Taxonomy

🧬 TAXONOMY & CLASSIFICATION


1. Taxonomy


Taxonomy is the branch of biology that deals with naming, identifying, and classifying organisms.


2. Classification


Classification is the process of grouping organisms based on their similarities and differences.


3. Identification


Identification is the process of determining what organism something is, usually by comparing its characteristics with known organisms.


4. Nomenclature


Nomenclature is the system used to give organisms scientific names.


Binomial nomenclature gives each organism two names:


  • Genus — first and capitalized

  • Species — second and lowercase


Example: Homo sapiens


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🔽 TAXONOMIC HIERARCHY


From highest to lowest:


Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species


🧠 Memory trick:

Dear King Philip Came Over For Good Sex.


  • Domain = broadest group

  • Species = most specific group


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🌎 TWO MAIN DOMAINS


For the two-domain system:


  • 1. Prokaryota


Organisms whose cells do not have a nucleus.


Examples: bacteria and archaea.


  • 2. Eukaryota


Organisms whose cells have a nucleus.


Examples: animals, plants, fungi, and protists.


Some textbooks use a three-domain system instead: Bacteria, Archaea, and Eukarya. Follow whichever system your teacher uses.


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🌱 FIVE KINGDOMS


1. Monera


  • Single-celled

  • Prokaryotic

  • No true nucleus

  • Example: bacteria


2. Protista


  • Mostly single-celled

  • Eukaryotic

  • Can be plant-like or animal-like

  • Examples: amoeba, paramecium


3. Fungi


  • Eukaryotic

  • Usually multicellular

  • Cannot make their own food

  • Absorb nutrients from their surroundings

  • Examples: mushrooms, mould, yeast


4. Plantae


  • Eukaryotic

  • Multicellular

  • Usually make their own food through photosynthesis

  • Examples: trees, grass, flowers


5. Animalia


  • Eukaryotic

  • Multicellular

  • Cannot make their own food

  • Usually capable of movement

  • Examples: humans, insects, fish


  • Animalia :multicellular organisms that eat other organisms (heterotrophic) and usually move   

  • Plantae : Multicellular organisms that make their own food through photosynthesis

  • Fungi:Multicellular organisms unicellular organisms that absorb nutrients from decomposing matter (like yeast and mushrooms)

  • Protista :mostly single celled eukaryotic organisms such as algae and amoebaees

  • Monera:simple single celled prokaryotic organisms that lack a true nucleus such as bacteria