module 9

• Fungi


  Eukaryotic organisms that may be unicellular (yeast) or multi-cellular (molds, mushrooms)

  
• Fungi


  • Fungal cells are enclosed in cell walls composed of chitin
  • Lack chloroplast and chlorophyl thus are non-photosynthetic
  • Decomposers obtain nutrients from dead organic matter
  • Parasites obtain nutrients from living organisms
  • Grow best in moist areas wherever organic materials are available
  • Produce desiccation-resistant spores (sexually or asexually) to survive dry environment
  • Can tolerate environment with a wide pH (2-9) and temperature range and can thrive through environments with high osmotic pressure
• Phyla of the Kingdom Fungi


  • Zygomycota
  • Ascomycota
  • Basidiomycota
  • Chytridiomycota

  
• Zygomycota


  • Most primitive terrestrial fungi
  • Have thallus of coenocytic hyphae (one long cell that is not divided into compartments) in which nuclei are haploid when the organism is vegetative stage
  • Usually reproduce asexually by producing sporangiospores that can germinate when it reaches an appropriate substrate
  • Stolon that rapidly propagates on the surface of breads, fruits, and vegetable
  • Most are saprobes (live off decaying matter)
  • Some are parasites of plants, insects, and small animals
  • Others form symbiotic relationship with plants

  
• Ascomycota


  • Includes molds that have septate hyphae (divided into compartments) and yeasts
  • Reproduce sexually through ascospores (sexual spores) produced in a sac or ascus; and asexually via conidiospores

  
• Ascomycota


  • yeast
  • molds
  • powdery mildews
  • morels
  • truffles
• Basidiomycota


  • Also possess septate hyphae
  • Reproduce sexually through their basidiospore produced in the basidium (club-shaped structure)
  • Basidia are found along the gills or pores underside the cap of mushrooms
  • Some may produce toxins that are harmful and even lethal to human beings

  
• Basidiomycota


  • mushrooms
  • rusts
  • smuts
  • bracket fungi
  • puffballs

  
• Chytridiomycota


  • May be unicellular or composed of cells forming a thallus (body) which may have slender extensions called rhizoid (anchors to food source)
  • Small simple fungi that inhabit in ponds and damp soil; few species live in salt water
  • Most decomposers that degrade organic materials
  • Only fungi that have flagellated cells
  • Reproduce asexually through their spores with a single posterior flagellum; sexual reproduction has not been observed but some species that reproduce sexually have flagellated gametes

  
• Chytridiomycota


  • Chytridium
• Fungi are used in the production of wine, beer, bread, and distinctive cheese
• Penicillin was the first antibiotic discovered by Alexander Fleming from molds
• Fungi can cause many plant diseases such as Wheat rust, Dutch elm diseases, and Chestnut blight
• Some fungi can also cause diseases in animals and humans such as ringworms, athlete's foot and jock itch
• Lichens


  • Composed of two different organisms: algae and fungi
  • Can potentially grow on any surface (especially rocks) or as an epiphyte
  • Reproduce asexually by fragmentation; some release soredia (special dispersal units) that contains cells of both partners
  • The symbiotic mutual relationship between algae and fungi provides each other benefits; fungi absorbs nutrients from the source while algae and produce food via photosynthesis
  • Lichen grows slowly and may live for centuries in extreme temperature and moisture
  • They have been used in foods and to extract chemicals as dyes or antimicrobial substances
  • Some are very sensitive to pollution (vacuoles cannot store or sequester absorbed elements), especially with sulfur dioxide, and have been used as environmental indicators
  • Lichens have a body called thallus with a cortex (outer, tightly packed fungal layer), medulla (inner loosely packed fungal layer), and rhizines (hyphal bundles attached to the substrate)
• General Growth Forms of Lichens

  • Crustose
  • Foliose
  • Fruticose

  
• Fungi thrive best in warm tropical and subtropical regions


  Lichens flourish in temperate and colder regions

  
• Fungi prefer moist, dark, shady places and vitiated atmosphere of towns


  Lichens prefer to be exposed to air and light and dislike smokey atmosphere
• Fungi requires living or dead organic matter to absorb nutrients and demand much moisture


  Lichens can grow on barren substratum under drought and starvation conditions
• Fungi can grow either a parasite or a saprophyte


  Lichens grow generally as epiphytes or autophytes

  
• Fungi thallus is generally colorless


  Lichens thallus are generally colored due to various acids

  
• Fungi thallus are usually filamentous mycelium, delicate in texture and immersed in substratum


  Lichens thallus is generally tough, leathery in texture and in most lichens are soft as rubber sponge