Biology Chapter 24

“Fungi”___________________Biology

24th Chapter

Characteristics of Fungi • Eukaryotic heterotrophs • Most are multicellular (unicellular form is called a yeast) • Are saprotrophic or have a symbiotic relationship Structure of a multicellular fungus • fruiting body – mass of tightly aligned hyphae (usually above ground) • mycelium – mass of densely branched hyphae (usually underground) • hyphae – septate or nonseptate Fungi are classified into phyla based on sexual spores and fruiting bodies A. Flagellated Fungi * Microscopic; primarily aquatic * produce enzymes that degrade cellulose, chitin and keratin * most reproduce by forming zoospores (motile spores with a single flagellum) B. Bread Mold Fungi * mostly terrestrial C. Sac Fungi * unicellular D. Club Fungi * mostly terrestrial E. Interspecies interactions Many fungi interact with other organisms 1. Mychrrhizae (fungus roots) A mutualistic relationship between fungi and plant roots *plant obtains water from water and minerals from fungus *fungus obtains carbohydrates from plant 2. Lichens A mutualistic relationship between fungi and cyanobacteria or green algae • •

algae/cyanobactiera obtain minerals and water from fungus fungus obtains carbohydrates from algae/cyanobactiera

Lichens survive in habitats that are inhospitable to either organism alone, and cannot withstand air pollution. They are sometimes used to monitor air quality.