Heterotrophs - acquire nutrients by absorption

some unicellular (yeasts) - most multicellular

Nonmotile

Important in nutrient cycling- many pathogens

Formerly classified as plants - appear to be more closely related to animals - use of "Division" rather than "Phylum" reflects previous classification with plants

Decomposers (saprobes)

Symbiosis - mutualism with plants (mycorrhizae) - parasites of animals and plants

Hyphae - basic unit (resemble roots) - in most, divided into cells by septa (some aseptate - no septa) - cell walls of chitin (distinction from plants) - in parasitic forms, modified to form haustoria - allows penetration of host

Hyphae form mycelia - feeding "network" where nutrients absorbed - nutrients channeled to tips by cytoplasmic streaming - grow rapidly (up to 1 km/day) - concentrate on increasing absorptive area rather than girth

Most species reproduce asexually (under favorable conditions - produce clones) and sexually (under harsh conditions - increases genetic diversity)

Spores usually unicellular - some multicellular - dispersed primarily by wind and water

In sexual life cycle - syngamy (union of gametes) - plasmogamy (fusion of cytoplasm) produces dikaryotic stage (n+n) - karyogamy (fusion of nuclei) - meiosis (produces haploid spores)

Form flagellated spores (zoospores) - a protistan characteristic (formerly placed in Kingdom Protista)

Primarily aquatic

Saprobes and parasites (of protists, plants, invertebrates)

Most primitive group of fungi - belong to lineage that diverged earliest

Characterized by dikaryotic zygosporangia - resistant structures formed during sexual reproduction - hyphae coenocytic - septa only in reproductive cells

Mostly terrestrial (in soil & decaying organic material)

Many form mycorrhizae (mutualistic association with plant roots)

Includes black bread mold

Produce sexual spores in saclike asci - hyphae septate

Terrestrial, freshwater & marine

Important decomposers - many form mycorrhizae - important plant pathogens - some used for production of antibiotics (Penicillium spp)

Produce basidium (diploid clublike spore-forming structure) - fruiting bodies called basidiocarps (mushrooms, etc.)

Important decomposers (of all fungi, best at decomposing lignin) - many form mycorrhizae - important plant pathogens (rusts & smuts)

Molds, yeasts, lichens & mycorrhizae - terms that describe both morphological and ecological specialization - these are not taxa

Evolved independently among zygote fungi, sac fungi & club fungi

Rapidly-growing asexually-reproducing fungus

Mycelia grow as saprobes or parasites on great variety of substrates

Some molds may reproduce sexually later in life - the term mold applies only to asexual stages

Some have no known sexual stages - collectively known as deuteromycetes or Imperfect Fungi - some of these predatory

Sources of antibiotics (e.g., Penicilium) - fermentation of cheese

Unicellular - inhabit liquid or moist environments

Reproduce sexually (ascomycetes, basidiomycetes) or asexually (Imperfect fungi)

Includes the most important domesticated fungus - brewer’s yeast (Saccharomyces) - also potentially important human pathogens (Candida)

Mutualistic relationship between fungi (most commlnly ascomycete; also basidiomycete) and algae (usually green algae or cyanobacteria) - alga provides nutrients; fungus provides protection

Important as "pioneers" on newly cleared rock and soil - makes succession of plants possible - important as food for wildlife

Lichens given scientific names (of the fungus) - over 25,000 described species

Mutualistic relationship between fungi and plant roots - includes members of Basidiomycota, Ascomycota & Zygomycota

Greatly increases absorptive area of plant root system

Extremely important - over 95% of vascular plants have mycorrhizae - about 50% of mushroom-forming basidiomycetes live as mycorrhizae with oak, birch and pine

Important as decomposers and symbionts

Important elements of food web

Pathogens - 10% to 50% of world’s fruit crops lost each year due to fungal pathogens - human pathogens include aflatoxin (Aspergillus) and ergots produced by ascomycetes (toxins and illicit drugs such as LSD)