Friday, August 16, 2019

Kingdom Fungi

Chapter 21 Notes: Kingdom Fungi! Name_________________________ 21-1: The Kingdom Fungi A. What Are Fungi? Fungi include MANY DIFFERENT types of organisms From tiny yeast cells To the one of the largest organisms in the world! Fungi are: Multicellular (except for yeasts) Eukaryotic Heterotrophic Decomposers: decompose dead and decaying material -Recyclers! -Secrete enzymes OUTSIDE bodies – Absorb digested nutrients Hyphae: long, slender, root-like filament Septa: cross-walls across hyphae (not in all hyphae) Mycelium: mat of interwoven hyphae o Large surface area = max food absorptionFruiting body: reproductive structures, like mushrooms o Many can develop from same mycelium o â€Å"fairy rings† Entire mycelium is haploid! o (1 set of chromosomes) B. Structure & Function of Fungi Fungi cells have cell walls -Contain carbohydrate â€Å"chitin† also found in exoskeletons Unlike plants: -Fungi DON’T have chlorophyll -Fungi have chitin in cell walls (plants hav e cellulose) C. Reproduction in Fungi Most fungi reproduce BOTH asexually and sexually Asexual Reproduction: Sporangia at the tip of sporangiophores produce haploid spores Fragmentation (breaking off) of hyphae can also produce new mycelia Sexual reproductionFungi form hyphae of opposite â€Å"Sex† o Called â€Å"+† & â€Å"-â€Å" The + & – hyphae fuse and form gametangia: o Makes gametes o Form a diploid zygote o Zygote undergoes meiosis: haploid once again! D. How Fungi Spread Fungal spores travel VERY easily in the air All they need is a good â€Å"landing place† with moisture & food Some fungi have special adaptations for spreading spores 21-2: Classification of Fungi A. 4 Phyla of Fungi: Zygomycota Ascomycota Basidiomycota Deuteromycota Named for their reproductive structures! B. Phylum Zygomycota â€Å"Common molds† o On bread, cheese, etc. Black bread mold: Rhizopus stoloniferReproduce asexually (spores) & sexually (zygospores) C. Phylum Ascomycota â€Å"Sac Fungi† o Conidia form spores asexually o The ascus contains diploid spores in sexual reproduction Examples: yeast, cup fungi D. Phylum Basidiomycota â€Å"Club Fungi† 16,000 species: mushrooms, puffballs, bracket fungi, morels Club-shaped reproductive structure Spores form in basidia: o On the â€Å"gills† underneath mushroom cap Many wild mushrooms are poisonous! E. Phylum Deuteromycota â€Å"Imperfect Fungi† Fungi with NO KNOWN sexual stage Reproduction only asexually Ex: Penicillium; also pathogens like ringworm, athlete’s foot 1-3: Ecology of Fungi A. Fungi as Heterotrophs Most fungi are decomposers or saprobes Others are parasites (live on/in a living host) And others are symbionts: live in symbiosis with other organisms Pleurotus ostreatus is actually a carnivore captures & eats roundworms ALL fungi, though, are heterotrophs! B. Fungi as Decomposers External digestion: Fungi decompose matter by secreting enzymes o break i t down into simple organic molecules Fungus then absorb those molecules C. Fungi as Parasites Plants and animals (humans) are subject to fungal diseases Plants: o Corn smut o Mildew o Wheat rustHumans & animals: o Athlete’s foot o Yeast infections (Candida albicans) o Ring worm o Cordyceps (kills grasshoppers) D. Symbiosis Symbiosis is a â€Å"mutualistic† relationship in which BOTH partners benefit Lichens = algae (or cyanobacteria) + fungus o On rocks, dry environments Mycorrhizae = plant roots + fungus o -80% of plants might have these o Fungi help the plants get water & minerals o Plants provide fungi w/ energy E. Fungi & Food! Many foods are made using fungi! Yeast (Saccharomyces) is used to make bread, beer, wine Cheeses (Brie, Blue, Roquefort) are made using mold (Penicillium)

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.