Biological classification

• Kingdom Monera

  • Most abundant micro organisms
  • They live in extreme conditions also in or on other organisms as parasites
  • They have 4 shapes namely: Coccus (spherical), Bacillus (rod shaped), Spirilla (spiral shaped), Vibrio (comma shaped)
  • Most bacteria are heterotrophs
• Archaebacteria

  • Special bacteria since they live in extremely harsh conditions
  • 3 types : Halophiles (salty areas), Thermoacidophiles (hot springs), Methanogens (inside animals guts. Help create methane biogas from dung)
• Eubacteria

  True bacteria
• Eubacteria

  • Rigid cell wall
  • If motile, a flagellum
• Cyanobacteria

  Also known as blue green algae, photosynthetic autotrophs
• Cyanobacteria

  • Their colonies are surrounded by a gelatinous sheath
  • They can fix atmospheric nitrogen using cells called heterocysts
• Cyanobacteria

  • Nostoc
  • Anabaena
• Chemosynthetic autotrophic bacteria

  Oxidise various inorganic substances such as nitrates, nitrites, ammonia, use the released energy for ATP production
• Chemosynthetic autotrophic bacteria play a great role in recycling nutrients like nitrogen, iron, Sulphur, phosphorous
• Heterotrophs

  Most abundant type of bacteria, help in making curd, produce antibiotics, fix nitrogen in legume roots
• Some heterotrophic bacteria cause damage to humans, crops, animals, pets
• Well known diseases caused by bacteria

  • Cholera
  • Tetanus
  • Typhoid
  • Citrus canker
• Bacterial reproduction

  1. Fission

  2. Spore production in unfavorable conditions

  3. Primitive type of DNA transfer between bacteria (sexual reproduction)
• Mycoplasma

  Smallest known cell, no cell wall, can survive without oxygen, pathogenic in plants and animals
• Chrysophytes

  • include diatoms and golden algae(desmids)
  • found in marine and fresh water.
  • most are photosynthetic.
  • in diatoms the cell wall forms two thin overlapping shells which fit together like a soap box
  • Cell wall is made up silica making it indestructible
  • form a layer at the bottom called diatomaceous earth
• Dinoflagellates

  • mostly marine and photosynthetic
  • have stiff cellulosic plate on the outer surface.
  • Example is Gonyaulax
• Euglenoids

  • found in fresh stagnant water
  • instead of cell wall they have protein rich layer called pellicle makes them flexible
  • in presence of sunlight are photosynthetic but no sun= heterotrophs
  • 2 flagella one long one short
  • pigment of euglena also found in higher plants
  • eg euglena
• Slime Moulds

  • saprophytic protists
  • they engulf leaves and twigs in their way
  • when suitable create an aggregation called plasmodium
  • when unfavorable create spores which posses true cell wall are extremely resistant and survive for many years
  • spores are distributed by air currents
• Protozoans

  • all are heterotrophs
  • 4 major groups
  • Amoeboid protozoans - live in freshwater capture prey by pseudopodia marine forms have silica shells on their body
  • flagellated protozoans - free living or parasitic have flagella and can cause diseases such as Trypanosoma
  • ciliated protozoans - aquatic have a cavity that opens to outside of cell surface Eg paramoecium
  • sporozoans - includes infectious spores Eg plasmodium(causes malaria)
• kingdom fungi

  • multicellular organisms
  • cell wall- chitin
  • except yeast, bread, beer, saccharomyces cerevisiae
  • habitat cosmopolitan i.e. they live in air, plants, water, animals, land.
  • mode of nutrition- heterotrophs
  • septate- cross walled, uninucleated
  • reproduction:
  • i: vegetative:
  • I: budding
  • II: binary fission
  • III: fragmentation
  • ii: asexual:
  • I: spores
  • a: sporangiospores(endogenous) -> zoospores -> motile & aplanospores -> non-motile
  • b: conidia (exogenous) -> non motile