Fungi

Characteristics

·         Typically multicellular, some unicellular forms exist

·         Heterotrophic by absorption

·         Most harmless consumers

·         Some parasites

·         Some mutualists

 

Evolution:

 

 

Structure:

·         Hyphae:

 

·         Mycelium:

 

·         Reproductive structures:

 

·         Cells:

o   Chitin, not cellulose in cell walls

o   Cells can be septate, or nonseptate.

o   Energy reserve is glycogen, not starch.

·         Movement:

o   Nonmotile

o   Move by growing

 

Reproduction:

·         Asexual: 

o   Haploid spores by fission or budding

o   Mold

o   Yeast

·         Sexual:

o   Fusion of cells

o   Heterokaryotic stage

o   Meiosis to produce haploid spores

o   Spores germinate to hyphae

 

Types of Fungi:

·         Chytrids: flagellated spores

 

·         Zygomycetes

o   Zygospore contains spores that will divide by meiosis.

o   Black bread mold

o   Pilobus

 

·         Glomeromycetes

o   Symbiotic with plants

·         Ascomycetes: Sac Fungi

o   Ascus is contained inside an ascocarp.

o   Ascus produces spores during sexual reproduction.

o   Each ascus produces 8 ascospores.

o   Includes yeast, some molds, and morels.  Make up lichens and mycorrhizae.  

o   Yeasts:

§  Brewer’s yeast:

§  Candidaalbicans

o   Molds:

§  Aspergillis

§  Penicillin

§  Tinea

o   Morels

 

o   Ergot

 

o   Lichens

§  Fungus + cyanobacterium OR green alga

§  Survive in extreme environments.

§  Hyphae penetrate photosynthetic cells and transfer nutrients to rest of fungus.

§  Reproduce asexually by releasing fragments containing an algal cell and hyphae.

§  Symbiosis or parasitism???

o   Mycorrhizae

§  Fungus + plant root

§  Fungus enters cortex of root, but not plant cells.

§  Helps root absorb more minerals, plant provides it with carbohydrates.

·         Basidiomycetes: Club Fungi

o   Named for club-shaped pore producing structure, the basidium.

o   Key decomposers

o   Include 2 major groups:

§  Those that produce large above ground fruiting structures (basidiocarps) for sexual reproduction.

·         Table mushrooms

 

·         Destroying angels

 

·         Magic mushrooms

 

 

§  Those that produce small, numerous spores resembling smut or rust.

·         Smuts

 

·         Rusts