fungi diversity 2005 - university of arizona diversity 2005.pdf · • ascus – reproductive...

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Diversity of Fungi Diversity of FungiI. Intro and General biology

A. Defining fungi B. Feeding strategiesC. The fungal body

II. Fungal diversity – (table 31.1) A. 4 phyla

III. Fungal associationsA. MycorrhizaeB. Lichens

Fungi are our relatives

Common Ancestor

FungiBreathe in….

Armillariella - a fungus found in Michigan

40 acres1500 years old 100 tons

The world’s biggest and oldest organisms?

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General Biology of the Fungi What are fungi?

HeterotrophicEnergy, carbon, nutrients from food

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HeterotrophicAbsorptive nutrition –

Secrete digestive enzymes into environmentAbsorb the products


HeterotrophicAbsorptive nutrition Chitin in cell walls

StructureWho else has chitin?

General Biology of the FungiThey may be eat dead or

living food. Saprobes eat dead stuffCarbon cycle

Infectious parasites• Most AIDS patients die of

fungal infections• Ringworm, athlete’s foot,

• Valley Fever

General Biology of the Fungi Some are even predators!

Nematode Fungi

General Biology of the FungiThe fungal body

• Some fungi are unicellular.

Yeasts

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• Mycelium – the vegetative/feeding body• Hyphae – tubular filaments

Septa –incomplete wallsNo

walls


• Hyphae give them a large surface area–to–volume ratio

Low SA:VolHigh SA:Vol

Good for digesting and absorbing their environment

General Biology- Reproduction

• Fungi reproduce asexually or sexually• Sexually:

Mating types (NOT male and female)–2 or more Genetic types that have to mate with another typeNOT a morphologic distinction (like male/female)

General Biology - Reproduction

Dikaryon – hyphae with 2 genetically different nuclei

• Have a haploid (n) diploid (2n) and dikaryon (n+n)

• The cells fuse, but not the haploid nuclei.

Diversity in the Kingdom Fungi• There are 4 fungal phyla• Sexual reproduction is a distinguishing feature

Diversity in the Fungi: Chytrids • Flagellated spores and gametes• Resemble the ancestral fungi• Aquatic organisms

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Diversity in the Fungi: Zygomycetes

• Hyphae undivided into cells grow around exploring and digesting.

• Dispersal - a stalk with a spore sac.

Diversity in the Fungi: Zygomycetes

• No fruiting body• Mating types grow together,

form a zygosporangium(gamete sac)

• The only diploid cells are the zygotes in the zygosporangium.

• Meiosis spores

Diversity in the Fungi: Ascomycetes

• Hyphae are segmented BUT fluid and even nuclei can move

through separations.• Ascus – reproductive structure.

(contains ascospores)


Some are unicellular (like brewer’s yeast)

Why are the ascomycetes my favorite fungi?

Yeast metabolizes glucose into ethanol and C02.


Filamentous and produce cup shaped fruiting structureswith the asci on them.

Diversity in the Fungi: Basidiomycetes• Hyphae have partitions with small,

distinctive pores.• Basidia - sexual reproductive structure

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Diversity in the Fungi: Basidiomycetes

Reproduction:• Hyphae fuse to form dikaryon. • Basidiocarp = fruiting structure

(mushroom)• Basidia develop on the gills. • Haploid spores are made in the basidia.

Diversity in the Fungi: Imperfect Fungi

How do we classify the 4 phyla?By Sexual Reproduction Methods and Structures

Imperfect fungi – fungi that cannot be classified

• Mutualism

Fungal Associations

relationship where both partners benefit

living together in a prolonged ecological relationship

• Symbiosis

Fungal Associations

Mycorrhizae

associations of fungi with plant roots

Important for plant establishment

Plant gets?Fungus gets?

Lichen

NOT a single organism!

A meshwork of a fungi and a photosynthetic microorganism (green algae or cyanobacteria)

Lichen Anatomy - Figure 31.18

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LichensAre they mutualisms?

When associated, the algal cells:1. Leak more2. Grow slower

Associated Not - Associated

So, is the fungus a parasite?

Review of Fungi

• Sister group to animals• Digest and slurp up food outside their bodies• Unicellular or filaments• Important symbiotic relationships:

Mycorrhizaelichens

Review of Fungi

There are 4 fungal phyla: • Chytrids only fungi with flagella• Zygomycetes Make Zygospores• Ascomycetes Make asci. Cup fungi and

brewer’s yeast• Basidiomycetes Make basidium.

mushrooms

fungi diversity 2005 - university of arizona diversity 2005.pdf · • ascus – reproductive...

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