THE ORDER OF THINGS

Imagine getting a mix CD full of music, but when you load it into your iTunes you realize that each song loads only as a random number.  Therefore when listening to the various tracks, you have to constantly remind yourself which number correlates to which song.  If you upload a few more CDs like this, you will eventually end up with too many songs to remember their numerical association.  Thankfully song makers realized this possibility and therefore labeled their songs: title, artist, album, genre, etc.  Now apply this to biology.  As the science of life, each form of life needs a classification in order to avoid confusion.  This classification process is called taxonomy.

Image found at: http://www.electrical-picture.com/kingdom-phylum-class-order-family-genus-species/

Looking at the image above, you see that the naming of a species starts big and works down.

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

The domain classification is a recent addition which classifies organisms based on whether each organism has a nucleus at the center of each cell, or not.  Those cellular organisms with nuclei all belong to Domain Eukarya.  Those without belong to either Domain Archaea, or Domain Bacteria, dependent upon each organism's characteristics; these two domain names double as kingdom names; all members of these two domains are single-celled. 

The six kingdoms:

1. Animalia
2. Plantae
3. Fungi
4. Protista
5. Archaea
6. Bacteria

Each kingdom contains organisms with similar characteristics broadly defined by the organism's source of energy.  Plants make their own through photosynthesis.  Fungi absorb nutrients from their environment to give them energy.  Animals eat their nutrition.  Dependent upon the species, members of the three remaining kingdoms either eat or absorb nutrition or create their own energy.  

Next comes phylum, which further breaks down each kingdom into groups based very roughly on physical characteristics.  To further delineate, each phylum is further broken down into classes, then orders, then families, then genus, then finally species.  

Modern biologists focus most on genus and species.  When describing genus and species, capitalize the Genus, but do not do so for the species; you may abbreviate the genus with simply a period after the first letter, do not abbreviate the species.  An example: E. coli.  

Practically, consider how knowing the classification of an organism may affect treatments for disease, or likelihood of research significance, and so on.  For instance, an understanding of this classification system helps to explain why we use the same antibiotics for all strep infections regardless of which species is actually causing the infection; since all members of genus Streptococcus share susceptibility to the same antibiotics.  Nobody is expected to remember the taxonomy of each species, but to know classification system is important.  

Need some help?  Just consider the following: 

King          Phillip      Came    Over     For       Great    Spaghetti

(kingdom)  (phylum)  (class)  (order)  (family)  (genus)  (species)

Image found at: http://poppadomsfoodblog.blogspot.com/2011/05/eat-breakfast-like-king.html