Chapter 21- Fungi

Edible morels from Phylum Basidiomycota

Kingdom Fungi• eukaryotic

21-1

•most = sexual/ asexual rep.

•classified by rep. structures

•mostly multicellular; some unicellular (yeasts: most primitive form of fungi)

•cell walls = CHITIN•external, absorptive heterotrophs-release enzymes and break down food externally, then absorb nutrients

Structures: •hyphae- subunits of multicellular fungi, cross walls or no cross walls

•Mycelium- mass of hyphae; nutrient absorption; contain fruiting body (rep. structure ex: mushroom)

4 major groups: * “common molds”* sac fungi* club fungi* imperfect fungi

•Sporangia- produce spores; found at the tips of specialized hyphae called sporangiophores

•Spores- dispersed by wind or animals; germinate in favorable conditions

21-1

Fairy Ring

A. Life cycle includes zygospores-spore that contains zygotes

I. Common molds- Zygomycota

B. Rhizoids-root-like hyphae; grow down

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Fertilization

Meiosis

Asexual Reproduction

Sexual reproduction

Black Bread Mold- Rhizopus stolonifer

C. Stolons-hyphae that runs along surface; will form sporangiophores with sporangia

II. Sac-fungi-Ascomycota A. ascus- sexual rep.structure that contains ascospores

B. conidia- asexual spores

C. yeasts- unicellular; oldest and most primitive fungi; sexual (ascospores) or budding (asexual)

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Figure 21–6 These cup fungiare members of the phylumAscomycota. In cup fungi, asci lie on the interior surface of the cup. At maturity, the spore-filled asci burst, releasing the spores into the air.

III. Club-fungi-Basidiomycota

A. Basidium- club-shaped rep. structure; found in the gills that grow on the underside of cap

B. Most complex life cycle of all fungi

C. Ex: Puffball, Stinkhorn, Shelf Fungi, Bird’s Nest Fungus; Jelly Fungi; Mushroom

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Orange JellyPigskin Poison Puffball

Fly Agaric

Star Stinkhorn FungiShelf Fungus Bird’s Nest Fungus

IV. Deuteromycota- Imperfect Fungi

A. No known mode of sexual rep.

B. Most closely resemble ascomycetes (sac-fungi)

C. Best known:Penicillium; fruit mold/ antibiotics

21-2

Penicillium Conidiophores - Orange Peel

Penicillium notatum (Produces Penicillin)

V. Ecology of Fungi 21-3

A. Saprobes (organisms that obtain food from decaying organic matter) and parasites

B. Decomposers- recycle nutrients in ecosystems

C. Parasites

1. plants-corn smut, fruit mildews; wheat rust; 15-50% crops lost to fungi from temperate to tropical zones

2. Animals- athlete’s foot/ ringworm (deuteromycete); yeast infections/ thrush (yeast-ascomycete);

21-3D.Symbiotic Relationships

1. Lichens- mutualism between fungi/ algae or fungi/ cyanobacteriai. fungi= provides minerals/ SA for water absorption; protection for algae; algae or cyanobacteria = make sugar via photosynthesis

ii. drought/ cold resistant = pioneer species

iii. Indicators of air quality- sensitive to air pollution

2. Mycorrizhae-means ”fungal root”; mutualism b/t fungi/ plant roots

21-3

i. 80% of plant species have mycorrizhae

ii. Fungi- increase surface area for water/ mineral absorption; plant roots= offer fungi sugars from photosynthesis.

Basidiomycete with a conifer.

Basidiomycete w/ angiosperm

Mycorrizhae

21-1

The cell walls of fungi are made up of A. chitin.B. hyphae.C. mycelium.D. cellulose.

21-1The part of the mushroom that appears

above ground is theA. mycelium, or main body of the fungus.

B. photosynthetic organ of the fungus. C. reproductive structure of the fungus.D. structure used to capture prey.

21-1The hyphae that make up multicellular fungi

areA. long chains that are several cells thick.

B. thin filaments that are sometimes divided into cells.

C. the fruiting bodies used in reproduction.

D. the structures that grow above ground.

21-1

Most fungi reproduce A. sexually.B. asexually.C. both sexually and asexually.D. neither sexually or asexually.

21-1

Sporangia are found at the tips of specialized hyphae called

A. gametangia.

B. mycelia.

C. sporangiophores.

D. sporophytes.

21-2

Fungi grow best in an environment that is A. cool.B. moist.C. dry.D. salty.

21-2

Yeasts are

A. zygomycetes.

B. ascomycetes.

C. basidiomycetes.

D. deuteromycetes.

21-2

Penicillium is a(an)

A. ascomycete.

B. basidiomycete.

C. deuteromycete.

D. zygomycete.

21-2

Sac fungi have a characteristic reproductive structure called a(an)

A. ascus.B. basidium.C. budding capsule.D. sporophyte.

21-2

The basidiospores of club fungi are produced on thin structures called

A. fruiting bodies.B. buttons.C. gills.D. stalks.

21-3Which of the following is NOT true of fungi?A. Some of them perform valuable service as

decomposers.B. Some of them have a beneficial

association with plants.C. Some of them can make their own food.

D. Some of them cause serious diseases of plants, animals, and humans.

21-3

Ringworm is caused by a

A.worm.

B. fungus.

C. plant.

D. protist.

21-3Research on mycorrhizae shows that plants

A. are not dependent on other organisms.

B. are closely related to fungi.

C. may depend on other organisms.

D.are seriously damaged by fungi.

21-3

In a mutualistic relationship A. both partners benefit.B. one partner benefits.C. neither partner benefits.D. neither partners is affected by the other.

21-3Lichens are symbiotic associations

that might be formed between

A. a fungus and an animal.

B. a plant and a bacterium.

C. a cyanobacterium and a plant.

D. a fungus and an alga.