Lecture on fungi [11 25-13 monday]

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Lecture on fungi [11 25-13 monday]

  1. 1. Lecture on Fungi 11/25/13 Monday
  2. 2. Characteristics • • • • nonphotosynthetic Most are saprobes (feed on dead things) Cell wall made of chitin Genetically more similar to animals
  3. 3. Importance • • • • Decomposer and recycler of nutrients Consumed as food and food production Truffles, morels, mushroom Antibiotic: penicillin
  4. 4. Antibiotics • Cyclosporin prevent organ rejection • Statin lowers cholesterol • Penicillin
  5. 5. Mutual symbionts of pants • Mycorrhizae • lichens
  6. 6. lichen • Mutual symbiont of algae • Indicator of air pollution • Source of dyes (litmus)
  7. 7. Three forms of lichen (Know for lab exam) 1. Crustose: crustlike, growing tight against the substrate. 2. Foliose: leaflike, with flat sheets of tissue not tightly bound 3. Fruticose: free-standing branching tubes.
  8. 8. Mycoses • Agents of disease
  9. 9. Four Fungal diseases 1. 2. 3. 4. Thrush: yeast infection Histoplasmosis : lung infection Aspergillosis : mold in your house Cryptococcus /Valley fever: can lead to pneumonia and meningitis
  10. 10. ergotism • Clavicles fungus • Salem witch trials
  11. 11. Sporotrichosis: rose gardener’s disease • Fungal antibiotics are harmful; humans and fungi are eukaryotes. Bacterial infections are better to treat because they are prokaryotes
  12. 12. Tinea Infections (Ringworm) • Infection on skin and nail’s keratin
  13. 13. Claviceps purpurea, cause of ergotism
  14. 14. Plant diseases caused by fungi 1. Rust 2. Apple Scab 3. smut
  15. 15. cellular • Unicellular (yeast) • Multicellular (mold) • Some are yeast inside and mold outside the body
  16. 16. Structure • Mycelia: networks of branched hyphae (cells) • Septum (cell wall) separating the hyphae • Coenocyte fungi lack septa and cellular contents can flow between the hyphae
  17. 17. Septate hyphae • Septum: a cross-wall formed in association with the mitotic division of a cell, laid down between the cells, usually at regular intervals.
  18. 18. Coenocytic hyphae • multinucleate mass of protoplasm resulting from repeated nuclear division unaccompanied by cell fission
  19. 19. Types of mycorrhizae fungi • Ecto : grow into the extracellular species of the root cortex (truffle) • Endo: grow into the root cell (orchid)
  20. 20. Reproduction • Plasmogamy: union of two parent mycelia • Heterokaryon: cell or mycelium in some fungi that do not result in the fusion of two nuclei • Dikaryotic: the nucleus pair off two to a cell
  21. 21. Karyogamy (nuclear fusion) • Produce diploid cells • Takes a long time • 2n phase is short-lived and undergo meiosis, producing 1n spores
  22. 22. sporangium • Fungal structures where asexual spores are produced • exam
  23. 23. budding • Simple cell division in which yeast repouce asexually
  24. 24. Imperfect fungi/deuteromycetes • Some fungi have no known sexual stage
  25. 25. Evolution • Fungi descended from protists • Fungi and Animalia are sister kingdoms
  26. 26. Groups you must know 1. 2. 3. 4. 5. Chytridiomycota: earliest fungi Zygomycota Glomeromycota Ascomycota Basidiomycota
  27. 27. Chytridiomycota: earliest fungi • • • • Found in water Saprobic or parasitic B. dendrobatids: decline of frog population Chytrids diverged earliest
  28. 28. Zoospores: flagellated spores • Only chytrids have zoospores
  29. 29. Zygomycota • • • • Asexual and sexual spores Zagospore (sexual) Sponragiospores (asexual spores) Very cold/heat tolerant, responsible for food spoilage • Black bread mold Rhizopustoloniser • pilobolus
  30. 30. Life cycle • Zygomycota
  31. 31. glomeromycota • Arbuscular mycorrhizae: endo • 80% of all vascular plants have arbuscular mycorrhize • Reproduce asexually • Help plants absorb phosphorous and help a crucial role in colonization of land by plants
  32. 32. Ascomycetes (cup fungi) • Asci: sexual spores that are found in saclike structure • Reproduce sexually • Many asci are found on the fruiting body called ascocarp • Ex. Truffle • Conodia: asexual spores • Conodiophore: structure
  33. 33. Penicillium conidiophores
  34. 34. Sporangium conidiophore
  35. 35. Aspergillus condiophore
  36. 36. Ascomycetes • Truffles, yeast, penicillin, morels
  37. 37. Ascomycetes • Fungal partner in lichen is an ascomycete
  38. 38. Basidiomycetes: typical mushroom • Basidium: structure where sexual spores (basidiospores) are produced • Gills with basidia
  39. 39. Reproduction of Basidiomycetes: typical mushroom • Sexual mostly resulting in dikaryotic fruiting bodies called basidiocarps (mushroom) • Karygomy occurs in the gills of the mushroom cap where basidium and basidiophores are found • Asexual reproduction is rare and occur via fragmentation • Ex. Club fungi, rust, smut, puff balls, shelf fungi, mushrooms
  40. 40. Basidiomycete life cycle • • • • • • • • • • • • Basidiomycetes – Fungi Key Points The basidiomycetes (phylum Basidiomycota) are comprised of roughly 30,000 species that include mushrooms, shelf fungi and puffballs. The basidium is a specific, club-shaped cell where karyogmay is carried out followed by meiosis. This gives rise to the name club fungus. A diploid nucleus is formed during karyogamy and then undergoes meiosis, resulting in four haploid nuclei. The basidium divides into four arms, with a single haploid nucleus in each that will develop into a basidiospore. The reproductive cycle of basidiomycetes has a long dikaryotic mycelium stage allowing for genetic diversity as a result of recombination. Basidiomycetes are particularly important in nature as decomposers of plant material, especially dead wood and trees. Terms basidium a small structure, shaped like a club, found in the Basidiomycota phylum of fungi, that bears four spores at the tips of small projections Karyogamy The fusion of two nuclei within a cell. Mycelium The vegetative part of any fungus, consisting of a mass of branching, threadlike hyphae, often underground. mycelium the vegetative part of any fungus, consisting of a mass of branching, threadlike hyphae, often underground
  41. 41. Glossary • http://bugs.bio.usyd.edu.au/learning/resourc es/Mycology/Glossary/glossary_a_b.shtml

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