Transcript Chapter 24
Chapter 24 Kingdom Fungi Characteristics of Kingdom Fungi Heterotrophic Store food as glycogen instead of starch Most are saprobes- fungi that feed on organic wastes and remains. Some are parasites Characteristics of Kingdom Fungi Have cell walls. Walls made of chitin (like insects) instead of cellulose (like plants and protists) Fungi are classified based on types of structures produced during sexual reproduction. Largest groups: zygomycetes, basidiomycetes, and ascomycetes Extracellular Digestion Fungi digest tissues by secreting digestive enzymes onto the tissue. Then they absorb the digested product. This is beneficial to plants and the fungi Mycelium- net of filaments (filament= hyphae). Provides high surface area to volume ratio for absorbing nutrients. Zygomycetes Terrestrial and mostly saprotrophs. Some parasites Highlighted genus: Rhizopus R. stolonifer- black bread mold Zygospores (2n) produce reproductive spores (n) Basidiomycetes- Club Fungi Grocery store mushrooms Spores form in basidia- club shaped structures that form from mycelia Basidia (n+n) produce zygotes Ascomycetes- Sac Fungi Spores form in sac-shaped asci cells. Baking yeast Aspergillus (citric acid), Penicillium (cheese and antibiotics), food spoiling fungi Largest group The Unloved Species READ SECTION 24.5 on pg. 397 Be familiar with some common harmful fungal species. The Symbionts Endophytic fungi live inside plants. The symbiotic relationship between fungus and plant results in benefits for both species. Lichens and fungus-roots Lichens Symbiotic relationship between a photosynthetic species and a fungus. Photobiont- photosynthetic portion (ex: cyanobacteria) Mycobiont- fungal portion- largest component Live in places too hostile for other speciesfrozen rocks, “Old Man’s Beard”- an indicator of air pollution Fungus-roots Soil fungi that are mutualists with young tree roots. “Micorrhiza”- the symbiotic network of roots+ fungus Increases the absorptive surface area. Plant gives up some sugars. Fungus gives up absorbed nutrients. Mycorrhizae Increases the absorptive surface area. Plant gives up some sugars. Fungus gives up absorbed nutrients.