TAXONOMY- the branch of biology the deals with naming & classifying organisms. The basis of biological classification is physical structure, although other criteria, such as embryonic, genetic and chemical similarities, are also used.
Scheme of Classification
-taxonomists use several categories in the classification system ranging from
CAROLOLUS LINNAEUS- "Father of Modern Taxonomy"
Linnaeus published his system of taxonomy in a book entitled Systema Naturae (Classification of Nature). Originally published in 1737, it went through 10 editions by 1758. His classification system allowed for the addition of new species. Also, because Linnaeus used structural characteristics, his classification system was easily adapted to the modern system of classification based on evolutionary relationships.
NOMENCLATURE- to keep track of the more than one million different species that have been discovered and classified, a system of naming was formed
BINOMIAL NOMENCLATURE- Linnaeus devised this 2 word naming system. The 2 names used are the genus name (always capitalized) and the species name (always written in lower case). The language used in the system of binomial nomenclature is Latin.
EXAMPLE:
Latin Translation Common Name Genus: Homo Human Species: sapiens wise = Human being
MODERN TAXONOMY
"The rules governing the naming of organisms are provided in three publications: the International Code of Botanical Nomenclature, the International Rules of Zoological Nomenclature, and the International Bacteriological Code of Nomenclature."
SPECIES- a natural group or 'population' that can interbreed and produce fertile offspring
How many species of insects are there?
Estimates of the number of recognized insect species range from about 750,000 to upward of one million-but it is thought by some experts that this represents less than half of the number that exists in the world. About 7,000 new insect species are described each year, but unknown numbers are lost annually from the destruction of their habitats, mainly tropical forests.
PHYLOGENY- is the evolutionary history of a species or group of organisms. A phylogenetic tree indicates when related groups of organisms have evolved from common ancestors and, how much they have diverged from each other.
Information used for Classification:
| Structural Information |
|
Cytological Information |
| Embryological Information |
|
Fossil Information |
The following is a brief description of the five kingdom system which is based on the following criteria:
1. The presence or absence of a nuclear membrane within the cell.
2. Unicellularity versus multicellularity.
3. Type of nutrition. (Heterotrophic or Autotrophic)
| Kingdoms: | Characteristics: | Examples: |
| 1) Monera | Primitive cell structure lacking a nuclear membrane. | All are prokaryotic. |
| Bacteria | ||
| Blue-Green Algae | ||
| 2) Protista | Predominately unicellular organisms with plant-like and/or animal-like characteristics. | |
| Protozoa | Animal-like in their mode of nutrition. | Paramecium, Amoeba |
| Algae | Plant-like in their mode of nutrition. | Spirogyra |
| 3) Fungi | Cells are usually organized into branched, multinucleated filaments which absorb digested food from their environment. | yeast, bread mold, mushroom |
| 4) Plant | Multicellular, photosynthetic organisms. | |
| Bryophytes | Lack vascular tissue; therefore, no true roots, stems, or leaves. | Moss |
| Tracheophytes | Possess vascular tissue, true roots, stems and leaves. | geranium, fern, bean, pine tree, maple tree, corn, etc. |
| 5) Animal | Multicellular organisms that ingest their food. | |
| Coelenterates | Two cell layers, hollow body cavity. | Hydra, Jellyfish |
| Annelids | Segmented body walls. | earthworm, sandworm |
| Arthropods | Jointed appendages, exoskeleton. | grasshopper, lobster, spider |
| Chordates | Dorsal nerve cord. | Shark, frog, human |
This five-kingdom system of classification is predicated on the idea that monerans are the most primitive. Most classification systems suggest relationships among organisms which may indicate common ancestry.
| Interactive Movie on the 5 Kingdoms |
Take a multiple-choice Biology quiz using PowerPoint
1. What is the difference between a reptile and an amphibian? answer
2. Which taxonomical term is the most specific term used to classify humans? answer
3. In the past, euglena and ameba were difficult to classify as either plants or animals. Currently, these organisms are classified as...answer
4. Which characteristics of organisms are most commonly used to place them in a specific kingdom in the five-kingdom classification system? answer
5. There are approzimately 4,250 species of mammals. What specific type of animal makes up nearly one-forth of all the mammal species? answer
6. Why do lifeguards use vinegar on Jellyfish stings? answer
7. What is krill? answer
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