Fungi

Eukaryotic organisms Heterotrophic Contain the polysaccharide chitin in their cell

walls Where once considered part of the plant

kingdom Evolved close to 900 million years ago

Classification of Fungi

Over 70000 species have been described Estimated to have over 1.5 million species

total Some phyla include:

• Mastigomycota – water moulds, chytrids

• Zygomycota – moulds (bread moulds, dung moulds)

• Basidiomycota – mushrooms, cap fungi

• Ascomycota – yeast, morrels, truffles

Fungi vs. Plants

Similarities

Eukaryotic, cell walls, anchored in soil or substrate

Reproduce asexually, sexually or both; stationary

Differences

Plants Fungi

One nucleus per cell Multiple nuclei

Autotrophs Heterotrophs

Starch for energy storage Little or no energy storage

Have roots No roots

Cellulose in cell walls Chitin in cell walls

Some reproduce by seed None reproduce by seed

Fungi nutrition

Feed by extracellular digestion As hyphae grow across its substrate,

digestive enzymes are released Macromolecules are broken down into

smaller molecules Smaller molecules are then absorbed into

the hyphae

Fungal Anatomy

Fungal Anatomy

Most fungi are invisible to the eye, as most of the fungus is in the soil or substrate

Some become visible when we see their fruiting bodies (eg. mushroom caps)

Mycellium – networks of hyphal threads. Some fungi are the largest organisms on

earth (an area of 2200 acres/ 8.9km2)

Importance of Fungi

Symbiosis – symbiosis is two different species each depending on eachother

Trees have fungi living in close quarters to their roots

Hyphae absorb minerals/nutrients, and release them to the roots

Fungus benefits by absorbing sugars and amino acids from the plant

Relationship is call mycorrhiza (hyphae/roots)

Mycorrhiza

The fungus Aspergillus glaucus growing on bread in a compost

heap.

Aspergillus fungus

The fungus is made up of fungal threads (hyphae, grey) with conidiophores (fruiting bodies, brown) at the

tip.

Candida albicans fungus

Cells of the yeast- like fungus Candida albicans. This fungus is a cause of yeas infections (candidiasis). It is normally present on human skin and on the mucous membranes of the mouth, respiratory and intestinal tracts and

the vagina.

Ergot

Ingestion of ergot causes poisoning (ergotism) in animals and humans, which can be fatal. Symptoms can include vomiting, gangrene and hallucinations. A number of medical drugs, as well as LSD, are derived from ergot

Dermatophyten - This fungus is the cause of athlete's foot (tinea pedis) and scalp ringworm (tinea capitus). Both of these contagious skin infections are spread by the fungus's spores (orange). Also seen here are the fungus' thread-like hyphae

structures (green).

Mildew

The fruiting bodies of a fungus growing in a compost heap. Compost is made by allowing a heap of vegetable trimmings, non- seeding weed plants and grass mowings to degrade. The resulting brown, crumbly compost is dug into soil to provide plants with

nutrients.

References

Pictures from:• http://www.eyeofscience.de/• www.thecapcrew.ca• http://www.apsnet.org/education/illustratedglossa

ry/PhotosI-M/mycorrhiza.htm