Fungi

Characteristics

Multicellular (few exceptions like yeast) Eukaryotic Heterotrophic, break down food then absorb,

saprotrophic Some are parasitic, cause disease Economically important, food, fermentation,

medicines Mutualistic relationships

Structure of Fungi

Mycelium – make up body of most fungi Hyphae – network of fibers that make up

mycelium, increase surface area for fungi Some have septa – cross walls, have pores Non-septate fungi, multinucleated

Cells contain chitin in cell wall, lack chloroplasts

Non motile, not flagella, grow toward food source

Reproduction

Sexual haploid hyphaedikarytoicdiploid zygote Hyphae from 2 different fungi meet and fuse Produce windblown spores to insure dispersal

Spore – reproductive cell that develops into a new organism without the need to fuse with another reproductive cell.

Reproduction

Asexual Production of spores by specialized part of single

mycelium. Fragmentation and budding (yeast) can occur

Fungi Evolution

570 mya Maybe evolved from red algae (both lack

flagella) Thought to be part of Plantae and Protista

kingdoms Fungal groups are classified according to

differences in life cycle and type of structure that produces spores.

Phyla Zygomycota

Saprotrophic, in soil and food, some parasitic Black bread mold – Rhizopus stolonifer

Stolon are horizontal hyphae on surface of bread Rhizoids grow into bread, anchor the mycelium

and carry out digestion. Sporangium – produces spores called

sporangiospores Zygospore – seen in sexual repro.

Forms prior to meiosis and production of spores 23.3 page 401

Phylum Ascomycota

Sac fungi Sexual ascomycetes (yeasts, red bread molds,

mildews, morels, truffles, chestnut blight, ergot) Asexual ascomycetes, no sexual repro. observed,

(Aspergillus, Candida and Penicillium molds) Penicillium has been renamed Talaromyces

Essential to digesting not easily decomposed materials such as cellulose, jet fuel)

Sac Fungi

Symbiotic lichens (with algae), plant roots (mycorrhizae)

Reproduction – conidiospores (spores) Ascus – fingerlike sac that develops during

sexual reproduction Fruiting body – reproductive structure where

spores are produced and release.

Economical benefits/ non-benefits Food – beer, wine, cheese, coke Medical – antibiotics, steroids, cyclosporin Disease – ringworm, rose gardener’s

disease, Chicago’s disease… Yeasts – Candida - infections Molds – Aspergillus – soy sauce, pathogenic

to humans, carcinogen

Basidiomycota

Club fungi – mushrooms, toadstools, puffballs Food, disease (smuts and rusts)

Reproduction – usually sexually Basidium – club shaped structure in which spores

develop

Symbiotic relationships

Lichens – fungus and green algae or cyanobacteria. Thought of as mutualistic but may be parasitic, algae do

not benefit 3 types, environmental indicators, live in extreme

conditions

Mycorrhizae – soil fungi and roots of most plants Plants more successful in poor soils Helps plants acquire mineral nutrients