The Kingdom Fungi

What is a Fungus?

• Fungi are eukaryotic heterotrophs

• Decomposers known as saprophytes

• Cell walls made up of chitin

• Some are parasites – Ex. Athlete’s Foot, Ringworm

• Some are symbionts – Ex. Lichen

• Fungi do not ingest food, they release enzymes and absorb nutrients

Structure and Function of Fungi

• All fungi are multicellular (except yeasts, which are unicellular)

• Composed of tiny filaments called hyphae. Each hyphae is only one cell thick.

• Many hyphae tangled together into a thick mass called a mycelium. Mycelium absorbs nutrients for fungi

• What you see above ground is the fruiting body, or reproductive structure of fungi. Fruiting body develops from mycelium underground.– Why is the fruiting body above ground?– Why is the mycelium underground?

The Structure of a Mushroom

Mycelium

Fruiting body

Hyphae

This is a typical Club fungi

“Gills” would be located under here – where spores can be found

Reproduction and Spreading of Fungi

• Most fungi reproduce both sexually and asexually

• Asexually – hyphae break off and grow on their own or scatter spores

• Some fungi lure animals with scent to help them disperse their spores over distances

• Fragmentation, spores, conjugation

Classification of Fungi

• Classified according to structures and method of reproduction

• Four phyla:– Zygomycota – Common Molds– Ascomycota – Sac Fungi– Basidiomycota – Club Fungi– Deuteromycota – Imperfect Fungi

Phylum Zygomycota – Common Molds - Zygomycetes

• Terrestrial

• Hyphae lack cross walls – they look like one big cell

Hyphae Without Cross Walls

Nuclei

Cell wall

Nuclei

Cytoplasm

Cross wall

Cell wall

Cytoplasm

Hyphae With Cross Walls

Phylum Zygomycota – Common Molds - Zygomycetes

• Example: Black bread mold, Rhizopus stolonifer

• Black bread mold has root-like hyphae that penetrates the surface of bread – called rhizoids

Phylum Ascomycota – Sac Fungi

• Largest phylum – 30,000 species• Nuclei separated by cross walls• Named for ascus – reproductive structure containing

spores• Examples: Yeast (unicellular), cup fungi

Hyphae Without Cross Walls

Nuclei

Cell wall

Nuclei

Cytoplasm

Cross wall

Cell wall

Cytoplasm

Hyphae With Cross Walls

Examples of Phylum AscomycotaYeast

Cookeina colensoi

Aleuria aurantia

Phylum Basidiomycota – Club Fungi

• Gets name from specialized reproduction structure resembling a club, called basidium – found on the underside of mushroom cap in the gills

• One mushroom may produce 1 billion spores

• Some are edible, some are toxic• Examples: Mushrooms, toadstools• Most elaborate life cycle of all the fungi

Examples of Phylum Basidiomycota

Orange Jelly Pigskin Poison Puffball Fly Agaric

Star Stinkhorn

Shelf Fungus

Bird’s Nest Fungus

Examples of Phylum Basidiomycota

Laetiporus sulphureus: The Chicken of the Woods

Phylum Deuteromycota – Imperfect Fungi

• Varied phylum

• Not much known about fungi placed in this phylum

• Example: Penicillium – antibiotics

• Do not appear to have sexual reproduction

Examples of Phylum Deuteromycota

Penicillium notatum Ringworm

Athlete’s

Foot

are divided into the phyla

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Fungi

Common molds

Imperfect fungi

Sac fungiClub fungi

AscomycotaZygomycota Basidiomycota Deuteromycota