Friday, May 12, 2006


Multicellular organisms are made up of more than one cell. The examples of multicellular organisms are all plants and animal. Multicellular organisms have cells which are different. Example the cells that build skin of human are different from those that build the inner organs. The cells of almost every multicellular organism are generated by repeated division from a single original cell; they form a clone. Normal human development and volvox were used as examples of multicellular organisms.

All different kinds of cells were derived from the fertilized egg cell through the process of differentiation. The process of differentiation allows the unspecialized cells to become specialized into one of the many cells that make up the body such as heart, liver or muscle cell. During the process of differentiation, there are certain cells which become inactivated while other genes are activated. Consequently, the cell which was differentiated expand with a specific structure that is shape and size to perform a specialize function. The process is complex to regulate.

The mammalian body is made up of three fundamental cells, these include germ line, somatic and stem cells. Germ line cells produce gamete (egg and sperm) and proceeds through the generation. Stem cells have ability to divide for imprecise period and produce specialized cells. When a sperm fertilizes an egg, the single cell is created which has ability to form the entire organism. The cell split into identical cells. The cells split at the earliest hours after fertilization. In humans, just about four days after fertilization and after several cycles of cell division. Consequently, the identical cells start to specialize by creating a hollow sphere of the cell.

Furthermore, humans have a cell mass and cells which are found in the inner cell mass create all tissues in the body. Even if cells in the cell mass can virtually every type of cell found in human, they cannot form organism. These cells are called pluripotent. Pluripotent stem cells go through cell specialization into a stem cell. This process produce cell that have special function. Examples include blood cell produce red blood cells, white blood and platelets and skin stem cell produce various kinds of skin cells.

Moreover, there are specialized part within the cells that are responsible for transportation of material, energy capture and release, protein building, excretion, passing information and also movement. A group of specialized tissue work together to form tissue, for instance muscle. Different tissues are in turn cooperating to make larger functions that serve the entire organism.

Volvox which some of whose species have as many as 50,000 or more cells linked together to form a hollow sphere. Volvox is more like a multicellular organism than a simple colony. Its entire flagella beat in synchrony as it spins through the water, and the colony is structurally and functionally polarized and can swim toward a distant source of light. The reproductive cells are usually limited to one end of the colony, where they divide to form new miniature (baby) colonies, which are firstly sheltered inside the parent sphere, its cells become specialized, and they cooperate. By specialization and assistance the cells combine to form a coordinated single organism with more capability than any of its component part.

Cells become specialized to perform different function in multicellular organisms through differentiations. Stem cell which is unspecialized cell is transformed in certain condition to perform specific functions. As a results stem cell become a specialized cell to perform special function.


Wikipedia Contributor. multicellular organisms, The free Encyclopedia [internet] 2006 May 06, 08:30 UTC [cited 2006 May 08] Available from:

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