basidiomycota Orange Jelly Pigskin Poison Puffball Fly Agaric Bird’s Nest Fungus Star Stinkhorn Shelf Fungus
Phylum Deuteromycota – Imperfect Fungi • Varied phylum • Not much known about fungi placed in this phylum • Example: Penicillium – antibiotics • Do not appear to have sexual reproduction
Examples of Phylum Deuteromycota Penicillium notatum Ringworm Athlete’s Foot
Deuteromycota Zygomycota Ascomycota Basidiomycota Fungi are divided into the phyla includes includes includes includes Common molds Sac fungi Club fungi Imperfect fungi