Diversity of Living Things

3.1: Fungi

Plants & Fungi

• Fungi have many similarities to plants, but the differences distinguish fungi as a separate kingdom

• Similarities with plants:– eukaryotic cells with organelles and cell walls– most do not move and grow in soil or other surface– reproduction sexual, asexual, or both

Fungi & Plants

• Differences from plants:– can have many nuclei in cells (plants only one

nucleus per cell)– are heterotrophs (plants are mostly

autotrophs)– have few storage molecules (plants have

starch to store carbohydrates)

Fungi & Plants

• Differences from plants (cont’d):– have no roots (plants have roots)– have chitin in cell walls (plants have cellulose

in cell walls)– do not reproduce by seed (some plants

reproduce by seed)

Importance of fungi

• Major decomposer: cycling of nutrients• Symbiotic relationships with plants: fungi help

plants attain nutrients from soil, plants give fungi food from photosynthesis

http://www.livescience.com/php/multimedia/imagedisplay/img_display.php?pic=060410_ground_fungi_02.jpg&cap=Fungi+decomposing+a+fallen+log+in+the+Amazonian+rainforest+of+Peru.+Credit%3A+Steven+Allison

Importance of fungi cont’d

• Cause diseases in animals and plants• Source of consumer products: mushrooms,

truffles; help to make bread, soy sauce, blue cheese and alcohol; source of antibiotic penicillin; used in genetic engineering

http://www.bigoven.com/glossary/Blue%20Cheese

http://www.myhomecooking.net/bread-recipes/wheat-bread-recipe.htm

http://qtips4you.blogspot.com/2010/10/bogo-kikkoman-and-other-coupons.html

Classification and Phylogeny• More than 100 000 species of

fungi have been identified• There are 5 major phyla

including Basidiomycota (mushrooms) and Zygomycota (moulds on food)

• Phyla range in size from microscopic to largest on Earth (Armillaria ostoyae) is 2, 384 acres long which is equivalent to 1, 665 football fields!)

• See Table 1 on p. 81 http://thedarksideoftheshroom.blogspot.com/2010_04_01_archive.html

Characteristics• Display extreme diversity in

terms of life cycle and characteristics

• Body of fungi is composed of network of branching filaments called mycelium. The filaments are called a hyphae (sing. hypha)

• Each hypha contains many nuclei and has cell wall containing chitin

• Tubes may be separated by cell wall called septa

http://www.fungionline.org.uk/3hyphae/1hypha_ultra.html

http://sites.google.com/site/rccbiology/home/chapter-21-fungi

Characteristics cont’d

• Most fungi are multicelluar but some can be unicellular. Yeast is a unicellular fungi which is involved in bread and alcohol production

• All fungi are heterotrophs (saprophytes or parasites)

http://www.pmbio.icbm.de/mikrobiologischer-garten/eng/enhef01.htm

Video clip on Fungi

• http://www.youtube.com/watch?v=5_rprVa-RY4&feature=fvwrel

Characteristics cont’d

• Fungi use external digestion (digest then ingest)– They grow next to or within food source and

release enzymes which break down food so that nutrients can be absorbed across hypha

– Distribution of absorbed nutrients occurs through the mycelium

– Most fungi store their food as glycogen (like animals)

Symbiotic Relationships in Ecosystems

• Lichens are symbiotic combinations of sac fungi and cyanobacteria or green algae– Fungi supply materials for photosynthesis and

plants return favour by providing food to fungi

http://www.sheridanmedia.com/news/community-colleges-quotpartnershipsquot-and-lichens13308

Other symbiotic relationships

• Many examples between animals and fungi– Leaf-cutter ants and fungi

http://ecolibrary.org/page/DP176

Mycorrhizae

• Mycorrhizae involves more than 80% of all plants– Hyphae grow around plant’s root cells. Fungi give

plant nutrients like phosphorous and plant provides fungi with food

http://www.apsnet.org/edcenter/illglossary/Pages/I-M.aspx

Decomposers and disease

• Fungal diseases are called mycoses• Some diseases caused by fungi are mild like

athlete’s foot and ringworm infection • Some cause respiratory diseases such as

Aspergillosis in humans like Blastomycosis and Cryptococcosis

http://health.allrefer.com/health/cryptococcosis-cryptococcosis-on-the-forehead.html

http://littletvaddict.com/2010/05/otc-treatment-for-atheletes-foot-for-someone-on-warfarin/

Video of disease-causing fungi: Cordyceps

• http://www.youtube.com/watch?v=CCOQ0VU24xw