Biological Classification
🌱 Biology: Biological Classification
Why classify?
To relate & understand between many through DNA, cell, biomolecules, structural similarities.
Taxonomy → a classification program.
Classification
Puts organisms into groups (cladogram = tree).
Classification lists → lists organisms in group based on traits (characteristics).
Binomial Nomenclature → (scientific naming system).
Taxonomy → study of classifying (how we group, based on traits, judging structures).
Phylogeny → study of traits through evolutionary history.
🔹 Groups: Largest to Smallest
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
👉 General to specific → to specific to general
🔹 3 Domains = based on cell type
Archaea
Bacteria
Eukarya
🔹 6 Kingdoms
Archaebacteria
unicellular prokaryote
auto/heterotroph
extreme environments
Eubacteria
unicellular prokaryote
auto/heterotroph
everywhere
Protista
unicellular eukaryote
auto/heterotroph
Fungi
multicellular eukaryote (mushrooms)
heterotroph (absorbs nutrients)
Plantae
multicellular eukaryote
autotroph (photosynthesis)
Animalia
multicellular eukaryote
heterotroph (ingest nutrients)
🔹 Final 7 Levels (Example: Humans)
Kingdom: Eukaryota – (Eukaryote cell)
Phylum: Animalia – (Animal cells, heterotroph)
Class: Mammalia – (All mammals)
Order: Primates – (All primates)
Family: Hominidae – (Bipedal primates)
Genus: Homo – (Humans + Neanderthals)
Species: Homo sapiens – (Humans only)
🔹 Species
Smaller, most specific, most fertile.
Same species → reproduce.
🔹 Binomial Nomenclature
(Bi = two, Nomial = name).
Last two classification groups (genus + species) are used to create unique name for each species.
Ex: Ursus arctos (Grizzly Bear) + Ursus maritimus (Polar Bear).
Latin is used = dead language.
Genus is capitalized, species is not; both are italicized.