Levels of Organization 

Life is a complex mechanism. It is a series of levels and each level has some organisms existing in that level. 

There are various levels of life.

These starts from the cells.

Cell: A cell is the basic unit of life. It is the smallest unit of life capable of perfoming all charateristics of living organisms. It is refered to as the basic structural and functional unit of life. It is made up of organells and inclusions.

In looking at a cell care must be taken to understand that some organisms are found in their cellular forms. We must also understand that some cellular organisms are found either in filamentous forms or in colony.

Note that these are not multicellular organisms they are still unicellular only in colony or filamentous forms. Examples of the three types of cellular organisms are as follows:

• Single free living - Amoeba sp., Euglena sp.

• Fillamentous - Spirogyra sp.,Oscillatoria sp., filamentous Bacteria

• Colony - Volvox sp.

Tissue: A tissue is a group of cells, not necessarily identical, but from the same origin, that together carry out a specific function. It can also be refered to as a group of biological cells that perform a similar function.

Some organisms such as Hydra sp and  the Jelly fish are in the tissue level.

Organ: This is a group of specialised tissues coming together to perform a particular function. Such functions form part of the metabolism of a living organism. In other words it can be said that different tissues are grouped together to forma structure called an organ. Examples of organs include the heart which is made up of muscle tissue, connective tissue,and the vascular tissue, these work in a coordinated manner and enable the heart to carry out the broader function of pumping blood.

System: a series of different functionally related organ form an organ system. this means that the heart, the blood and the blood vessels makes up the circulatory system.

Having considered the complexity of organisms it is no wonder that Carolus Linnaeus (1707-1778), a Swedish naturalist, decided to name and classify living organisms. The study of the principles of classification is known as Taxonomy or Systematics. In classifying into groups, important features that are found in a large number of organisms are first use. This progressively becomes more specific as more as divisions and subdivisions within the main group are based on progressively less important features.

This Hieraarchy is as follows:

Kingdom

     Phylum

        Class

            Order

               Family

                  Genus

                      Species