biology 2201 ch 5.3 notes.notebook

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Biology 2201 Unit 2 Chapter 55.3 – Kingdom Fungi (pp. 152-159)

Jun 22­7:08 PM

Kingdom Fungi – general characterisitcs

All eukaryotic Most fungi are multicellular, but some are unicellular (ex. Yeast) Bodies are made of fine filaments called hyphae. A loose branching network of hyphae is called a mycelium, and this makes up the bulk of the fungi Some hyphae have cross walls called septa; others do not Have cell walls made of chitin (a hard material found in exoskeletons of insects) Feed on dead and waste matter (saprobes); some are parasitic, some are mutualistic Fungi feed by releasing digestive enzymes outside their bodies to break down food. This is called extracellular digestion.

biology 2201 ch 5.3 notes.notebook

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Fungi - RelationshipsParasitic fungi feed on living cells and can cause things like Athlete’s Foot and Dutch elm disease. Mutualistic fungi help out other species and receive a benefit as well, such as fungi which live in close association with some plants. Mycorrhiza: symbiotic relationship that is mutually beneficial between fungi and roots of plants. The fungal hyphae benefit the plant by absorbing minerals from the soil and releasing them into the roots while the fungus benefits by absorbing organic nutrients from the roots.

Jun 22­7:08 PM

Reproduction in Fungi

- can be asexual, sexual, or both depending on the phylum of fungi - simplest method of asexual reproduction is fragmentation where a piece of a fungus breaks off and forms a new mycelium - Most fungi reproduce by using spores, either produced asexually or sexually. This is an adaptation for living on land. Spores can be carried by the wind, and some can be carried by insects, birds, and other animals - fungi are grouped based on how they reproduce

biology 2201 ch 5.3 notes.notebook

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Groups of Fungi - in the past, fungi were group with the plant kingdom- there are 4 subgroups of fungi 1. Zygospore Fungi (Phylum Zygomycota) 2. Club Fungi (Phylum Basidiomycota) 3. Sac Fungi (Phylum Ascomycota)

4. Imperfect Fungi (Phylum Deuteromycota)

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Zygospore Fungi (Phylum Zygomycota)

Includes bread mould and other decomposers; some parasites → Life cycle of a black bread mould (see fig 5.28, p. 154) • mostly asexual reproduction by spores, but sexual reproduction is used in times of harsh conditions • stolons – horizontal hyphae that are present in the mycelium of a bread mould • rhizoids – in fungi, downward growing hyphae present in the mycelium of a bread mould which penetrate the bread and anchor the mycelium. They help in digestion as well. • Sporangiophores – form of hyphae that project up above the mycelium of a bread mould. Used during asexual reproduction • Sporangium – spore­producing structure in fungi (asexual spores)

biology 2201 ch 5.3 notes.notebook

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October 08, 2011

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Zygospore Fungi (Phylum Zygomycota) cont...

Sexual reproduction occurs when hyphae of opposite strains (called + and – mating strains) combine and their nuclei fuse. This forms a zygospore. → Zygospores form a thick wall around themselves which protects it, and the zygospore does not hatch or germinate until conditions are favourable.

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Zygospore Fungi – bread mould

biology 2201 ch 5.3 notes.notebook

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October 08, 2011

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Club Fungi (Phylum Basidiomycota) Includes mushrooms, puffballs, smuts, rusts, and so on. Largest part of club fungi organism is actually underground, not on the surface. There is a vast, branching network of hyphae underground. The part above ground is the reproductive structure. Most types of club fungi reproduce sexually; some reproduce asexually by conidia • Conidia – type of asexual spores that produce mycelia in Basidiomycotes, Ascomycotes, and Deuteromycotes

Jun 22­7:08 PM

Club Fungi (Phylum Basidiomycota) cont... with sexual reproduction, there are several important terms: Basidocarp – short-lived reproductive structure in club fungi; also called fruiting bodies Basidia – club-shaped hyphae found in club fungi Basidiospores – sexual spores that are borne on club-

shaped hyphae found in members of the Basidiomycotes.

biology 2201 ch 5.3 notes.notebook

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Basidiomycota - mushroom

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Sac Fungi (Phylum Ascomycota)

Includes morels, truffles, and yeast Some saprobes; some parasitic Usual method of reproduction is asexual by conidia, some sexual Asci – small-fingerlike sac structures in which Ascomycotes develop spores (sexual) Yeasts produce asexually by budding (see fig. 5.30, p. 157)

biology 2201 ch 5.3 notes.notebook

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October 08, 2011

Jun 22­7:08 PM

Ascomycota - morels

Jun 22­7:08 PM

Imperfect Fungi (Phylum Deuteromycota)

Only reproduce asexually Develop asexually spores via conidia Includes Penicillium (grows on oranges, makes penicillin); others help in cheese production (blue streaks in some cheeses are streaks of conidia from this group)