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Fungi

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Introduction

• High points - fermented beverages, leaven bread

• Low points - athletes foot, jock itch, that pink stuff that grows on your shower curtain

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Shared Characteristics• Distinctive fungal features

– Fungi are heterotrophs.– Fungi have several cell types.– Fungi have cell walls that include chitin.

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The Body of a Fungus• Fungi exist mainly in the

form of slender filaments (hyphae).

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The Body of a Fungus

• Fungi cell walls are formed of polysaccharides and chitin.

– not cellulose like those of plants

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How Fungi Reproduce

• Fungi are capable of both sexual and asexual reproduction.

– Fungi reproduce sexually after two hyphae of opposite mating type fuse.

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How Fungi Reproduce

• Spores most common means of reproduction

– may form from asexual or sexual processes

– most often dispersed by wind but some spread by insects or other small animals

http://www.youtube.com/watch?v=qDwgSWDqKoQ

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How Fungi Obtain Nutrients

• All fungi obtain food by secreting digestive enzymes and then absorbing the organic molecules produced (external digestion).

– extensive hyphae network provides enormous surface area for absorption

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Four Major Groups of Fungi

• Five groups– Chytridiomycota– Zygomycota– Basidiomycota– Ascomycota– Deuteromycota

Means “second-

fungi. Actually an

Artificial grouping “Imperfect” fungi-penicillin, athlete’s foot

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Chytridiomycota

• aquatic, flagellated fungi (only fungus to have flagella)

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Zygomycota

• includes common bread molds• Life cycle includes a zygospore (contains

zygotes formed during sexual phase of mold’s life cycle)

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Basidiomycota (club fungi)

• Most familiar fungi (mushrooms, toadstools, puffballs, rusts, and smuts)

• Basidia are found on the underside of the mushroom cap

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Ascomycota (Sac Fungi)

• Very large group including yeasts and cup fungi

• Named for the ascus, reproductive structure that contains spores

• Life cycle includes both sexual and asexual reproduction-during asexual reproduction the spores are called conidia

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Ecology of Fungi

• Fungi and bacteria are the principal decomposers in the biosphere.

• Fungi often act as disease-causing organisms for both plants and animals.

– agricultural damage– human health

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Ecology of Fungi

• Mutualistic associations– lichens - fungi and green algae/ plants– mycorrhizae - fungi and plant roots

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Lichens

• Lichens are symbiotic associations between a fungus and a photosynthetic partner.

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Mycorrhizae

• Roots of about 90% of all kinds of vascular plants are involved in mutualistic symbiotic relationships (mycorrhizae).

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Mutualistic Animal Symbioses

• A range of mutualistic fungal-animal symbioses has been identified.

– Ruminants – fungi in gut – release enzymes

– leaf-cutter ants – fungal gardens

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Fungal Parasites and Pathogens

•http://dermatology.fromyourdoctor.com/pennsylvania/northern_cambria/ncmcascp/health/topic.do%3Bjsessionid=91424179D20C68170267C22C5B891CF7?title=Fungal+Skin+Infections+tinea+ringworm&t=2199

•http://www.nature.com/eye/journal/v17/n8/fig_tab/6700557f2.html

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Fungi in History- Ergot Poisoning

The Salem Witch Trials• Toxicologists now know that eating ergot-contaminated

food can lead to a convulsive disorder characterized by violent muscle spasms, vomiting, delusions, hallucinations, crawling sensations on the skin, and a host of other symptoms — all of which, are present in the records of the

Salem witchcraft trials

http://www.wtps.org/wths/imc/Teacher_Assignment/english/Thomas%20the%20salem%20witchtrials.htm

21http://www.flickr.com/photos/gdraskoy/1096292603/

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References

• Information• Miller, . (2005). Biology. Upper Sadle River, NJ: Prentice Hall. • Star, , & Taggert, . (2004). The Unity and diversity of life. US: Thomson.

• Images• http://www.bbc.co.uk/oxford/pictures/visions_science/pop_up_01.shtml• http://chicagoist.com/2006/05/24/beer_hall_homes.php• http://localcrank.wordpress.com/2009/07/07/today-in-history-15/• http://www.rayoverde.org/• http://researchstories.asu.edu/2007/10/the_art_of_life.html• http://faculty.southwest.tn.edu/rburkett/classification_of_organisms.htm• http://www.nmnh.si.edu/rtp/students/2007/

schedule07_entomology_tour_photo1.html