KINGDOM: FUNGI

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KINGDOM: FUNGI

Kingdom fungi mostly have multicellular eukaryotic organisms such as mushroom and mould. Some are unicellular like yeast.Other examples include toad stool, smuts, penicilium, mucor (grows on soil and dead plants), Rhizopus (common bread mould).Rhizopus is saprophytic fungus which grows on decaying food like bread and fruits.

General characteristics

  • Are multicellular except a few e.g. yeast.
  • Fungi inhabit damp or aquatic plants
  • They reproduce by means of spores. They have saprophytic or parasitic mode of nutrition.
  • Have vegetative body called mycelium which consists of a network of hyphae.
  • They have cell walls which consist of a material called chitin.
  • They lack chlorophyll though majority are plant-like

Diagram of common bread mould (Rhizopus)

riplus

Structure of a mush room

mush room

Sexual reproduction

  • Sexual reproduction involves the fusion of the male and female gametes to form a zygote.
  • During sexual reproduction, the two different hyphae face each other and become swollen. The nuclei from each tip develop.
  • The tips meet and form a cross wall.
  • The cross wall breaks and nuclei from different tips pair and fuse.
  • A zygote is formed which develops a thick wall to form a zygospore.
  • The zygospore remains dormant under unfavorable conditions and germinates into a new mycelium in favorable conditions.
illustra

Economic importance of fungi

  • Fungi decay dead organic materials to release materials needed by green plants
  • Yeast respiring anaerobically, provides alcohol for brewers and wine makers.
  • Yeast cells are a source for vitamin B extract
  • Fungi produce antibiotics e.g. penicillum.
  • Fungi provide food e.g. mushroom also used in making cheese.
  • Fungi can spoil food e.g. Rhizopus and penicillum on the bread, cakes, fruits and jam.
  • Fungi causes plant disease e.g. rust, white bright and smut.
  • Dry rot fungus attacks the timber of houses.
  • Fungi causes diseases to man e.g. ringworm, athlete’s foot.
  • Fungi can be used by military to prepare biological weapons to be used in the war fare