Fun With Fungi 31

Characteristics Heterotrophs that acquire nutrients by ______________. Digestion occurs outside the body, secretion of hydrolytic enzymes. Nutritional modes: – ___________: (decomposers): absorb nutrients from nonliving organic material – ___________: absorb nutrients from host – ___________: reciprocal relationship with host

Characteristics Continued Bodies constructed of _______: thin tubular walls around cell cytoplasm/membrane Hyphae is woven together to form ______________. Form fits function: Large surface area for absorption (Can be huge underground –6.5 kilometers, thousands of years old) Cell walls built of __________ (polysaccharide) Nonmotile: extend hyphae to grow but can’t move

Types of Hyphae Septate: hypha cells divided into cross walls Aseptate: no cross walls Coenocytic: many nuclei in one cytoplasmic mass (no _____________) Haustoria: Penetrate host tissue Mycorrhizae: mutualistic with _______________.

Reproduction Asexual or sexual spores: sex contributes to genetic variation Two stages of syngamy: – Plasmogamy: fusion of ____________, nuclei pair up to form a dikaryon – Karyogamy: fusion of nuclei

Phylogeny Division Chytidiomycota (Chytrids) – Mainly aquatic, some saprobes and some parasites – Form flagellated zoospores, form coencytic hyphae Division Zygomycota (Zygote Fungi) – Terrestrial saprobes – Coencytic hyphae, form zygosporangia Division Ascomycota (Sac Fungi) – Marine and terrestrial, symbiotic (ex. Lichens, mycorrhizae) – Sexual spores is saclike asci, fruiting bodies Division Basidiomycota (Club Fungi) – Decomposers, mycorrhizae, parasites – Long lived dikarytoic mycelium, fruiting bodies, basidicarps

Fungal Forms MOLDS: rapid growth, asexual reproduction, saprobes or parasites, molds refers to asexual stage (uses include ________, fermenting ___________) YEASTS: unicellular, moist habitats, reproduce asexually by budding (uses include _______ and ___________ making) LICHENS: fungal mesh holding symbiotic organisms, algae gives fungus ________, cyanobacteria fixes _____________. (important for succession) MYCORRHIZAE: mutualism of plants and fungi (95% of vascular plants have mycorrhizae)

Applications Decomposers: make nutrients available to plants and animals (ex. Rot _______, fruits and veggies) Pathogens: Athletes foot, yeast infection, ringworm, lung infections – Asperigillus on improperly stored grain releases carcinogens called aflatoxins – Ergots formed from an ascomycete causes nervous spasms, hallucinations (Lysergic acid in LSD) Eating: mushrooms (don’t eat wild ones!!) and truffles