Chapter 20.1Diversity of Fungi

FUNGI

FUNGI

• COMMON FUNGI EXAMPLES:– Mushrooms, yeasts,

molds, morels, bracket fungi, puff balls

Key Concepts:

• Fungi are heterotrophs

• Fungi are the decomposers

• Fungi use extracellular digestion – when enzymes are secreted outside of their body to digest food

• Most fungi are multicellular

• Fungal spores develop from hyphae

• Many fungi are symbionts with other organisms

Characteristics of Fungi

• Multicellular– Plant looking– Mushrooms, molds

• Single cell– Yeasts– Found in soil, on plants,

in humans– Bread, beer, wine– Cause yeast infections in humans

Yeast

3 Major Features1.Cell walls

– Made of Chitin– The same stuff that makes insects’

exoskeleton.

2. Hyphae

• The basic structure of fungi.• Long, thread-like chains of cells.• Grow at the tips and branch…• Mycelium – mass of hyphae

3. Cross-walls

• The wall that divides cells• “septum”

FUNGI

• FRUITING BODY– Visible part– Contains spore producing structures– Like a mushroom cap

Button

Fungi Nutrition• 3 ways fungi absorb nutrition:

– Saprophytic – feed on dead matter• Example – bracket fungi

– Parasitic - feed on living organisms and only the parasite benefits from the relationship

• Example - ringworm

– Mutualistic – both organisms benefit from the relationship

• Example - mycorrhizae

Fungi Reproduction

• 3 kinds of fungi reproduction:– Budding

– Fragmentation

– Spore production

Sporophores

• The fruiting body of a spore forming fungus

Bread Mold

Sporangium

• The sac where spores are produced• Protects spores from drying out

Chapter 20.2Fungi Phyla

5 Phyla of Fungi

1. Chytridiomycota - Chytrids

2. Zygomycota – Common Molds

3. Ascomycota – Sac Fungi

4. Basidiomycota – Club Fungi

5. Deuteromycota – Imperfect Fungi

SULFUR SHELF FUNGUS Polyporus

BIG LAUGHING MUSHROOM Gymnophilus

PURPLE CORAL FUNGUS Clavaria RUBBER CUP FUNGUS Sarcosorna

TRUMPET CHANTARELLE Caraterellus

SCARLET HOOD Hygrophorus

The light red coral Fungus, Ramaria

The shelf Fungus, Polyporus

Fly Agaric mushroom, Amanita muscariaCauses hallucinations when eaten.

A.ocreataVery poisonous

1. Phylum Chytridiomycota

Mostly marine. Mostly saprophytes.Have flagellated spores.

2. Phylum ZygomycotaMostly terrestrial.Two types of hyphae:

Stolons – spread across the surface

Rhizoids – digs into the surface

nuclear fusion meiosis

zygospore (2n)

spores (n) Zygospore Spore sac

mycelium develops from

germinated spore

rhizoids

stolon

ASEXUAL REPRODUCTION

(mitosis)

contact between hyphae of two mating

strains

germinating zygospore

Diploid Stage

Haploid Stage

young zygospore

gametangia fusing

50 µm

spores (n)

molds

3. Phylum Ascomycota

ascospore (sexual spore)

Most are multicellular except for yeast.

Most undergo asexual reproduction.

Sac Fungi

ascospore (sexual spore)

spore sac

spore-bearing hypha of this

ascoscarp

ascoscarp ascoscarp

conidia (chains of asexual spores)

budding yeast cell

Morels

yeasts

4. Phylum Basidiomycota

Major decomposers of wood.Mostly sexual reproduction.

Club Fungi

mushrooms

GIANT PUFFBALL

Humongous Fungus (Honey Mushroom)

5. Phylum Deuteromycota

Ringworm

•Asexual Reproduction (sexual reproduction has never been seen)

•Imperfect Fungi

Chapter 20.3Ecology of Fungi

Mutualistic Fungi

• Some Fungi form Mutualistic relationships with other organisms:– Lichen– Mycorrhizae

H

i

Lichens

BioindicatorsPioneer species

Fungi (usually ascomycota) + algae (or photosynthetic bacteria)

foliose

crustose

dispersal fragment (cells of mycobiont and of

photobiont)

cortex (outer layer of

mycobiont)photobionts

medulla (inner layer of loosley woven hyphae)

cortex

Crustose

Leaf-like - foliose

Old Man’s Beard

Usnea – fructicose

Erect branching Lichen

Cladonia rangiferinafructicose

Crustose

foliose

fructicose

Mycorrhizae

•Fungi + plant roots

• Increases surface area

Fungi

• Molds

– Penicillium• Penicillin

• Camembert and Roquefort cheeses

– Aspergillus• Soy sauce

• Soft drinks - citric acid

• Yeasts

– Saccharomyces cerevisiae

• Bread, wine and beer

– Candida albicans• Infections

Fungi and Humans

• Medical uses:– Penicillin

Penicillin

Fungi and Humans

• Food:– Morels, truffels, yeast

Morel

Truffel

Fungi and Humans

• Bioremediation – clean the environment.

Fungi and Humans• Harmful Fungi:

Some Pathogenic and Toxic Fungi

ZygomycetesRhizopus - Food spoilage

AscomycetesAjeliomyces capsulatus- Histoplasmosis

Aspergillus – sinus, ear, lung infection

Microsporium sp. Various ringworms.

Verticillium sp Plant wilt

Monilinia fructicola-

Brown Rot of Peaches

Basidiomycetes

Puccinia graminis Wheat Rust

Ustilago maydis Corn Smut