1. Fungi

2. Basic characteristics of Fungi Eukaryotic Multicellular (except yeast) Heterotrophic Mode of nutrition: absorbtive Secrete hydrolytic enzymes Digestion occurs externally Composition of cell walls differs-chitin

3. CHARACTERISTIC A. Filamentous Growth Form B. 1.Hyphae A. a. stolons B. b. rhizoids 2.Mycelium a. If strung end-to-end would be many meters long b. Surrounds and penetrates substrate c. Composition of cell wall-Polysaccharide plus chitin (not cellulose) 1.Same component of arthropod exoskeleton 2.More resistant to bacterial degradation

4. Economic Value of Fungi A.Harmful- Cause decay, rot, spoilage and serious plant and animal diseases B.Beneficial 1. Manufacture of bread and beer 2. Flavor cheese, wine and other foods 3. Industrial production of acids, antibiotics and chemical syntheses 4. Detoxify environment 5. Mycorrhizae facilitate absorption of essential nutrients by plant roots

5. Fungal Structures Mycelium: Mostly underground; feeding body composed of interwoven: Hyphae: threadlike structures Septa: divide hypae into cells Haustoria: tips of hyphae Cell walls: chitin Some are coenocytic (aseptate) See fig. 31.1 and 31.2

6. Life cycle/Reproduction May be asexual or sexual Some only have sexual repro in response to an environmental change

7. ZYGOMYCETES Structure a.Hyphae 1. Stolon-grow horizontally 2. Rhizoids- grow down 3. Sporangiophore-grow upward b.Sporangium(2N) 1. Form spores(N) 2. Meiosis

8. ZYGOMYCETES

9. BASIDIOMYCETES 1. Types a. Mushrooms, jelly fungi, puffballs, rusts and smuts b. Include edible and poisonous varieties 2.Reproduction a.Sexual b.Asexual reproduction rare in basidiomycetes 3. Structures a. Stipe b. Gills c. Cap d. Annulus

10. BASIDIOMYCETES

11. ASCOMYCETES 1. Types a. Beneficial forms include yeast, penicillin, morels and truffles, cheese mold, neurospera b. Harmful forms include chestnut blight, Dutch elm disease, Clavis purpurea-LSD c. Reproduction 1. Asexual reproduction is common 2.Sexual

12. ASCOMYCETES

13. DEUTEROMYCETES 1.Fungi that Have Lost the Ability to Reproduce Sexually 2.Have great economic importance –a. Many are human and plant pathogens –1.ring worm –2.athletes foot b.Others produce important chemicals including penicillin V.Fungal Relatives

15. MYCORRHIZAE b.Mycorrhizae 1. General characteristics a. Most plant roots associated with certain fungi b.Fungus aids in transfer of soil nutrients into roots c.Plant provides organic carbon to fungus 2. Advantages of mycorrhizial associations a.Plants more resistant to drought, cold and harsh conditions b.May provide better protection against acid precipitation c.Prevent accumulation of toxic metals d.Speed germination of orchid seeds e. Provide better growth in poor soils f. Present in early fossil plants g. Early soil lacking organic matter

16. FUNGAL RELATIVES A.Lichens 1.General Characteristics a.Mostly ascomycetes with green alga and/or cyanobacterium b.Specialized hyphae penetrate or envelop photosynthetic cells c.Fungal chemical signals direct photosynthetic metabolism d.Could be considered a form of controlled parasitism 2.Reproduction a.Via normal fungal sexual processes b.Photosynthetic cell reproduction generally asexual c.Asexual reproduction by fragmentation

17. 3. Ecology a. Inhabit cold, dry, generally harsh environments b. Help break rock surfaces and prepare habitat for other organisms c. Lichens with cyanobacteria can fix atmospheric nitrogen d. Survive adverse conditions by nearly halting metabolism e. First growth on barren rock-leads to soil 4. Lichens and Pollution a. Extremely sensitive to atmospheric pollutants b. Absorb substances dissolved in rain or dew c. Sensitive to sulfur dioxide an automobile pollutant d. Indicates radioactive pollution