BIO 206SPRING SEMESTER 2019INSTRUCTOR: DR. RITA MOYES22 February 2019FungiFungi-distinct group-mushrooms, blights, smuts, molds, yeasts, etc● Neither plants nor animals● Resemble plants because:○ Have a cell wall○ Nonmotile● Unlike plants they lack chlorophyll and cannot use photosynthesis● Spore Bearing organisms with absorptive nutrition can reproduce sexually andasexually● The science discipline dealing with fungi is called mycology● >100,000 known species of fungi found in various environments● Primarily terrestrial environments● Can adapt to environment extremes○ Extreme temperature○ Extreme pH● Some are pathogenic=infect plants and animals○ 30%○ Living tissues○ Grow best in:■ dark/cool/ moist conditions● Majority of fungi are saprobes/saprophytic○ Can grow pretty much anywhere there’s nutrients1○ 70%○ Live off dead tissuesFungi● Majority are unicellular or colonial; a few have cellular specialization-mushrooms● Divided into 2 groups:○ Macroscopic fungi (mushrooms, puffballs)■ Can see with eyes○ Microscopic fungi■ Yeasts■ MoldsMicroscopic Fungi● Exist in two morphologies:○ Yeast■ Round to oval shaped & undergo asexual reproduction by budding■ Are larger than bacteria■ Some form pseudohyphae=string of budding cells■ Hyphae=threadlike filaments■ Circles are bud scars○ Mold■ Consists of filaments called hyphae=thread-like cells; tubularfilaments● Overall:○ Some fungi exist in either microscopic form■ Dimorphic● Happens at different environmental conditionsMacroscopic view● Colonies of yeast→ like those of bacteria: soft, uniform texture and appearance● Colonies of mold→ look cottony, hairy, or velvety● The woven, intertwining mass of hyphae that makes up the body or colony of amold=mycelium2Hyphae-classified by structure● Nonseptate hyphae○ Consist of one long continuous cell=no cross walls or divisions, so it justcontinues to grow and get more organelles○ Cytoplasm and organelles move freely from one region to another with eachhyphae having multiple nuclei● Septate hyphae○ Cross walls○ Divisions varies from solid partitions to partial walls with small pores■ If pores are present, allows organelles, fluid and nutrients to movealong the hyphaeHyphae-classified by function● Vegetative hyphae○ Grows horizontally along the surface/substrate/food source○ Penetrate the substrate-release enzymes for food absorption● Reproductive or aerial hyphae○ Orient vertically from the vegetative mycelium○ Produce and support spores■ Involved in sexual and asexual reproductionSpore (not the same thing as endospores)● Fungal spores are responsible for:○ reproduction/multiplication○ Survival○ Dissemination○ Producing genetic variations● Dispersed widely through the environment by air, water, and living things● Normal outdoor air can contain up to 100,000 fungal spores per cubic meter● Moist air contains up to a billion spores per cubic meter● Upon encountering a substrate, a spore will germinate and produce a new funguscolony in a very short time3● Fungi are very diverse and are classified and identified by their spores and sporestructuresRoles of Fungi-impact on humans and environment● Adverse impact○ Mycoses, allergies, toxin production○ Destruction of crops and food shortages● Beneficial impact○ Decomposers of dead plants and animals○ Helps recycle nutrients back into the environment○ Sources of antibiotics, alcohol, organic acids, vitamins○ Used in making food and genetic studies1. Fungal Nutrition-saprobes○ Majority (70%) are harmless saprobes=they get their nutrients from deadtissues○ Extremely widespread distribution in many habitats○ Fungi act as decomposers○ Degrade complex organic material in the environment to simplecompounds=recycling various compounds into the environment for our use○ Fungi possess enzymes that allow it to break down any organic material○ Mycorrhizae-beneficial fungi associated with plant rods■ Live in symbiotic relationship, allow H2O and nutrients available toeach other2. Parasitic Fungi○ Use the bodies living animals or plants○ Can reach host because spores are carried by wind or can reach hostbecause spores are carried by wind or water or on insects and animals■ Fungi plant diseases-wilts, mildews,blights,rusts, and smuts■ Diseases of domestic birds and animals lead to economic losses.● Aspergillosis (chickens) and slobbers (cows) are fungal diseasesfrom parasitic