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Characteristics of Micro-Organisms

The basic unit of all living things is the cell. The cell is the fundamental unit of biology, which states that all organisms are made up of cells also cells are derive from other pre-existing cells. An organism that has just a single cell is called (unicellular) while those with several distinct cell types with specialized functions are (Multicellular) organisms. 

All bacteria and protozoans are unicellular organisms; fungi may be uni or multicellur while an alga exists in the forms. All organisms are made of two distinct cell types, which we call prokaryotic and eukaryotic cell microbial world. They are different from each other in many ways, including size, structure, and genetic material. 

The most fundamental difference between prokaryotic and eukaryotic is reflected in their names; eukaryotic cell possess a true nucleus and several other distinct subcellular organelles that are bounded by a membranes. Prokaryotes have no such organelles.


Their ribosomes act as site of protein synthesis
Genetic information are encoded in the D.N.A
Cell contents are bounded by a plasma membrane.


In prokaryotic cell, Cillia are present in their external body, flagella, if present they composed of flagellin which provide Rotating motility. In their external body the membrane organelles are absent.

Differences between Prokaryotes and Eukaryotes Cell.

Prokaryotic Cells (Bacteria, Blue Green Algae) are free in cytoplasm, they ranges between the size of 1-5micrometres, they contain singular circular chromosome or nucleoid, their respiratory enzymes are bound to plasma membrane.

Eukaryotic Cells (Fungi, Algae, Protozoa, Plants and Animal)...their respiratory system is located in the mitochondria, they contain larger Ribosomes, they have multiple chromosomes generally in pairs, they ranges between the size of 10-100micrometres,there is presence of Golgi body, endoplasmic recticulum, their cell wall is based on cellulose or chitin.


Bacteria are much more smaller than eucaryotic cells; most bacteria fall into a size range of about 1-5micrometre. Some of the smallest bacteria, such as the Mycoplasma measure less than 1micr-metre, and they ate too small to be Seen by an ordinary light microscope, because of their extremely small size, it can be clearly Seen by electron microscope which will enable us to see the detailed structures of the bacterial cells. Using the light microscope however, it is possible to recognize the differences I'm the shape and  arrangement of bacteria. Most bacteria have one of these shapes.

Rod shaped (bacillus)
Spherical (coccus)

Curved: these range from comma shaped to corkscrew- shaped. All these shapes have their own advantages to their owners; rods, with a large surface area are able to take up nutrients from the environment, while the cocci are less prone to drying out. The spiral forms are usually motile; their shapes aid their movement through an aqueous medium. 

When they divide, they remained attached to one another. As well as these characteristic cell shapes, bacteria may also be found grouped together in particular formation. Rod-shaped bacteria only divide In a single plane and may therefore be found on chains, while spiral forms also divide in one plane, but tend not to stick together.

Submitted by Annix

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