Classification

• Systematics - is the study of biological diversity which focuses on the evolutionary history of organisms
• Taxonomy - is the science of identifying, naming and classifying organisms based on natural relationship.
• Phylogenetic - is the study of the evolutionary

  relatedness among groups of organisms.
• Classification - is the grouping of living organisms

  according to similar structures and functions.
• Aristotle - A Greek philosopher, proposed a system of classifying living things. He grouped organisms into plants and animals.
• Carolus (Carl) Linnaeus, a Swedish botanist, established this method of animal kingdom classification in the 1700s.
• The Linnaeus System defines a taxonomic hierarchy and binomial nomenclature, which gives each animal species a two-word scientific name.
• The following rules are observed when writing scientific names:

  • The first letter of the genus name is capitalized, but the species name begins with a small letter.
  • If printed in books or magazines, both names are italicized.
  • If handwritten, both names should be underlined.
  • After the scientific name has been written in full, the genus name may be abbreviated to the first letter in the succeeding citation .
• ICN - International Code of Nomenclature algae fungi and plants
• ICZN - International Code of Zoological Nomenclature –Animals
• ICNB - International Code of Nomenclature of Bacteria- Bacteria
• ICNCP- International Code of Nomenclature for Cultivated Plants
• ICTV- International Code on Taxonomy of Viruses (ICTV)
• Taxonomic Hierarchy

  • Kingdoms are divided into groups called phyla
  • Phyla are subdivided into classes
  • Classes are subdivided into orders
  • Orders are subdivided into families
  • Families are divided into genera
  • Genera contain closely related species
  • Species is unique
• ERNEST HAECKEL- Proposed the Third Kingdom, named PROTISTA, to accommodate with the problematic group of Protozoa, Algae, and Bacteria.
• HERBERT COPELAND- in 1938 proposed FOUR KINGDOM SCHEME of biological classification naming Monera the fourth Kingdom to include bacteria and blue-green algae now cyanobacteria.
• ROBERT WHITTAKER- separates nonphotosynthetic fungi in Kingdom Plantae and proposed the FIVE KINGDOM SCHEME which include the KINGDOM FUNGI.
• CARL WOOSE divide the Kingdom Monera into two separate kingdom namely Archaebacteria and Eubacteria.
• Archaebacteria

  • Ancient bacteria
  • Prokaryotes
  • Unicellular
  • Mostly extremophiles
  • Some are autotrophs,
  • some are heterotrophs
• Methanogens –anaerobic/ -produce methane
• Thermophiles thrive in extreme environment
• Halophiles -thrive in salty environment
• Eubacteria – “true” bacteria which include all bacteria that affect man and animals.
• Psychrophilic Organisms - prefer cold temperature between 0 to 20 degrees Celsius
• Mesophilic organisms - prefer temperature between 20 to 40 degrees
• Thermophilic organisms - prefer high temperature (higher than 40 degrees)
• Aerobes - Those growing in the presence of oxygen.
• Facultative Anaerobes - Those grow better in the

  presence of O2 but can also grow in absence of O2.
• Obligatory Aerobes can grow only in the presence of

  oxygen, but cannot grow in its absence.
• Obligatory Anaerobes grow only in absence of O2.
• Micro Aerophillic - grows best in presence of low oxygen tension
• Lactic acid bacteria have been used to ferment or culture foods for at least 4000 years.

  Examples: products like yogurt and cheese
• Wastewater bacteria feed on everything from solid human waste matter. As the bacteria eat, they convert organic matter to carbon dioxide, releasing electrons, the basic element of electrical current.
• Kingdom Plantae

  • Plants are eukaryotic,multicellular and carry out photosynthesis. They are autotrophs.
  • The cell of plants have cell wall,that contain the polysaccharide cellulose.
  • Plant cells are specialized for different functions, such as photosynthesis, the transport of materials, and support.
• Kingdom Protista

  • Mostly aquatic
  • Most are heterotrophic some autotrophic
• There are three phyla of protists, based on their type of nutrition:

  • animal-like
  • plant-like
  • fungi-like
• Protozoa (animal-like protists) are heterotrophs that ingest or absorb their food.
• Classified by how they move:

  1. Pseudopods : (false-feet)
  2. Flagellates : (moves with flagella)
  3. Ciliates : (moves with cilia)
• Algae (plant-like protists) are autotrophs they get nutrition from photosynthesis.

  Classified by their cell wall -

  • Euglenoids
  • Dinoflagellates
• Kingdom Fungi

  • eukaryotic, heterotrophic, and mostly multicellular like bread molds and mushrooms, (yeast unicellular).
  • They possess cell wall usually made of chitin and are spore formers.
  • Obtain the food by absorbing nutrients from organic materials.
  • Decomposer or parasites