Fungi essays

Fungi essays What are the fungi? Mushrooms, molds, yeasts, athlete's foot diseases, rusts, and smuts All are filamentous or unicellular. Individual filaments are termed hyphae. A mass of hyphae is the mycelium (the feeding stage) Walls of the filaments are of cellulose with chitin Cells are eucaryotic; that is, they contain nuclei, mitochondria, other organelles Nutritionally, all fungi are heterotrophic, mostly aerobic Saprophyticlive off dead organic matter Parasiticobtain nutrients by penetrating tiny branches (haustoria) into a host Sexualgametangia produce sperms and eggs Decomposers of organic materialsimportant recyclers of matter The representative genus I shall use is Saprolegnia (can be collected from freshwater habitats by using apple baits in wire cage) A true mycelium, of tubular threads The hyphae have 2N nuclei (numerous) Mycelium grows and sooner or later reproduces Zoospores are released, attach to a food particle, germinate to become hyphae, then mycelium The same mycelium that produced the sporangia now forms the sex organs Antheridia> sperms (gametes) Gamete fusion occurs in the oogonium Zygotes are released, germinate, attach to a food mass. Mycelium feeds, grows, eventually reproduces See page 532 in your text for the life cycle. ...