Fungi Chapter 21

Key Vocabulary Chitin: Hypha: Mycelium: Fruiting Body Sporangium: Sporangiophore:

21-1 The Kingdom Fungi After we discuss this section, you should be able to: Write three characteristics of all fungi Draw and label 3 structures on a fungus Write a description of 2 means of reproduction in fungi

Fungi are eukaryotic heterotrophs that have cell walls made of chitin What are Fungi? Fungi are eukaryotic heterotrophs that have cell walls made of chitin Chitin is a complex carbohydrate also found in the external skeleton of insects

How do fungi get energy? They are heterotrophs; specifically they are decomposers or parasites Fungi do NOT ingest their food. Fungi digest food outside of their bodies and then absorb it Many absorb from decaying matter Others absorb nutrients from the body of a host

TAKE A MOMENT…………… Write three characteristics of all fungi 1)Eukaryotic heterotrophs 2)Cell Wall of Chitin 3)Digest Food outside their cells and absorb it

Structure and Function of Fungi Yeast are unicellular All others are multicellular

Structure and Function Multicellular Composed of thin filaments called hyphae ( one cell thick) Bodies are made of many hypahe tangled together to form a mycellium

Fruiting Body A reproductive structure growing from the mycelium In the soil beneath it http://www.mybitoftheplanet.com/2006/big_pics/october/1010fungus2.html

Fairy Rings http://bugs.bio.usyd.edu.au/Mycology/Feeding/extracellDigestion.shtml Some mycelia can live for many years. Nutrients near the center become depleted, New mushrooms sprout at only the edges.

Check Yourself Draw and label three structures on a typical fungus (mushroom)

Reproduction in Fungi Most fungi reproduce sexually and asexually

Asexual Cells or hyphae break off and grow Some produce spores

Spores: reproductive cells capable of growing into a new organism by mitosis In certain fungi, spores are produced in sporangia. These are found at the tips of specialized hyphae called sporangiosphores

Sexual Reproduction Two different mating types; plus and minus Plus and minus fuse and form a diploid zygote The diploid zygote undergoes meiosis and produces haploid spores that grow into a new fungus

How Fungi Spread Spores scatter easily in the wind Some have smells that attract animals to help in the dispersing The probability that a spore will produce a mature Organism? One in a BILLION!!! The Spore must have a specific temperature, moisture and food

Key Vocabulary Zygospore Rhizoid Stolon Gametangium Conidium Ascus Ascospore Budding Basidium Basidiospore

After discussing 21-1; be able to List the four phyla of fungi and identify two main characteristics of the members of each

21-2 Classification of Fungi Classified according to their structure and method of reproduction There are over 100,000 species!

Phylum Zygomycota Familiar molds that grow on meat, cheese and bread Members have life cycles that contain a zygospore zygospore- is a resting spore that contains zygotes formed during the sexual phase of the mold’s life cycle. Hypha- lack cross walls reproductive cells do contain cross walls http://tolweb.org/Zygomycota

Structure and Function of Molds Best know zygomycetes is the black bread mold (Rhizopus stolonifer) Hypha of black bread mold Rootlike hypha that penetrate the surface are rhizoids Stemlike hypha the run along the surface of the bread are stolons

Life Cycle of Molds

Phylum Ascomycota Over 30,ooo species Sexual and Asexual Reproduction http://www.perspective.com/nature/fungi/ascomycota.html

http://courses. bio. psu. edu/fall2005/biol110/tutorials/tutorial36 http://courses.bio.psu.edu/fall2005/biol110/tutorials/tutorial36.htm http://courses.bio.psu.edu/fall2005/biol110/tutorials/tutorial36.htm

in asexual reproduction tiny spores called conidia-are formed at the tips of specialized hyphae called conidiophores. in sexual reproduction when haploid hyphae of two fungi grow close together and produce fruiting body ascus- forms within the fruiting body. Ascospores- when eight cells are formed after mitosis

Yeasts (Ascomycota) Yeasts-are unicellular fungi ascomycetes- are used by humans for baking and brewing yeast is not dead it contains ascospores they become active when in moisture

Yeast (Ascomycota) yeast reproduces by an asexual process called budding. The genus is saccharomyces meaning sugar fungi are used in baking and brewing the production of carbon dioxide- makes bread rise and beverages bubble in baking the alcohol is evaporated and in brewing it results in alcoholic beverages

Phylum Basidiomycota Common name is club fungi Gets its name from a specialized reproductive structure called a basidium that resembles a club http://www.flickr.com/photos/atlapix/1541962728/

Basidium-the spore bearing structure is found under the gills that grow on the underside of the mushroom caps. Life Cycle of Club Fungi- very complex life cycle

Diversity of Club Fungi orange jelly star Stinkhorn iii.shelf fungi iv.Fly agaric v.bird’s nest fungus Oregon state university

Edible and Inedible Fungi several types of mushrooms have been cultivated for food Wild mushrooms are a different story- many are poisonous never pick mushrooms to eat

Phylum Deuteromycota Is composed of those fungi that are not placed in other phyla because researchers have never been able to observe a sexual phase in their life cycles. Ex. Penicillium that grows on fruit and the source of the antiobiotic.

Review: Zygomycota Basidiomycota Ascomycota Characteristics of Dueteromycota Characteristics of

Key Vocabulary Saprobe Lichen Mycorrhiza

21-3 Ecology of Fungi All fungi are heterotrophs Fungi cannot manufacture their own food They cannot move but their mycelia grow very rapidly Some are parasites, which harm other organisms while living on them d.Some are symbionts-live in mutually beneficial associations e.Many are saprobes- organisms that obtain food from decaying organic matter.

Most feed on decaying matter some catch live animals Pleurotus Ostreatus-is a carnivorous fungus that lives on the side of trees as roundworms crawl into the fungus to feed the hyphae penetrate them and begin digesting them

Fungi as Decomposers They release digestive enzymes that breakdown leaves, fruit, and other organic material into simpler substances Fungi are found in every ecosystem, where they recycle nutrients by breaking down the bodies and wastes of other organisms

Fungi as Parasites Plant Diseases Can infect both animals and plants Mildews are a type of fungi Wheat rust – corn smut – destroys corn kernels a type of basidiomycete- has its spores carried by wind to Wheat which it infects

Animal Disease Human diseases fungal parasites can infect humans deuteromycete affects toes- athlete’s foot the mycelium forms within the outer layers of the skin it also produces “ring worm” which is not a worm at all Candida albicans ; a yeast that can grow In moist areas of the body

Animal Diseases Genus Cordyceps fungus infects grasshoppers in rain forests

Symbiotic Relationships Some fungi form symbiotic relationships in which both partners benefit.

Lichen usually ascomycetes resistant to drought and cold they can grow on rocks are often the first to enter a barren environment live symbiotically between fungi and photosynthetic organism live on green alga or cyanobacterium

Mycorrhizae Mutualistic relationships with plants These relationships are called mycorhizae The tiny hypha help the plant absorb neutrients Often roots are woven into a partnership with fungal mycelia

Mycorrhizae

Answer these: Write a description for two mutualistic relationships that fungi form with other organisms Write a compare and contrast paragraph of corn smut and mycorrhizial fungus on Douglas fir tree Fungi are important to an ecosystem because they ___________________ organic material and put nutrients back in the soil