Classification
The levels of taxonomy are Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.
The classification system according to Linnaeus is best described as ordering organisms by seperating them based on what their structure looks like and falls into the categories; kingdom, phylum, class, order, family, genus, and species.
The classification system according to Aristotle is best described as classifying all organisms as either a plant or an animal. The problem with thhis classification is that there are more than just plants and animals.
Taxonomy is the discipline of classifying organisms and assigning each organism a universally accepted name.
Six Kingdoms
Archaebacteria
Members of this kingdom are unicellular prokaryotes that live in extreme environments like volcanic hot springs, brine pools, and black organic mud totally devoid of mud.
Characteristics
- Cell walls
- Contain fatty acids
- Complex RNA polymerase
- System of matabolism
Eubacteria
Members of this kingdom are unicellular prokaryotes that are ecologiccally diverse, ranging from free-living soil organisms to deadly parasites. Some photosynthesize, while others do not.
Charcteristics
- Prokaryotes
- Cell walls made of peptidoglycan
- Stronger cell walls
- Less complex
Protista
Members of this kingdom cannot be classified as animals, plants, or fungi. They can be unicellular or multicellular, photosynthetic or heterotrophic. Some of these organisms share characteristics with plants, other with fungi, and others with animals.
Characteristics
- Eukaryotic
- Mostly unicellular
- Kelp or seaweed or examples of large multicellular protists
Fungi
Members of this kingdom are heterotrophs. They feed on decaying matter or secrete digestive enzymes into their food source. Some are multicellular while others are unicellular.
Characteristics
- Most grow tubular filaments called hyphae
- Walls of hyphae are usually strengthened with chititn
- Disperse theirselves by releasing spores
Plantae
Members of this kingdom are multicellular. They are photosynthetic autotrophs. These organisms have cell walls made of cellulose.
Characteristics
- Mostly eukaryotic containing chlorophyll
- Most have cell walls
- Have the ability to grow by cell division
Animalia
Members of this kingdom are multicellular and heterotrophs. These organisms DO NOT have cell walls
Characteristics
- Multicellular
- Eukaryotes
- Heterotrophic
- Humans are in this kingdom